In the version of this article initially published, the last sentence of the second paragraph in ... more In the version of this article initially published, the last sentence of the second paragraph in the right column on page 1065 read "that is, the following term was added to the RT prediction: [ slow (s,t) - fast (s,t)], where is a free parameter." A variable in the equation contained in this sentence was incorrect. The sentence should read "that is, the following term was added to the RT prediction: [ slow (s,t) - fast (s,t)], where is a free parameter." The error has been corrected in the HTML and PDF versions of the article.
Patients with schizophrenia often suffer comorbid substance abuse regardless of gender. However, ... more Patients with schizophrenia often suffer comorbid substance abuse regardless of gender. However, the vast majority of studies are only conducted in male subjects. Therefore, the aim of these experiments is to assess addictive behaviors of both sexes in a neurodevelopmental model of schizophrenia induced by prenatal methylazoxymethanol (MAM) acetate exposure. MAM (22 mg/kg) was administered intraperitoneally on gestational day 17. Two studies were performed in the offspring: (1) an alcohol-drinking procedure to assess daily intake of 20% alcohol and relapse-like behavior after a period of forced abstinence; (2) Methamphetamine (METH) intravenous self administration (IVSA) followed by forced abstinence and reinstatement phases. MAM exposure during the prenatal period did not change alcohol drinking regardless of sex. However, MAM females showed higher alcohol consumption in comparison to MAM males. The METH IVSA study revealed only a modest increase of drug consumption in MAM males, while there was no difference between the female groups. Reinstatement data showed no effect of the MAM model in either sex, but suggested increased responding in female rats. This study suggests that female sex and schizophrenia-like phenotype may work synergistically to enhance alcohol consumption. However, future research is needed to establish paradigms in which these findings would be readily assessed to test anti-addiction treatments.
Feldon J., 2004, Regional dissociations within the hippocampus -Memory and anxiety, Neurosci. Bio... more Feldon J., 2004, Regional dissociations within the hippocampus -Memory and anxiety, Neurosci. Biobehav. Rev., 28, 273-283. [2] Carobrez A.P, Bertoglio, L.J., 2005, Ethological and Temporal analyses of anxiety-like behavior: The elevated plus maze model 20 years on, Neurosci. Biobehav. Rev., 29, 8, 1193-205. P.1.d.012 Propranolol restores the anxiolytic action of midazolan during the retest in the elevated plus maze test Purpose: Rats submitted to the elevated plus maze (EPM) demonstrate increased exploratory activity towards the open arms after treatment with anxiolytic drugs. However, in a second exposure (retest), the subjects, display increased avoidance to the open arms regardless receiving saline or an anxiolytic drug, such as, midazolam (MDZ). Retesting rats in the EPM has proven to be suitable to assess aspects related to learning/memory and anxiety [1]. Adrenergic beta blockade, such as, propranolol (PROP) impairs the aversive memory consolidation, in animals and humans subjects [2]
Patients affected by autosomic recessive juvenile parkinsonism (ARJP) exhibit parkin gene mutatio... more Patients affected by autosomic recessive juvenile parkinsonism (ARJP) exhibit parkin gene mutations with brain decrease in dopamine D2/D3 binding sites. To date, there are no data indicating whether the reduction in dopamine D3 receptors (DRD3) may be associated with the expression of specific parkin variants. In the present study we investigated parkin expression profile in DRD3 knockout mice brains. RT-PCR analysis was performed to assess qualitative changes in parkin isoforms' distribution pattern and in exons' expression both in wild type controls and dopamine D3 receptor's knock-out mice. Real-time PCR was performed to quantify single exons mRNA. Results demonstrated that exons 1, 2, 4, 6, 7, 8, were more expressed in wild type compared to dopamine D3 receptor KO mice brains while some other (3, 9, 10) were lower expressed. The expression levels of exons 5, 11 and 12 did not change in both animal groups. Our analysis was confirmed by western blot, which showed that parkin protein levels were influenced by the absence of DRD3.
Administration of drugs activating cannabinoid CB1 receptors in the brain induces memory deficit ... more Administration of drugs activating cannabinoid CB1 receptors in the brain induces memory deficit in rodents, and blockade of these receptors may restore memory capacity in these animals. Central administration of β-amyloid or β-amyloid fragments may also lead to memory disturbances. This study was undertaken to study the involvement of cannabinoid CB1 receptors in amnesia induced by β-amyloid fragments in mice tested in a step-through passive avoidance paradigm. Pre-training intracerebroventricular (i.c.v.) injection of β-amyloid fragments, β-amyloid peptide-(25–35) (4, 8 or 16 nmol/mouse) or β-amyloid peptide-(1–42) (200, 400, 800 pmol/mouse) 7 days prior to the learning trial reduced in a dose-dependent manner the retention of passive avoidance response. This effect was observed in two retention tests, 1 and 7 days after the learning trial. The two β-amyloid fragments showed similar potency in reducing retention of passive avoidance behavior. This effect was counteracted by a single intraperitoneal (i.p.) injection of the cannabinoid CB1 receptor antagonist, N-(piperidin-l-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide hydrochloride (SR141716A, 1 mg/kg), made 30 min prior to the second retention test. The injection of SR141716A per se did not affect memory capacity of mice. The i.c.v. administration of β-amyloid peptide-(25–35) (8 nmol/mouse) or of β-amyloid peptide-(1–42) (400 pmol/mouse) made 30 min prior to the learning trial failed to affect the retention capacity of mice as measured 1 and 7 days later. Also, the i.p. injection of SR 141716A (1 mg/kg) made 30 min prior to the learning trial did not influence the behavioral response of mice injected with β-amyloid peptide-(25–35) (8 nmol/mouse) or of β-amyloid peptide-(1–42) (400 pmol/mouse) 7 days prior to the learning trial. These results show that β-amyloid fragments induce a dose-dependent memory deficit. Their effect on memory retention depends upon the time of administration and seems to involve cannabinoid CB1 receptors in the brain.
Please cite this article in press as: Navarria A, et al. The dual blocker of FAAH/TRPV1 N-arachid... more Please cite this article in press as: Navarria A, et al. The dual blocker of FAAH/TRPV1 N-arachidonoylserotonin reverses the behavioral despair induced by stress in rats and modulates the HPA-axis. Pharmacol Res (2014), http://dx.
These experiments were made to study the mechanisms underlying the antidepressant-like effects of... more These experiments were made to study the mechanisms underlying the antidepressant-like effects of the β 3 adrenoceptor agonist amibegron (SR58611A). To this purpose, the expression levels of the hippocampal cyclic adenosine monophosphate (cAMP)-response element binding protein (CREB), brain-derived neurotrophic factor (BDNF), B-cell lymphoma-2 (Bcl-2) and Bax proteins were assessed, by using western blot analysis, in rats tested in the forced swim test (FST). Under basal conditions (no previous exposure to stressors), different groups of male Wistar rats received acutely or repeatedly (once/day for 7 days) intraperitoneal (i.p.) injections of amibegron (1, 5 and 10 mg/kg), the tricyclic antidepressant (TCA) clomipramine (50 mg/kg), the selective serotonin reuptake inhibitor (SSRI) citalopram (15 mg/kg) or their vehicles. The influence of stress-related conditions was studied in rats subjected to acute (4 h) or repeated (4 h/day for 7 days) restraint stress, applied prior to the FST procedure. Compared to the control groups, both stressor procedures increased the immobility time in the FST and reduced hippocampal BDNF and Bcl-2/Bax ratio proteins expression, which were counteracted by amibegron (5 and 10 mg/kg) treatment. Opposite effects were found in the CREB expression, since it was lower after acute and higher after repeated stress procedure, respectively. Again, these effects were reversed by amibegron treatment. Different results were obtained in animals treated with clomipramine or citalopram. Hence, it is likely that the observed behavioral effects of amibegron could be due, at least in part, to its action on hippocampal expression of neurotrophic and/or anti-apoptotic factors, supporting the hypothesis that β 3 adrenoceptors may be a therapeutic target for the treatment of stress-related disorders.
Pharmacology Biochemistry and Behavior, Sep 30, 2008
The present study was made to investigate the role of tachykinin NK2 receptors in the expression ... more The present study was made to investigate the role of tachykinin NK2 receptors in the expression of stress-related behaviors in animals. Under basal conditions, intraperitoneal (i.p.) administration of the selective tachykinin NK2 receptor antagonist, saredutant (1 and 3 mg/kg) or diazepam (1 mg/kg) exerted anxiolytic-like effects in rodents, as they reduced grooming score of Wistar male rats tested in the novelty-induced grooming sampling test (NGT) and increased percentage of time and entries in open arms of Swiss male mice tested in the elevated plus maze (EPM) test. After previous exposure to stress-related conditions, as induced by a 2-min forced swim made 5 min prior to the EPM test, saredutant but not diazepam, exhibited anxiolytic-like effects in mice. To study the antidepressant-like activity of tachykinin NK2 receptor antagonist under basal conditions, different groups of rats were injected i.p. with saredutant (2.5, 5 and 10 mg/kg) or the tricyclic antidepressant, clomipramine (50 mg/kg) and tested in the forced swim test (FST), a widely used antidepressant-responsive test. The influence of stress-related conditions was studied in rats subjected to electric foot-shocks (1 mA, 1 s) 24, 5 and 1 h prior to FST, after drugs injection. In the FST, clomipramine decreased the immobility time only under basal conditions, but not after application of acute foot-shocks. To the contrary, saredutant-treated rats also exhibited more active behavior in FST after previous exposure to stressors. These results give further support to the hypothesis that tachykinin NK2 receptors may be a therapeutic target for pharmacological treatment of stress-related diseases, such as anxiety and depression.
Abnormalities in social behavior are found in almost all psychiatric disorders, such as anxiety, ... more Abnormalities in social behavior are found in almost all psychiatric disorders, such as anxiety, depression, autism, and schizophrenia. Thus, comprehension of the neurobiological basis of social interaction is important for a better understanding of numerous pathologies and improved treatments. Several findings have suggested that an alteration of cannabinoid receptor type 1 (CB1) receptor function could be involved in the pathophysiology of such disorders. However, the role of CB1 receptors is still unclear, and their localisation on different neuronal subpopulations may produce distinct outcomes. To dissect the role of CB1 receptors in different neuronal populations, we used male knockout mice and their respective control littermates [total deletion (CB1 À/À ); specific deletion on cortical glutamatergic neurons (Glu-CB1 À/À ) or on GABAergic interneurons (GABA-CB1 À/À ), and wild-type (WT) mice treated with the CB1 antagonist/inverse agonist SR141716A (3 mg/kg). Mice were required to perform different social tasksdirect social interaction and social investigation. Direct interaction of two male mice was not modified in any group; however, when they were paired with females, Glu-CB1 À/À mice showed reduced interaction. Also, exploration of the male stimulus subject in the three-chamber social investigation test was almost unaffected. The situation was completely different when a female was used as the stimulus subject. In this case, Glu-CB1 À/À mice showed reduced interest in the social stimulus, mimicking the phenotype of CB1 À/À or WT mice treated with SR141716A. GABA-CB1 À/À mice showed the opposite phenotype, by spending more time investigating the social stimulus. In conclusion, we provide evidence that CB1 receptors specifically modulate the social investigation of female mice in a neuronal subtype-specific manner.
A large body of evidence corroborates the notion that deficiencies of serotonergic system are lik... more A large body of evidence corroborates the notion that deficiencies of serotonergic system are likely involved in the pathogenesis of both depression and anxiety. Activation of β 3 adrenoceptors has been shown to increase brain tryptophan content suggesting an elevation of brain serotonin (5HT) synthesis. SR58611A is a selective β 3 adrenergic agent possessing a profile of antidepressant activity in routine rodents' experimental models of depression. The present study was undertaken to evaluate in rodents the antidepressant properties of SR58611A and to assess its putative anxiolytic value in experimental models of depression and anxiety. Compared to the control group, SR58611A (0.1, 1, 5 or 10 mg/kg) caused a dose-dependent reduction in immobility of Wistar male rats in the forced swim test. The maximum dose appeared to be equivalent to an effective dose of clomipramine (50 mg/kg). In addition, acute injection of SR58611A induced in rats a dose-dependent decrease in grooming response to a novel environment (novelty-induced grooming test). For any dose, the effect was lower than that of diazepam (1 mg/kg). Chronic treatment with SR58611A resulted also in an increased social interaction time in the social interaction test without affecting motor activity of rats. Furthermore, similarly to diazepam a chronic treatment with the highest doses of SR58611A was followed by increased exploratory behavior in Swiss male mice exposed to the elevated plus maze test. These effects are mediated by β 3 adrenoceptors since i.p. pretreatment with the selective β 3 adrenoceptor antagonist SR59230A (5 mg/kg) blocked the effects of SR58611A. Finally, also the 5HT antagonist methysergide (2 mg/kg) prevented the antidepressant and anxiolytic-like activity of SR58611A indicating that 5HT transmission is strictly involved in its action.
Abnormalities in social behavior are found in almost all psychiatric disorders, such as anxiety, ... more Abnormalities in social behavior are found in almost all psychiatric disorders, such as anxiety, depression, autism, and schizophrenia. Thus, comprehension of the neurobiological basis of social interaction is important for a better understanding of numerous pathologies and improved treatments. Several findings have suggested that an alteration of cannabinoid receptor type 1 (CB1) receptor function could be involved in the pathophysiology of such disorders. However, the role of CB1 receptors is still unclear, and their localisation on different neuronal subpopulations may produce distinct outcomes. To dissect the role of CB1 receptors in different neuronal populations, we used male knockout mice and their respective control littermates [total deletion (CB1 À/À ); specific deletion on cortical glutamatergic neurons (Glu-CB1 À/À ) or on GABAergic interneurons (GABA-CB1 À/À ), and wild-type (WT) mice treated with the CB1 antagonist/inverse agonist SR141716A (3 mg/kg). Mice were required to perform different social tasksdirect social interaction and social investigation. Direct interaction of two male mice was not modified in any group; however, when they were paired with females, Glu-CB1 À/À mice showed reduced interaction. Also, exploration of the male stimulus subject in the three-chamber social investigation test was almost unaffected. The situation was completely different when a female was used as the stimulus subject. In this case, Glu-CB1 À/À mice showed reduced interest in the social stimulus, mimicking the phenotype of CB1 À/À or WT mice treated with SR141716A. GABA-CB1 À/À mice showed the opposite phenotype, by spending more time investigating the social stimulus. In conclusion, we provide evidence that CB1 receptors specifically modulate the social investigation of female mice in a neuronal subtype-specific manner.
Cannabinoid Modulation of Emotion, Memory, and Motivation, 2015
The endogenous cannabinoid system (ECS) works as pro-homeostatic and pleiotropic signaling system... more The endogenous cannabinoid system (ECS) works as pro-homeostatic and pleiotropic signaling system activated in a time-and tissue-specific way during physiological conditions, which include cognitive, emotional and motivational processes. It is composed of two G protein-coupled receptors (the cannabinoid receptors types 1 and 2 [CB1 and CB2] for marijuana's psychoactive ingredient Δ9-tetrahydrocannabinol [Δ9-THC]), their endogenous small lipid ligands (anandamide [AEA] and 2-arachidonoylglycerol [2-AG], also known as endocannabinoids), and the proteins for endocannabinoid biosynthesis and deactivation. Data from preclinical and clinical studies have reported that a hypofunction of the endocannabinoid signaling could induce a depressive-like phenotype; consequently, enhancement of endocannabinoid signaling could be a novel therapeutic avenue for the treatment of depression. To this aim there have been proposed cannabinoid receptor agonists or synthetic molecules that inhibit endocannabinoid degradation. The latter ones do not induce the psychotropic side effects by direct CB1 receptor activation, but rather elicit antidepressant-like effects by enhancing the monoaminergic neurotransmission, promoting hippocampal neurogenesis and normalizing the hyperactivity of hypothalamic-pituitary-adrenal axis, similarly as the standard antidepressants. The dysfunction of elements belonging to the ECS and the possible therapeutic use of endocannabinoid deactivation inhibitors and phytocannabinoids in depression is discussed in this chapter.
Ruda-Kucerova J, Amchova P, Babinska Z, Dusek L, Micale V and Sulcova A (2015) Sex differences in... more Ruda-Kucerova J, Amchova P, Babinska Z, Dusek L, Micale V and Sulcova A (2015) Sex differences in the reinstatement of methamphetamine seeking after forced abstinence in Preventing relapse to drug abuse is one of the struggles faced by clinicians in order to treat patients with substance use disorders (DSM-5). There is a large body of clinical evidence suggesting differential characteristics of the disorder in men and women, which is in line with preclinical findings as well. The aim of this study was to assess differences in relapse-like behavior in methamphetamine (METH) seeking after a period of forced abstinence, which simulates the real clinical situation very well. Findings from such study might add new insights in gender differences in relapse mechanisms to previous studies, which employ a classical drug or cue-induced reinstatement procedure following the extinction training. Adult male and female Sprague-Dawley rats were used in IV self-administration procedure conducted in operant boxes using nose-poke operandi (Coulborn Instruments, USA). Active nose-poke resulted in activation of the infusion pump to deliver one intravenous infusion of METH (0.08 mg/kg). After baseline drug intake was established (maintenance phase), a period of forced abstinence was initiated and rats were kept singly in their home cages for 14 days. Finally, one reinstatement session in operant boxes was conducted. Females were found to self-administer significantly lower dose of METH. The relapse rate was assessed as a number of active nosepokes during the reinstatement session, expressed as a percentage of active nose-poking during the maintenance phase. Females displayed approximately 300% of active nosepokes compared to 50% in males. This indicates higher vulnerability to relapse of METH seeking behavior in female rats. This effect was detected in all females, independently of current phase of their estrous cycle. Therefore, this paradigm using operant drug self-administration and reinstatement of drug-seeking after forced abstinence model can be used for preclinical screening for potential new anti-relapse medications specific for women.
The contribution of two major endocannabinoids, 2-arachidonoylglycerol (2-AG) and anandamide (AEA... more The contribution of two major endocannabinoids, 2-arachidonoylglycerol (2-AG) and anandamide (AEA), in the regulation of fear expression is still unknown. We analyzed the role of different players of the endocannabinoid system on the expression of a strong auditory-cued fear memory in male mice by pharmacological means. The cannabinoid receptor type 1 (CB1) antagonist SR141716 (3 mg/kg) caused an increase in conditioned freezing upon repeated tone presentation on three consecutive days. The cannabinoid receptor type 2 (CB2) antagonist AM630 (3 mg/kg), in contrast, had opposite effects during the first tone presentation, with no effects of the transient receptor potential vanilloid receptor type 1 (TRPV1) antagonist SB366791 (1 and 3 mg/kg). Administration of the CB2 agonist JWH133 (3 mg/kg) failed to affect the acute freezing response, whereas the CB1 agonist CP55,940 (50 μg/kg) augmented it. The endocannabinoid uptake inhibitor AM404 (3 mg/kg), but not VDM11 (3 mg/kg), reduced the ...
The cannabinoid CB1 and CB2 receptors, the endogenous endocannabinoid (EC) ligands anandamide (AE... more The cannabinoid CB1 and CB2 receptors, the endogenous endocannabinoid (EC) ligands anandamide (AEA) and 2-arachidonylethanolamide, and the degradative enzymes fatty acid amide hydrolase (FAAH) and monoglyceride lipase (ML) are key elements of the EC system implicated in different physiological functions including cognition, motor activity and immune responses. Thus, both the possible neuroprotective role of ECs and their modulating action on neurotransmitter systems affected in several neurodegenerative diseases such as Alzheimer's disease (AD), Huntington's disease (HD) and multiple sclerosis (MS) are currently under investigation. Accumulating data show an unbalance in the EC system (i.e. decrease of neuronal cannabinoid CB1 receptors, increase of glial cannabinoid CB2 receptors and over-expression of FAAH in astrocytes) in experimental models of AD as well as in post-mortem brain tissue of AD patients, suggesting its possible role in inflammatory processes and in neuroprotection. However, the mechanisms of the EC modulation of immune response are not fully understood.
Increasing evidence suggests a close relationship between the endocannabinoid system and schizoph... more Increasing evidence suggests a close relationship between the endocannabinoid system and schizophrenia. The endocannabinoid system comprises of two G protein-coupled receptors (the cannabinoid receptors 1 and 2 [CB1 and CB2] for marijuana's psychoactive principle 9 -tetrahydrocannabinol), their endogenous small lipid ligands (namely anandamide [AEA] and 2-arachidonoylglycerol [2-AG], also known as endocannabinoids), and proteins for endocannabinoid biosynthesis and degradation. It has been suggested to be a pro-homeostatic and pleiotropic signalling system activated in a time-and tissue-specific manner during pathophysiological conditions. In the brain, activation of this system impacts the release of numerous neurotransmitters in various systems and cytokines from glial cells. Hence, the endocannabinoid system is strongly involved in neuropsychiatric disorders, such as schizophrenia. Therefore, adolescence use of Cannabis may alter the endocannabinoid signalling and pose a potential environmental risk to develop psychosis. Consistently, preclinical and clinical studies have found a dysregulation in the endocannabinoid system such as changed expression of CB1 and CB2 receptors or altered levels of AEA and 2-AG . Thus, due to the partial efficacy of actual antipsychotics, compounds which modulate this system may provide a novel therapeutic target for the treatment of schizophrenia. The present article reviews current available knowledge on herbal, synthetic and endogenous cannabinoids with respect to the modulation of schizophrenic symptomatology. Furthermore, this review will be highlighting the therapeutic potential of cannabinoid-related compounds and presenting some promising patents targeting potential treatment options for schizophrenia.
In the version of this article initially published, the last sentence of the second paragraph in ... more In the version of this article initially published, the last sentence of the second paragraph in the right column on page 1065 read "that is, the following term was added to the RT prediction: [ slow (s,t) - fast (s,t)], where is a free parameter." A variable in the equation contained in this sentence was incorrect. The sentence should read "that is, the following term was added to the RT prediction: [ slow (s,t) - fast (s,t)], where is a free parameter." The error has been corrected in the HTML and PDF versions of the article.
Patients with schizophrenia often suffer comorbid substance abuse regardless of gender. However, ... more Patients with schizophrenia often suffer comorbid substance abuse regardless of gender. However, the vast majority of studies are only conducted in male subjects. Therefore, the aim of these experiments is to assess addictive behaviors of both sexes in a neurodevelopmental model of schizophrenia induced by prenatal methylazoxymethanol (MAM) acetate exposure. MAM (22 mg/kg) was administered intraperitoneally on gestational day 17. Two studies were performed in the offspring: (1) an alcohol-drinking procedure to assess daily intake of 20% alcohol and relapse-like behavior after a period of forced abstinence; (2) Methamphetamine (METH) intravenous self administration (IVSA) followed by forced abstinence and reinstatement phases. MAM exposure during the prenatal period did not change alcohol drinking regardless of sex. However, MAM females showed higher alcohol consumption in comparison to MAM males. The METH IVSA study revealed only a modest increase of drug consumption in MAM males, while there was no difference between the female groups. Reinstatement data showed no effect of the MAM model in either sex, but suggested increased responding in female rats. This study suggests that female sex and schizophrenia-like phenotype may work synergistically to enhance alcohol consumption. However, future research is needed to establish paradigms in which these findings would be readily assessed to test anti-addiction treatments.
Feldon J., 2004, Regional dissociations within the hippocampus -Memory and anxiety, Neurosci. Bio... more Feldon J., 2004, Regional dissociations within the hippocampus -Memory and anxiety, Neurosci. Biobehav. Rev., 28, 273-283. [2] Carobrez A.P, Bertoglio, L.J., 2005, Ethological and Temporal analyses of anxiety-like behavior: The elevated plus maze model 20 years on, Neurosci. Biobehav. Rev., 29, 8, 1193-205. P.1.d.012 Propranolol restores the anxiolytic action of midazolan during the retest in the elevated plus maze test Purpose: Rats submitted to the elevated plus maze (EPM) demonstrate increased exploratory activity towards the open arms after treatment with anxiolytic drugs. However, in a second exposure (retest), the subjects, display increased avoidance to the open arms regardless receiving saline or an anxiolytic drug, such as, midazolam (MDZ). Retesting rats in the EPM has proven to be suitable to assess aspects related to learning/memory and anxiety [1]. Adrenergic beta blockade, such as, propranolol (PROP) impairs the aversive memory consolidation, in animals and humans subjects [2]
Patients affected by autosomic recessive juvenile parkinsonism (ARJP) exhibit parkin gene mutatio... more Patients affected by autosomic recessive juvenile parkinsonism (ARJP) exhibit parkin gene mutations with brain decrease in dopamine D2/D3 binding sites. To date, there are no data indicating whether the reduction in dopamine D3 receptors (DRD3) may be associated with the expression of specific parkin variants. In the present study we investigated parkin expression profile in DRD3 knockout mice brains. RT-PCR analysis was performed to assess qualitative changes in parkin isoforms' distribution pattern and in exons' expression both in wild type controls and dopamine D3 receptor's knock-out mice. Real-time PCR was performed to quantify single exons mRNA. Results demonstrated that exons 1, 2, 4, 6, 7, 8, were more expressed in wild type compared to dopamine D3 receptor KO mice brains while some other (3, 9, 10) were lower expressed. The expression levels of exons 5, 11 and 12 did not change in both animal groups. Our analysis was confirmed by western blot, which showed that parkin protein levels were influenced by the absence of DRD3.
Administration of drugs activating cannabinoid CB1 receptors in the brain induces memory deficit ... more Administration of drugs activating cannabinoid CB1 receptors in the brain induces memory deficit in rodents, and blockade of these receptors may restore memory capacity in these animals. Central administration of β-amyloid or β-amyloid fragments may also lead to memory disturbances. This study was undertaken to study the involvement of cannabinoid CB1 receptors in amnesia induced by β-amyloid fragments in mice tested in a step-through passive avoidance paradigm. Pre-training intracerebroventricular (i.c.v.) injection of β-amyloid fragments, β-amyloid peptide-(25–35) (4, 8 or 16 nmol/mouse) or β-amyloid peptide-(1–42) (200, 400, 800 pmol/mouse) 7 days prior to the learning trial reduced in a dose-dependent manner the retention of passive avoidance response. This effect was observed in two retention tests, 1 and 7 days after the learning trial. The two β-amyloid fragments showed similar potency in reducing retention of passive avoidance behavior. This effect was counteracted by a single intraperitoneal (i.p.) injection of the cannabinoid CB1 receptor antagonist, N-(piperidin-l-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide hydrochloride (SR141716A, 1 mg/kg), made 30 min prior to the second retention test. The injection of SR141716A per se did not affect memory capacity of mice. The i.c.v. administration of β-amyloid peptide-(25–35) (8 nmol/mouse) or of β-amyloid peptide-(1–42) (400 pmol/mouse) made 30 min prior to the learning trial failed to affect the retention capacity of mice as measured 1 and 7 days later. Also, the i.p. injection of SR 141716A (1 mg/kg) made 30 min prior to the learning trial did not influence the behavioral response of mice injected with β-amyloid peptide-(25–35) (8 nmol/mouse) or of β-amyloid peptide-(1–42) (400 pmol/mouse) 7 days prior to the learning trial. These results show that β-amyloid fragments induce a dose-dependent memory deficit. Their effect on memory retention depends upon the time of administration and seems to involve cannabinoid CB1 receptors in the brain.
Please cite this article in press as: Navarria A, et al. The dual blocker of FAAH/TRPV1 N-arachid... more Please cite this article in press as: Navarria A, et al. The dual blocker of FAAH/TRPV1 N-arachidonoylserotonin reverses the behavioral despair induced by stress in rats and modulates the HPA-axis. Pharmacol Res (2014), http://dx.
These experiments were made to study the mechanisms underlying the antidepressant-like effects of... more These experiments were made to study the mechanisms underlying the antidepressant-like effects of the β 3 adrenoceptor agonist amibegron (SR58611A). To this purpose, the expression levels of the hippocampal cyclic adenosine monophosphate (cAMP)-response element binding protein (CREB), brain-derived neurotrophic factor (BDNF), B-cell lymphoma-2 (Bcl-2) and Bax proteins were assessed, by using western blot analysis, in rats tested in the forced swim test (FST). Under basal conditions (no previous exposure to stressors), different groups of male Wistar rats received acutely or repeatedly (once/day for 7 days) intraperitoneal (i.p.) injections of amibegron (1, 5 and 10 mg/kg), the tricyclic antidepressant (TCA) clomipramine (50 mg/kg), the selective serotonin reuptake inhibitor (SSRI) citalopram (15 mg/kg) or their vehicles. The influence of stress-related conditions was studied in rats subjected to acute (4 h) or repeated (4 h/day for 7 days) restraint stress, applied prior to the FST procedure. Compared to the control groups, both stressor procedures increased the immobility time in the FST and reduced hippocampal BDNF and Bcl-2/Bax ratio proteins expression, which were counteracted by amibegron (5 and 10 mg/kg) treatment. Opposite effects were found in the CREB expression, since it was lower after acute and higher after repeated stress procedure, respectively. Again, these effects were reversed by amibegron treatment. Different results were obtained in animals treated with clomipramine or citalopram. Hence, it is likely that the observed behavioral effects of amibegron could be due, at least in part, to its action on hippocampal expression of neurotrophic and/or anti-apoptotic factors, supporting the hypothesis that β 3 adrenoceptors may be a therapeutic target for the treatment of stress-related disorders.
Pharmacology Biochemistry and Behavior, Sep 30, 2008
The present study was made to investigate the role of tachykinin NK2 receptors in the expression ... more The present study was made to investigate the role of tachykinin NK2 receptors in the expression of stress-related behaviors in animals. Under basal conditions, intraperitoneal (i.p.) administration of the selective tachykinin NK2 receptor antagonist, saredutant (1 and 3 mg/kg) or diazepam (1 mg/kg) exerted anxiolytic-like effects in rodents, as they reduced grooming score of Wistar male rats tested in the novelty-induced grooming sampling test (NGT) and increased percentage of time and entries in open arms of Swiss male mice tested in the elevated plus maze (EPM) test. After previous exposure to stress-related conditions, as induced by a 2-min forced swim made 5 min prior to the EPM test, saredutant but not diazepam, exhibited anxiolytic-like effects in mice. To study the antidepressant-like activity of tachykinin NK2 receptor antagonist under basal conditions, different groups of rats were injected i.p. with saredutant (2.5, 5 and 10 mg/kg) or the tricyclic antidepressant, clomipramine (50 mg/kg) and tested in the forced swim test (FST), a widely used antidepressant-responsive test. The influence of stress-related conditions was studied in rats subjected to electric foot-shocks (1 mA, 1 s) 24, 5 and 1 h prior to FST, after drugs injection. In the FST, clomipramine decreased the immobility time only under basal conditions, but not after application of acute foot-shocks. To the contrary, saredutant-treated rats also exhibited more active behavior in FST after previous exposure to stressors. These results give further support to the hypothesis that tachykinin NK2 receptors may be a therapeutic target for pharmacological treatment of stress-related diseases, such as anxiety and depression.
Abnormalities in social behavior are found in almost all psychiatric disorders, such as anxiety, ... more Abnormalities in social behavior are found in almost all psychiatric disorders, such as anxiety, depression, autism, and schizophrenia. Thus, comprehension of the neurobiological basis of social interaction is important for a better understanding of numerous pathologies and improved treatments. Several findings have suggested that an alteration of cannabinoid receptor type 1 (CB1) receptor function could be involved in the pathophysiology of such disorders. However, the role of CB1 receptors is still unclear, and their localisation on different neuronal subpopulations may produce distinct outcomes. To dissect the role of CB1 receptors in different neuronal populations, we used male knockout mice and their respective control littermates [total deletion (CB1 À/À ); specific deletion on cortical glutamatergic neurons (Glu-CB1 À/À ) or on GABAergic interneurons (GABA-CB1 À/À ), and wild-type (WT) mice treated with the CB1 antagonist/inverse agonist SR141716A (3 mg/kg). Mice were required to perform different social tasksdirect social interaction and social investigation. Direct interaction of two male mice was not modified in any group; however, when they were paired with females, Glu-CB1 À/À mice showed reduced interaction. Also, exploration of the male stimulus subject in the three-chamber social investigation test was almost unaffected. The situation was completely different when a female was used as the stimulus subject. In this case, Glu-CB1 À/À mice showed reduced interest in the social stimulus, mimicking the phenotype of CB1 À/À or WT mice treated with SR141716A. GABA-CB1 À/À mice showed the opposite phenotype, by spending more time investigating the social stimulus. In conclusion, we provide evidence that CB1 receptors specifically modulate the social investigation of female mice in a neuronal subtype-specific manner.
A large body of evidence corroborates the notion that deficiencies of serotonergic system are lik... more A large body of evidence corroborates the notion that deficiencies of serotonergic system are likely involved in the pathogenesis of both depression and anxiety. Activation of β 3 adrenoceptors has been shown to increase brain tryptophan content suggesting an elevation of brain serotonin (5HT) synthesis. SR58611A is a selective β 3 adrenergic agent possessing a profile of antidepressant activity in routine rodents' experimental models of depression. The present study was undertaken to evaluate in rodents the antidepressant properties of SR58611A and to assess its putative anxiolytic value in experimental models of depression and anxiety. Compared to the control group, SR58611A (0.1, 1, 5 or 10 mg/kg) caused a dose-dependent reduction in immobility of Wistar male rats in the forced swim test. The maximum dose appeared to be equivalent to an effective dose of clomipramine (50 mg/kg). In addition, acute injection of SR58611A induced in rats a dose-dependent decrease in grooming response to a novel environment (novelty-induced grooming test). For any dose, the effect was lower than that of diazepam (1 mg/kg). Chronic treatment with SR58611A resulted also in an increased social interaction time in the social interaction test without affecting motor activity of rats. Furthermore, similarly to diazepam a chronic treatment with the highest doses of SR58611A was followed by increased exploratory behavior in Swiss male mice exposed to the elevated plus maze test. These effects are mediated by β 3 adrenoceptors since i.p. pretreatment with the selective β 3 adrenoceptor antagonist SR59230A (5 mg/kg) blocked the effects of SR58611A. Finally, also the 5HT antagonist methysergide (2 mg/kg) prevented the antidepressant and anxiolytic-like activity of SR58611A indicating that 5HT transmission is strictly involved in its action.
Abnormalities in social behavior are found in almost all psychiatric disorders, such as anxiety, ... more Abnormalities in social behavior are found in almost all psychiatric disorders, such as anxiety, depression, autism, and schizophrenia. Thus, comprehension of the neurobiological basis of social interaction is important for a better understanding of numerous pathologies and improved treatments. Several findings have suggested that an alteration of cannabinoid receptor type 1 (CB1) receptor function could be involved in the pathophysiology of such disorders. However, the role of CB1 receptors is still unclear, and their localisation on different neuronal subpopulations may produce distinct outcomes. To dissect the role of CB1 receptors in different neuronal populations, we used male knockout mice and their respective control littermates [total deletion (CB1 À/À ); specific deletion on cortical glutamatergic neurons (Glu-CB1 À/À ) or on GABAergic interneurons (GABA-CB1 À/À ), and wild-type (WT) mice treated with the CB1 antagonist/inverse agonist SR141716A (3 mg/kg). Mice were required to perform different social tasksdirect social interaction and social investigation. Direct interaction of two male mice was not modified in any group; however, when they were paired with females, Glu-CB1 À/À mice showed reduced interaction. Also, exploration of the male stimulus subject in the three-chamber social investigation test was almost unaffected. The situation was completely different when a female was used as the stimulus subject. In this case, Glu-CB1 À/À mice showed reduced interest in the social stimulus, mimicking the phenotype of CB1 À/À or WT mice treated with SR141716A. GABA-CB1 À/À mice showed the opposite phenotype, by spending more time investigating the social stimulus. In conclusion, we provide evidence that CB1 receptors specifically modulate the social investigation of female mice in a neuronal subtype-specific manner.
Cannabinoid Modulation of Emotion, Memory, and Motivation, 2015
The endogenous cannabinoid system (ECS) works as pro-homeostatic and pleiotropic signaling system... more The endogenous cannabinoid system (ECS) works as pro-homeostatic and pleiotropic signaling system activated in a time-and tissue-specific way during physiological conditions, which include cognitive, emotional and motivational processes. It is composed of two G protein-coupled receptors (the cannabinoid receptors types 1 and 2 [CB1 and CB2] for marijuana's psychoactive ingredient Δ9-tetrahydrocannabinol [Δ9-THC]), their endogenous small lipid ligands (anandamide [AEA] and 2-arachidonoylglycerol [2-AG], also known as endocannabinoids), and the proteins for endocannabinoid biosynthesis and deactivation. Data from preclinical and clinical studies have reported that a hypofunction of the endocannabinoid signaling could induce a depressive-like phenotype; consequently, enhancement of endocannabinoid signaling could be a novel therapeutic avenue for the treatment of depression. To this aim there have been proposed cannabinoid receptor agonists or synthetic molecules that inhibit endocannabinoid degradation. The latter ones do not induce the psychotropic side effects by direct CB1 receptor activation, but rather elicit antidepressant-like effects by enhancing the monoaminergic neurotransmission, promoting hippocampal neurogenesis and normalizing the hyperactivity of hypothalamic-pituitary-adrenal axis, similarly as the standard antidepressants. The dysfunction of elements belonging to the ECS and the possible therapeutic use of endocannabinoid deactivation inhibitors and phytocannabinoids in depression is discussed in this chapter.
Ruda-Kucerova J, Amchova P, Babinska Z, Dusek L, Micale V and Sulcova A (2015) Sex differences in... more Ruda-Kucerova J, Amchova P, Babinska Z, Dusek L, Micale V and Sulcova A (2015) Sex differences in the reinstatement of methamphetamine seeking after forced abstinence in Preventing relapse to drug abuse is one of the struggles faced by clinicians in order to treat patients with substance use disorders (DSM-5). There is a large body of clinical evidence suggesting differential characteristics of the disorder in men and women, which is in line with preclinical findings as well. The aim of this study was to assess differences in relapse-like behavior in methamphetamine (METH) seeking after a period of forced abstinence, which simulates the real clinical situation very well. Findings from such study might add new insights in gender differences in relapse mechanisms to previous studies, which employ a classical drug or cue-induced reinstatement procedure following the extinction training. Adult male and female Sprague-Dawley rats were used in IV self-administration procedure conducted in operant boxes using nose-poke operandi (Coulborn Instruments, USA). Active nose-poke resulted in activation of the infusion pump to deliver one intravenous infusion of METH (0.08 mg/kg). After baseline drug intake was established (maintenance phase), a period of forced abstinence was initiated and rats were kept singly in their home cages for 14 days. Finally, one reinstatement session in operant boxes was conducted. Females were found to self-administer significantly lower dose of METH. The relapse rate was assessed as a number of active nosepokes during the reinstatement session, expressed as a percentage of active nose-poking during the maintenance phase. Females displayed approximately 300% of active nosepokes compared to 50% in males. This indicates higher vulnerability to relapse of METH seeking behavior in female rats. This effect was detected in all females, independently of current phase of their estrous cycle. Therefore, this paradigm using operant drug self-administration and reinstatement of drug-seeking after forced abstinence model can be used for preclinical screening for potential new anti-relapse medications specific for women.
The contribution of two major endocannabinoids, 2-arachidonoylglycerol (2-AG) and anandamide (AEA... more The contribution of two major endocannabinoids, 2-arachidonoylglycerol (2-AG) and anandamide (AEA), in the regulation of fear expression is still unknown. We analyzed the role of different players of the endocannabinoid system on the expression of a strong auditory-cued fear memory in male mice by pharmacological means. The cannabinoid receptor type 1 (CB1) antagonist SR141716 (3 mg/kg) caused an increase in conditioned freezing upon repeated tone presentation on three consecutive days. The cannabinoid receptor type 2 (CB2) antagonist AM630 (3 mg/kg), in contrast, had opposite effects during the first tone presentation, with no effects of the transient receptor potential vanilloid receptor type 1 (TRPV1) antagonist SB366791 (1 and 3 mg/kg). Administration of the CB2 agonist JWH133 (3 mg/kg) failed to affect the acute freezing response, whereas the CB1 agonist CP55,940 (50 μg/kg) augmented it. The endocannabinoid uptake inhibitor AM404 (3 mg/kg), but not VDM11 (3 mg/kg), reduced the ...
The cannabinoid CB1 and CB2 receptors, the endogenous endocannabinoid (EC) ligands anandamide (AE... more The cannabinoid CB1 and CB2 receptors, the endogenous endocannabinoid (EC) ligands anandamide (AEA) and 2-arachidonylethanolamide, and the degradative enzymes fatty acid amide hydrolase (FAAH) and monoglyceride lipase (ML) are key elements of the EC system implicated in different physiological functions including cognition, motor activity and immune responses. Thus, both the possible neuroprotective role of ECs and their modulating action on neurotransmitter systems affected in several neurodegenerative diseases such as Alzheimer's disease (AD), Huntington's disease (HD) and multiple sclerosis (MS) are currently under investigation. Accumulating data show an unbalance in the EC system (i.e. decrease of neuronal cannabinoid CB1 receptors, increase of glial cannabinoid CB2 receptors and over-expression of FAAH in astrocytes) in experimental models of AD as well as in post-mortem brain tissue of AD patients, suggesting its possible role in inflammatory processes and in neuroprotection. However, the mechanisms of the EC modulation of immune response are not fully understood.
Increasing evidence suggests a close relationship between the endocannabinoid system and schizoph... more Increasing evidence suggests a close relationship between the endocannabinoid system and schizophrenia. The endocannabinoid system comprises of two G protein-coupled receptors (the cannabinoid receptors 1 and 2 [CB1 and CB2] for marijuana's psychoactive principle 9 -tetrahydrocannabinol), their endogenous small lipid ligands (namely anandamide [AEA] and 2-arachidonoylglycerol [2-AG], also known as endocannabinoids), and proteins for endocannabinoid biosynthesis and degradation. It has been suggested to be a pro-homeostatic and pleiotropic signalling system activated in a time-and tissue-specific manner during pathophysiological conditions. In the brain, activation of this system impacts the release of numerous neurotransmitters in various systems and cytokines from glial cells. Hence, the endocannabinoid system is strongly involved in neuropsychiatric disorders, such as schizophrenia. Therefore, adolescence use of Cannabis may alter the endocannabinoid signalling and pose a potential environmental risk to develop psychosis. Consistently, preclinical and clinical studies have found a dysregulation in the endocannabinoid system such as changed expression of CB1 and CB2 receptors or altered levels of AEA and 2-AG . Thus, due to the partial efficacy of actual antipsychotics, compounds which modulate this system may provide a novel therapeutic target for the treatment of schizophrenia. The present article reviews current available knowledge on herbal, synthetic and endogenous cannabinoids with respect to the modulation of schizophrenic symptomatology. Furthermore, this review will be highlighting the therapeutic potential of cannabinoid-related compounds and presenting some promising patents targeting potential treatment options for schizophrenia.
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