Units were recorded extracellularly in the medullary reticular formation of chloralose-anesthetiz... more Units were recorded extracellularly in the medullary reticular formation of chloralose-anesthetized cats during electrical stimulation of the basal ganglia (BG). Stimulating portions of the BG (caudate nucleus, entopeduncular nucleus, substantia nigra) evoked unit responses in a considerable proportion of these neurons. The majority of reticular cells that were affected by the BG were also receptive to somatic sensory inputs from the face. These units' sensory properties were influenced by BG stimulation. Cells exclusively responsive to either BG or facial inputs were uncommon. The areas of the reticular formation affected by the BG give rise to portions of the reticulospinal tracts and thereby afford the BG access to the final common path.
This investigation assessed the influences of trigeminal primary sensory afferents upon caudate n... more This investigation assessed the influences of trigeminal primary sensory afferents upon caudate neuronal activity in locally anesthetized and chloralose anesthetized cats. Afferents from jaw elevator stretch receptors were stimulated via electrodes in the trigeminal mesencephalic nucleus (Mes 5). Afferents from dental and periodontal receptors were stimulated via electrodes in the inferior dental nerve (IDN). Low intensity electrical stimulation of either locus evoked caudate neuronal responses with Mes 5 being more effective. Higher intensity stimulation of IDN in chloralose anesthetized cats was used to determine if thresholds of trigeminal evoked caudate responses corresponded to thresholds of particular fiber groups in the sensory afferent. In all tested units, neuronal responses were only evoked when stimulation was suprathreshold for both A beta and A delta fibers. These data were discussed in relation to processing of oropharyngeal sensory information within the basal ganglia. Possible implications for bucco-lingual dyskinesias were noted.
ANTAGONIST action at dopamine D2 receptors appears to explain many, but not all of the effects of... more ANTAGONIST action at dopamine D2 receptors appears to explain many, but not all of the effects of antipsychotic drugs. Because of the interactions of dopamine with glutamate, and the implication of the latter in the etiology of schizophrenia, possible effects of antipsychotic drugs on glutamate receptors were assessed in the present experiments. These studies showed that, at clinically relevant concentrations, the conventional neuroleptic haloperidol and the atypical antipsychotic clozapine had potent augmenting influences on the NMDA receptor. These data suggest that unique action at glutamate receptors may contribute to antipsychotic efficacy and emphasize the potential importance of glutamatergic dysfunction in the etiology of schizophrenia.
Journal of Toxicology and Environmental Health, 1990
Clinical signs of delayed neuropathy were induced in adult white leghorn chickens given the organ... more Clinical signs of delayed neuropathy were induced in adult white leghorn chickens given the organophosphorus ester phenyl saligenin phosphate (PSP, 2.5 mg/kg im) 22-24 d before assessment of nerve conduction parameters. Damage to the myelinated sensory portion of the sciatic nerve was indicated by abnormal compound action potentials in treated chickens. In particular, the amplitude of the A beta response was markedly reduced. In addition, the A beta fibers did not respond normally to increasing stimulation intensity. These parameters were more like controls in chickens that had been given PSP and 30 ppm corticosterone for 11 d, beginning 1 d before PSP administration. These studies indicated that nerve conduction parameters could distinguish peripheral nerve damage in chickens given PSP and improvement could be noted in chickens treated with corticosterone.
... Psychol. 70: 116-125, 1970. 2. Slangen, JL and J, AWN Weijnen. The reinforcing effect of elec... more ... Psychol. 70: 116-125, 1970. 2. Slangen, JL and J, AWN Weijnen. The reinforcing effect of electrical stimulation of the tongue in thirsty rats. Phvsiol. ... 116–125. 2. JL Slangen and JAWN Weijnen, The reinforcing effect of electrical stimulation of the tongue in thirsty rats. Physiol. ...
The mechanisms of clozapine's unusual actions were investigated in anesthetized rats. Sen... more The mechanisms of clozapine's unusual actions were investigated in anesthetized rats. Sensory field potentials were recorded in the nucleus accumbens, striatum and somatosensory cortex. Both haloperidol and clozapine suppressed responses in the striatum and accumbens. Clozapine's but not haloperidol's subcortical actions were unaffected by dopamine depletion. In addition, the cortical effects of the two drugs differed. These data indicate that clozapine has non-dopaminergic activity but no particular specificity for limbic basal ganglia structures. While it is known that clozapine acts as a serotonergic and cholinergic antagonist, several considerations suggest that action on still another transmitter system, possibly glutamate, needs to be investigated.
Tardive dyskinesia is a disabling movement disorder, caused by antipsychotic medications, that oc... more Tardive dyskinesia is a disabling movement disorder, caused by antipsychotic medications, that occurs frequently and is not responsive to treatment. It is not known how the brain damage underlying tardive dyskinesia produces abnormal movement. We propose that altered sensory flow to motor systems results in this syndrome. Verification of such a mechanism could lead to early detection and improved treatment of tardive dyskinesia.
Electrical stimulation of the substantia nigra in cats elicits jaw movements. A variety of tests ... more Electrical stimulation of the substantia nigra in cats elicits jaw movements. A variety of tests were performed to assess the contribution of current spread to this phenomenon. The results of these tests strongly suggest that stimulation-evoked movements are not due to activation of the substantia nigra but rather are the result of current spread to adjacent structures.
Units were recorded extracellularly in the medullary reticular formation of chloralose-anesthetiz... more Units were recorded extracellularly in the medullary reticular formation of chloralose-anesthetized cats during electrical stimulation of the basal ganglia (BG). Stimulating portions of the BG (caudate nucleus, entopeduncular nucleus, substantia nigra) evoked unit responses in a considerable proportion of these neurons. The majority of reticular cells that were affected by the BG were also receptive to somatic sensory inputs from the face. These units' sensory properties were influenced by BG stimulation. Cells exclusively responsive to either BG or facial inputs were uncommon. The areas of the reticular formation affected by the BG give rise to portions of the reticulospinal tracts and thereby afford the BG access to the final common path.
This investigation assessed the influences of trigeminal primary sensory afferents upon caudate n... more This investigation assessed the influences of trigeminal primary sensory afferents upon caudate neuronal activity in locally anesthetized and chloralose anesthetized cats. Afferents from jaw elevator stretch receptors were stimulated via electrodes in the trigeminal mesencephalic nucleus (Mes 5). Afferents from dental and periodontal receptors were stimulated via electrodes in the inferior dental nerve (IDN). Low intensity electrical stimulation of either locus evoked caudate neuronal responses with Mes 5 being more effective. Higher intensity stimulation of IDN in chloralose anesthetized cats was used to determine if thresholds of trigeminal evoked caudate responses corresponded to thresholds of particular fiber groups in the sensory afferent. In all tested units, neuronal responses were only evoked when stimulation was suprathreshold for both A beta and A delta fibers. These data were discussed in relation to processing of oropharyngeal sensory information within the basal ganglia. Possible implications for bucco-lingual dyskinesias were noted.
ANTAGONIST action at dopamine D2 receptors appears to explain many, but not all of the effects of... more ANTAGONIST action at dopamine D2 receptors appears to explain many, but not all of the effects of antipsychotic drugs. Because of the interactions of dopamine with glutamate, and the implication of the latter in the etiology of schizophrenia, possible effects of antipsychotic drugs on glutamate receptors were assessed in the present experiments. These studies showed that, at clinically relevant concentrations, the conventional neuroleptic haloperidol and the atypical antipsychotic clozapine had potent augmenting influences on the NMDA receptor. These data suggest that unique action at glutamate receptors may contribute to antipsychotic efficacy and emphasize the potential importance of glutamatergic dysfunction in the etiology of schizophrenia.
Journal of Toxicology and Environmental Health, 1990
Clinical signs of delayed neuropathy were induced in adult white leghorn chickens given the organ... more Clinical signs of delayed neuropathy were induced in adult white leghorn chickens given the organophosphorus ester phenyl saligenin phosphate (PSP, 2.5 mg/kg im) 22-24 d before assessment of nerve conduction parameters. Damage to the myelinated sensory portion of the sciatic nerve was indicated by abnormal compound action potentials in treated chickens. In particular, the amplitude of the A beta response was markedly reduced. In addition, the A beta fibers did not respond normally to increasing stimulation intensity. These parameters were more like controls in chickens that had been given PSP and 30 ppm corticosterone for 11 d, beginning 1 d before PSP administration. These studies indicated that nerve conduction parameters could distinguish peripheral nerve damage in chickens given PSP and improvement could be noted in chickens treated with corticosterone.
... Psychol. 70: 116-125, 1970. 2. Slangen, JL and J, AWN Weijnen. The reinforcing effect of elec... more ... Psychol. 70: 116-125, 1970. 2. Slangen, JL and J, AWN Weijnen. The reinforcing effect of electrical stimulation of the tongue in thirsty rats. Phvsiol. ... 116–125. 2. JL Slangen and JAWN Weijnen, The reinforcing effect of electrical stimulation of the tongue in thirsty rats. Physiol. ...
The mechanisms of clozapine's unusual actions were investigated in anesthetized rats. Sen... more The mechanisms of clozapine's unusual actions were investigated in anesthetized rats. Sensory field potentials were recorded in the nucleus accumbens, striatum and somatosensory cortex. Both haloperidol and clozapine suppressed responses in the striatum and accumbens. Clozapine's but not haloperidol's subcortical actions were unaffected by dopamine depletion. In addition, the cortical effects of the two drugs differed. These data indicate that clozapine has non-dopaminergic activity but no particular specificity for limbic basal ganglia structures. While it is known that clozapine acts as a serotonergic and cholinergic antagonist, several considerations suggest that action on still another transmitter system, possibly glutamate, needs to be investigated.
Tardive dyskinesia is a disabling movement disorder, caused by antipsychotic medications, that oc... more Tardive dyskinesia is a disabling movement disorder, caused by antipsychotic medications, that occurs frequently and is not responsive to treatment. It is not known how the brain damage underlying tardive dyskinesia produces abnormal movement. We propose that altered sensory flow to motor systems results in this syndrome. Verification of such a mechanism could lead to early detection and improved treatment of tardive dyskinesia.
Electrical stimulation of the substantia nigra in cats elicits jaw movements. A variety of tests ... more Electrical stimulation of the substantia nigra in cats elicits jaw movements. A variety of tests were performed to assess the contribution of current spread to this phenomenon. The results of these tests strongly suggest that stimulation-evoked movements are not due to activation of the substantia nigra but rather are the result of current spread to adjacent structures.
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