Jorge Mpodozis
Universidad de Chile, Departamento de Biología, Faculty Member
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Research Interests: Neuroscience, Biology, Medicine, Amygdala, Superior Colliculus, and 3 moreDDC, Stimulation, and Nucleus
The word perception is usually heard as connoting an operation of grasping an external reality through the process of receiving information from it. This, however, is constitutively impossible because living systems are dynamic structure... more
The word perception is usually heard as connoting an operation of grasping an external reality through the process of receiving information from it. This, however, is constitutively impossible because living systems are dynamic structure determined systems, and everything happens in them determined at every instant by their structure. This means that the medium cannot specify what happens in a living system, and that it can only trigger in it structural changes determined in its structure. As a result a living system constitutively always operates in structural congruence with the medium, and exists as such only as long as this structural congruence (adaptation) is conserved; otherwise it desintegrates. In these circumstances, the phenomenon connoted by the word perception consists in the association, by the observer, of the behavioral regularities that he or she distinguishes in the observed organism with the conditions of the medium that he or she sees triggering them. The observer uses such behavioral regularities to characterize perceptual objects. This applies to all living systems including the observer. The explanation of perception in the context of the structural determinism of living systems invalidates any attempt to account for the phenomenon of cognition (including language) with notions that entail the denotation or connotation of a domain of reality independent of the distinctions of the observer.
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Living beings are autopoietic systems with highly context‐dependent structural dynamics and interactions, that determine whether a disturbance in the genotype or environment will lead or not to phenotypic change. The concept of epigenesis... more
Living beings are autopoietic systems with highly context‐dependent structural dynamics and interactions, that determine whether a disturbance in the genotype or environment will lead or not to phenotypic change. The concept of epigenesis entails how a change in the phenotype may not correspond to a change in the structure of an earlier developmental stage, including the genome. Disturbances of embryonic structure may fail to change the phenotype, as in regulated development, or when different genotypes are associated to a single phenotype. Likewise, the same genotype or early embryonic structure may develop different phenotypes, as in phenotypic plasticity. Disturbances that fail to trigger phenotypic change are considered neutral, but even so, they can alter unexpressed developmental potential. Here, we present conceptual diagrams of the “epigenic field”: similar to Waddington's epigenetic landscapes, but including the ontogenic niche (organism/environment interactional dynami...
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A defining feature of the amniote tecto‐fugal visual pathway is a massive bilateral projection to the thalamus originating from a distinct neuronal population, tectal ganglion cells (TGCs), of the optic tectum/superior colliculus... more
A defining feature of the amniote tecto‐fugal visual pathway is a massive bilateral projection to the thalamus originating from a distinct neuronal population, tectal ganglion cells (TGCs), of the optic tectum/superior colliculus (TeO/SC). In sauropsids, the thalamic target of the tecto‐fugal pathway is the nucleus rotundus thalami (Rt). TGCs axons collateralize en route to Rt to target the nucleus pretectalis principalis (PT), which in turn gives rise to bilateral projection to the TeO. In rodents, the thalamic target of these TGCs afferents is the caudal division of the pulvinar complex (PulC). No pretectal structures in receipt of TGC collaterals have been described in this group. However, Baldwin et al. (Journal of Comparative Neurology, 2011;519(6):1071–1094) reported in the squirrel a feedback projection from the PulC to the SC. Pulvino‐tectal (Pul‐T) cells lie at the caudal pole of the PulC, intermingled with the axonal terminals of TGCs. Here, by performing a combination of ...
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To what extent can the mammalian visual system be shaped by visual behavior? Here we analyze the shape of the visual fields, the densities and distribution of cells in the retinal ganglion-cell layer and the organization of the visual... more
To what extent can the mammalian visual system be shaped by visual behavior? Here we analyze the shape of the visual fields, the densities and distribution of cells in the retinal ganglion-cell layer and the organization of the visual projections in two species of facultative non-strictly subterranean rodents, Spalacopus cyanus and Ctenomys talarum, aiming to compare these traits with those of phylogenetically closely related species possessing contrasting diurnal/nocturnal visual habits. S. cyanus shows a definite zone of frontal binocular overlap and a corresponding area centralis, but a highly reduced amount of ipsilateral retinal projections. The situation in C. talarum is more extreme as it lacks of a fronto-ventral area of binocular superposition, has no recognizable area centralis and shows no ipsilateral retinal projections except to the suprachiasmatic nucleus. In both species, the extension of the monocular visual field and of the dorsal region of binocular overlap as well...
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In this article we propose that the mechanism that gave rise to the diversity of living systems that we find today, as well as to the biosphere as coherent system of interrelated autonomous living systems, is natural drift. And we also... more
In this article we propose that the mechanism that gave rise to the diversity of living systems that we find today, as well as to the biosphere as coherent system of interrelated autonomous living systems, is natural drift. And we also propose that that which we biologists connote with the expression natural selection is a consequence of the history of the constitution of the biosphere through natural drift, and not the mechanism that generates that history. Moreover, we do this by proposing: a) that the history of living systems on earth is the history of the arising, conservation, and diversification of lineages through reproduction, and not of populations; b) that biological reproduction is a systemic process of conservation of a particular ontogenic-phenotype/ontogenic- niche relation, and not a genetic process of conservation of some genetic constitution; c) that a lineage arises in the systemic reproductive conservation of an ontogenic-phenotype/ontogenic-niche relation, and n...
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Research Interests: Neuroscience, Spatial Attention, Female, Animals, Male, and 15 moreThe, Superior Colliculus, Columbidae, Cholinergic Systems, Action Potentials, Midbrain, Tectum, Nucleus, Neurosciences, Pigeon, Optic tectum, photic stimulation, Psychology and Cognitive Sciences, Medical and Health Sciences, and Visual Pathways
The dorsal ventricular ridge (DVR), which is the largest component of the avian pallium, contains discrete partitions receiving tectovisual, auditory, and trigeminal ascending projections. Recent studies have shown that the auditory and... more
The dorsal ventricular ridge (DVR), which is the largest component of the avian pallium, contains discrete partitions receiving tectovisual, auditory, and trigeminal ascending projections. Recent studies have shown that the auditory and the tectovisual regions can be regarded as complexes composed of three highly interconnected layers: an internal senso‐recipient one, an intermediate afferent/efferent one, and a more external re‐entrant one. Cells located in homotopic positions in each of these layers are reciprocally linked by an interlaminar loop of axonal processes, forming columnar‐like local circuits. Whether this type of organization also extends to the trigemino‐recipient DVR is, at present, not known. This question is of interest, since afferents forming this sensory pathway, exceptional among amniotes, are not thalamic but rhombencephalic in origin. We investigated this question by placing minute injections of neural tracers into selected locations of vital slices of the chicken telencephalon. We found that neurons of the trigemino‐recipient nucleus basorostralis pallii (Bas) establish reciprocal, columnar and homotopical projections with cells located in the overlying ventral mesopallium (MV). “Column‐forming” axons originated in B and MV terminate also in the intermediate strip, the fronto‐trigeminal nidopallium (NFT), in a restricted manner. We also found that the NFT and an internal partition of B originate substantial, coarse‐topographic projections to the underlying portion of the lateral striatum. We conclude that all sensory areas of the DVR are organized according to a common neuroarchitectonic motif, which bears a striking resemblance to that of the radial/laminar intrinsic circuits of the sensory cortices of mammals.
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The origin of the human alpha rhythm has been a matter of debate since Lord Adrian attributed it to synchronous neural populations in the occipital cortex. While some authors have pointed out the Gaussian characteristics of the alpha... more
The origin of the human alpha rhythm has been a matter of debate since Lord Adrian attributed it to synchronous neural populations in the occipital cortex. While some authors have pointed out the Gaussian characteristics of the alpha rhythm, their results have been repeatedly disregarded in favor of Adrian’s interpretation; even though the first EEG Gaussianity reports can be traced back to the origins of EEG. Here we revisit this problem using the envelope analysis — a method that relies on the fact that the coefficient of variation of the envelope (CVE) for continuous-time zero-mean Gaussian white noise (as well as for any filtered sub-band) is equal to , thus making the CVE a fingerprint for Gaussianity. As a consequence, any significant deviation from Gaussianity is linked to synchronous neural dynamics. Low-CVE signals come from phase-locking dynamics, while mid-CVE signals constitute Gaussian noise. High-CVE signals have been linked to unsteady dynamics in populations of nonli...
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In mammals, the accessory olfactory or vomeronasal system exhibits a wide variety of anatomical arrangements. In caviomorph rodents, the accessory olfactory bulb (AOB) exhibits a dichotomic conformation, in which two subdomains, the... more
In mammals, the accessory olfactory or vomeronasal system exhibits a wide variety of anatomical arrangements. In caviomorph rodents, the accessory olfactory bulb (AOB) exhibits a dichotomic conformation, in which two subdomains, the anterior (aAOB) and the posterior (pAOB), can be readily distinguished. Interestingly, different species of this group exhibit bias of different sign between the AOB subdomains (aAOB larger than pAOB or vice versa). Such species‐specific biases have been related with contrasting differences in the habitat of the different species (e.g. arid vs. humid environments). Aiming to deepen these observations, we performed a morphometric comparison of the AOB subdomains between two sister species of octodontid rodents, Octodon lunatus and Octodon degus. These species are interesting for comparative purposes, as they inhabit similar landscapes but exhibit contrasting social habits. Previous reports have shown that O. degus, a highly social species, exhibits a greatly asymmetric AOB, in which the aAOB has twice the size of the pAOB and features more and larger glomeruli in its glomerular layer (GL). We found that the same as in O. degus, the far less social O. lunatus also exhibits a bias, albeit less pronounced, to a larger aAOB. In both species, this bias was also evident for the mitral/tufted cells number. But unlike in O. degus, in O. lunatus this bias was not present at the GL. In comparison with O. degus, in O. lunatus the aAOB GL was significantly reduced in volume, while the pAOB GL displayed a similar volume. We conclude that these sister species exhibit a very sharp difference in the anatomical conformation of the AOB, namely, the relative size of the GL of the aAOB subdomain, which is larger in O. degus than in O. lunatus. We discuss these results in the context of the differences in the lifestyle of these species, highlighting the differences in social behaviour as a possible factor driving to distinct AOB morphometries.
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SUMMARY It has been argued that trichromatic bees with photoreceptor spectral sensitivity peaks in the ultraviolet (UV), blue and green areas of the spectrum are blind to long wavelengths (red to humans). South American temperate forests... more
SUMMARY It has been argued that trichromatic bees with photoreceptor spectral sensitivity peaks in the ultraviolet (UV), blue and green areas of the spectrum are blind to long wavelengths (red to humans). South American temperate forests (SATF) contain a large number of human red-looking flowers that are reported to be visited by the bumblebee Bombus dahlbomii. In the present study, B. dahlbomii's spectral sensitivity was measured through electroretinogram (ERG) recordings. No extended sensitivity to long wavelengths was found in B. dahlbomii. The spectral reflectance curves from eight plant species with red flowers were measured. The color loci occupied by these flowers in the bee color space was evaluated using the receptor noise-limited model. Four of the plant species have pure red flowers with low levels of chromatic contrast but high levels of negative L-receptor contrast. Finally, training experiments were performed in order to assess the role of achromatic cues in the de...
Research Interests: Animal Behavior, Biology, Biological Sciences, Bees, Color, and 15 moreUltraviolet, Animals, Color Vision, Flowers, South America, Spectrum, Color Space, Bee, Spectral Reflectance, Plant species, Spectral Sensitivity, Temperate Forest, Experimental Biology, Electroretinogram, and Medical and Health Sciences
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Neurons can change their classical neurotransmitters during ontogeny, sometimes going through stages of dual release. Here, we explored the development of the neurotransmitter identity of neurons of the avian nucleus isthmi... more
Neurons can change their classical neurotransmitters during ontogeny, sometimes going through stages of dual release. Here, we explored the development of the neurotransmitter identity of neurons of the avian nucleus isthmi parvocellularis (Ipc), whose axon terminals are retinotopically arranged in the optic tectum (TeO) and exert a focal gating effect upon the ascending transmission of retinal inputs. Although cholinergic and glutamatergic markers are both found in Ipc neurons and terminals of adult pigeons and chicks, the mRNA expression of the acetylcholine vesicular transporter, VAChT, is weak or absent. To explore how the Ipc neurotransmitter identity is established during ontogeny, we analyzed the expression of mRNAs coding for cholinergic (ChAT, VAChT, and CHT) and glutamatergic (VGluT2 and VGluT3) markers in chick embryos at different developmental stages. We found that between E12 and E18, Ipc neurons expressed all cholinergic mRNAs, and also VGluT2 mRNA; however, from E16 through posthatch stages, VAChT mRNA expression was specifically diminished. Our ex-vivo deposits of tracer crystals and intracellular filling experiments revealed that Ipc axons exhibit a mature paintbrush morphology late in development, experiencing marked morphological transformations during the period of presumptive dual vesicular transmitter release. Additionally, although ChAT protein immunoassays increasingly label the growing Ipc axon, this labeling was consistently restricted to sparse portions of the terminal branches. Combined, these results suggest that the synthesis of glutamate and acetylcholine, and their vesicular release, are complexly linked to the developmental processes of branching, growing and remodeling of these unique axons.
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O surgimento do sistema imune na filogênese dos vertebrados mandibulados com sua vasta coleção de receptoreslinfocitários expressos de forma clonal é usualmente visto como um processo otimizado para a defesa do organismo.Há uma clara... more
O surgimento do sistema imune na filogênese dos vertebrados mandibulados com sua vasta coleção de receptoreslinfocitários expressos de forma clonal é usualmente visto como um processo otimizado para a defesa do organismo.Há uma clara associação entre o neodarwinismo, a visão dominante na Biologia atual e a descrição usual da atividadeimunológica, conhecida como imunidade adaptativa. Neste texto, sugerimos que toda uma nova abordagem à origem dossistemas vivos, denominada por Maturana e Mpodozis deriva filogênica natural, aplicada à imunologia, pode substituir aexplicação neodarwinista sobre a origem da atividade imunológica. Além disso, pelo emprego dos conceitos de tímpanos (spandrels) e de exaptação, criados por Gould e colaboradores, revemos dados da imunologia comparada e afirmamos que o sistema imune não se formou como um sistema otimizado para a defesa do organismo, mas pode ser visto como um tímpano (spandrel), uma consequência de processos que originalmente não estavam relac...
Nocturnal animals that rely on their visual system for foraging, mating, and navigation usually exhibit specific traits associated with living in scotopic conditions. Most nocturnal birds have several visual specializations, such as... more
Nocturnal animals that rely on their visual system for foraging, mating, and navigation usually exhibit specific traits associated with living in scotopic conditions. Most nocturnal birds have several visual specializations, such as enlarged eyes and an increased orbital convergence. However, the actual role of binocular vision in nocturnal foraging is still debated. Nightjars (Aves: Caprimulgidae) are predators that actively pursue and capture flying insects in crepuscular and nocturnal environments, mainly using a conspicuous “sit-and-wait” tactic on which pursuit begins with an insect flying over the bird that sits on the ground. In this study, we describe the visual system of the band-winged nightjar (Systellura longirostris), with emphasis on anatomical features previously described as relevant for nocturnal birds. Orbit convergence, determined by 3D scanning of the skull, was 73.28°. The visual field, determined by ophthalmoscopic reflex, exhibits an area of maximum binocular ...
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Navigational and social challenges due to habitat conditions and sociality are known to influence dentate gyrus (DG) morphology, yet the relative importance of these factors remains unclear. Thus, we studied three natural populations of... more
Navigational and social challenges due to habitat conditions and sociality are known to influence dentate gyrus (DG) morphology, yet the relative importance of these factors remains unclear. Thus, we studied three natural populations of O. lunatus (Los Molles) and Octodon degus (El Salitre and Rinconada), two caviomorph species that differ in the extent of sociality and with contrasting vegetation cover of habitat used. The brains and DG of male and female breeding degus with simultaneous information on their physical and social environments were examined. The extent of sociality was quantified from total group size and range area overlap. O. degus at El Salitre was more social than at Rinconada and than O. lunatus from Los Molles. The use of transects to quantify cover of vegetation (and other physical objects in the habitat) and measures of the spatial behavior of animals indicated animal navigation based on unique cues or global landmarks is more cognitively challenging to O. lun...
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The avian pretectal and ventrothalamic nuclei, encompassing the griseum tectale (GT), lentiformis mesencephali (LM) and geniculatus lateralis pars ventralis (GLv), are prominent retinorecipient structures related to optic flow operations... more
The avian pretectal and ventrothalamic nuclei, encompassing the griseum tectale (GT), lentiformis mesencephali (LM) and geniculatus lateralis pars ventralis (GLv), are prominent retinorecipient structures related to optic flow operations and visuomotor control. Hence, a close coordination of these neural circuits is to be expected. Yet the connectivity among these nuclei is known poorly. Here, using intracellular labeling and in situ hybridization, we investigated the detailed morphology, connectivity and neurochemical identity of neurons in these nuclei. Two different cell types exist in the GT: one that generates an axonal projection to optic tectum (TeO), LM, GLv, and n. intercalatus thalami (ICT), and a second population that only projects to the LM and GLv. In situ hybridization revealed that most neurons in the GT express the vesicular glutamate transporter (VGluT2) mRNA, indicating a glutamatergic identity. In the LM three morphological cell types were defined, two of which project axons towards dorsal targets. The LM neurons showed strong VGluT2 expression. Finally, the cells located in the GLv project to the TeO, LM, GT, n. principalis precommisuralis (PPC) and ICT. All neurons in the GLv showed strong expression of the vesicular inhibitory amino acid transporter (VIAAT) mRNA, suggesting a GABAergic identity. Our results show that the pretectal and ventrothalamic nuclei are highly interconnected, especially by glutamatergic and GABAergic neurons from the GT and GLv, respectively. This complex morphology and connectivity might be required to organize orienting visuomotor behaviors and coordinate the specific optic flow patterns that they induce. This article is protected by copyright. All rights reserved.
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Vocal learning and other experience-dependent processes play a crucial role in the emergence of complex social systems. Among birds, Songbirds (Order Passeriformes) have been the canonical model for the study of vocal learning. Parrots... more
Vocal learning and other experience-dependent processes play a crucial role in the emergence of complex social systems. Among birds, Songbirds (Order Passeriformes) have been the canonical model for the study of vocal learning. Parrots (Order Psittaciformes) have received surprisingly less attention, despite the fact that they are versatile vocal learners and display a repertoire of vocal communicative behaviors substantially more diverse than that of songbirds. Interestingly, Parrots are extremely altricial and show intense socio-vocal interactions from the nestling phase onward. In the current study we explore the development of communicative behavior during the nestling phase in the budgerigar (Melopsittacus undulatus), aiming to understand how begging calls of nestlings develop into contact calls of fledgelings, and what is the role of nestling' socio-acoustical experience in such process. Playback experiments using parental and unfamiliar contact calls, performed throughout...
The optic tectum in birds and its homologue the superior colliculus in mammals both send major bilateral, nontopographic projections to the nucleus rotundus and caudal pulvinar, respectively. These projections originate from widefield... more
The optic tectum in birds and its homologue the superior colliculus in mammals both send major bilateral, nontopographic projections to the nucleus rotundus and caudal pulvinar, respectively. These projections originate from widefield tectal ganglion cells (TGCs) located in layer 13 in the avian tectum and in the lower superficial layers in the mammalian colliculus. The TGCs characteristically have monostratified arrays of brush-like dendritic terminations and respond mostly to bidimensional motion or looming features. In birds, this TGC-mediated tectofugal output is controlled by feedback signals from the nucleus isthmi pars parvocellularis (Ipc). The Ipc neurons display topographically organized axons that densely ramify in restricted columnar terminal fields overlapping various neural elements that could mediate this tectofugal control, including the retinal terminals and the TGC dendrites themselves. Whether the Ipc axons make synaptic contact with these or other tectal neural elements remains undetermined. We double labeled Ipc axons and their presumptive postsynaptic targets in the tectum of chickens (Gallus gallus) with neural tracers and performed an ultrastructural analysis. We found that the Ipc terminal boutons form glomerulus-like structures in the superficial and intermediate tectal layers, establishing asymmetric synapses with several dendritic profiles. In these glomeruli, at least two of the postsynaptic dendrites originated from TGCs. We also found synaptic contacts between retinal terminals and TGC dendrites. These findings suggest that, in birds, Ipc axons control the ascending tectal outflow of retinal signals through direct synaptic contacts with the TGCs.
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The current classification of Chilean rhinocryptids includes eight species. Three of them contain subspecies that do not exhibit clear differences. Moreover, morphological, Ecological niches and behavioural differences among two lineages... more
The current classification of Chilean rhinocryptids includes eight species. Three of them contain subspecies that do not exhibit clear differences. Moreover, morphological, Ecological niches and behavioural differences among two lineages of the Scytalopus genera and two species of Pteroptochos are unclear. According to our results, there is no cutting criteria to establish differences among the three species of Scelorchilus albicollis, S.rubecula and Ptero- ptochos megapodius. We propose a new metho- dology based an level of ecological niches and behavioural patterns to understand the concept of speciation in this group of birds. Our results show how when integrating behaviour and ecological differences together with morphological chara- cters of the plumage, the distances among sister species in this group of birds are decreasing in relation with outgroup sister lineage of Furnariidae C.oustaleti, proposing an low and slow specia- tion in this group of birds. In general, we propose...
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The self-organization of neurotopies where neural connections follow Hebbian dynamics is framed in terms of linear operator theory. A general and exact equation describing the time evolution of the overall synaptic strength connecting two... more
The self-organization of neurotopies where neural connections follow Hebbian dynamics is framed in terms of linear operator theory. A general and exact equation describing the time evolution of the overall synaptic strength connecting two neural laminae is derived. This linear matricial equation, which is similar to the equations used to describe oscillating systems in physics, is modified by the introduction of non-linear terms, in order to capture self-organizing (or auto-organizing) processes. The behavior of a simple and small system, that contains a non-linearity that mimics a metabolic constraint, is analyzed by computer simulations. The emergence of a simple "order" (or degree of organization) in this low-dimensionality model system is discussed.
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We propose that to understand the biological and neurophysiological processes that give rise to human mental phenomena it is necessary to consider them as behavioral relational phenomena. In particular, we propose that: a) these phenomena... more
We propose that to understand the biological and neurophysiological processes that give rise to human mental phenomena it is necessary to consider them as behavioral relational phenomena. In particular, we propose that: a) these phenomena take place in the relational manner of living that human language constitutes, and b) that they arise as recursive operations in such behavioral domain. Accordingly, we maintain that these phenomena do not take place in the brain, nor are they the result of a unique operation of the human brain, but arise with the participation of the brain as it generates the behavioral relational dynamics that constitutes language.
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Cholinergic neurons in the parabigeminal nucleus of the rat midbrain were studied in an acute slice preparation. Spontaneous, regular action potentials were observed both with cell-attached patch recordings as well as with whole cell... more
Cholinergic neurons in the parabigeminal nucleus of the rat midbrain were studied in an acute slice preparation. Spontaneous, regular action potentials were observed both with cell-attached patch recordings as well as with whole cell current-clamp recordings. The spontaneous activity of parabigeminal nucleus (PBN) neurons was not due to synaptic input as it persisted in the presence of the pan-ionotropic excitatory neurotransmitter receptor blocker, kynurenic acid, and the cholinergic blockers dihydro-beta-erythroidine (DHβE) and atropine. This result suggests the existence of intrinsic currents that enable spontaneous activity. In voltage-clamp recordings, IH and IA currents were observed in most PBN neurons. IA had voltage-dependent features that would permit it to contribute to spontaneous firing. In contrast, IH was significantly activated at membrane potentials lower than the trough of the spike afterhyperpolarization, suggesting that IH does not contribute to spontaneous firin...
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ABSTRACT Georges Cuvier, founder of vertebrate paleontology and an anti-evolutionist who argued that in living beings the relation between the parts (organs) and the whole (the organism), as well as the relation between the whole and its... more
ABSTRACT Georges Cuvier, founder of vertebrate paleontology and an anti-evolutionist who argued that in living beings the relation between the parts (organs) and the whole (the organism), as well as the relation between the whole and its environment (way of existence or adaptation), are so exquisite and particular that a spontaneous or random origin of the living beings is totally unthinkable. Accordingly, he established a fundamental question, namely: 'how did living beings come to exist if not as a result of intentional design?' Here we argue that the current use of the notions of a genetic developmental program and of evolution as a process of genetic change are ultimately unsatisfactory as an answer to Cuvier's question. We propose a biological-historical approach to this question, based on the systemic-historical conceptualization of Natural Drift. Specifically, we propose that an organism comes to be a unique organized whole of mutually correspondent parts that exist as such through realizing a particular mode of relationship with its environment, neither as a consequence of design, nor by the operation of an internal building plan or program. This happens because the organism and its parts have arisen together in a historical systemic process that follows the course of the realization of the organism through its relation with its environment, both in ontogeny and phylogeny.
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Nocturnal animals that rely on their visual system for foraging, mating, and navigation usually exhibit specific traits associated with living in scotopic conditions. Most nocturnal birds have several visual specializations, such as... more
Nocturnal animals that rely on their visual system for foraging, mating, and navigation usually exhibit specific traits associated with living in scotopic conditions. Most nocturnal birds have several visual specializations, such as enlarged eyes and an increased orbital convergence. However, the actual role of binocular vision in nocturnal foraging is still debated. Nightjars (Aves: Caprimulgidae) are predators that actively pursue and capture flying insects in crepuscular and nocturnal environments, mainly using a conspicuous “sit-and-wait” tactic on which pursuit begins with an insect flying over the bird that sits on the ground. In this study, we describe the visual system of the band-winged nightjar (Systellura longirostris), with emphasis on anatomical features previously described as relevant for nocturnal birds. Orbit convergence, determined by 3D scanning of the skull, was 73.28°. The visual field, determined by ophthalmoscopic reflex, exhibits an area of maximum binocular ...