bluuebunny/crossref_metadata_2025_split huggingface dataset:
The paleostriatal system of Caiman crocodilus
Authors: Brauth Steven E. , Kitt Cheryl A. 
Published: January 2005

AbstractThe organization and projections of the presumed homologue of the mammalian corpus striatum, the ventrolateral area (VLA) of the telencephalon, were investigated in the reptile Caiman crocodilus. The caiman VLA was divided into two major cell fields on the basis of cytoarchitectonic criteria: a rostromedial small celled field (VLA s.c.) and a large celled field occupying the dorsal, lateral and ventrocaudal portions of the VLA (VLA l.c.). Histochemical results indicate that the VLA s.c. contains high levels of both cholinesterase and catecholamine (CA) activity. An intense lacy plexus of CA‐containing axons and terminals was found in the VLA s.c. Far less CA activity was found within the VLA l.c. CA activity within the VLA appears to be derived primarily from axons of cells located within a large field of the midbrain tegmentum which is called in this report nucleus tegmenti pedunculo pontinus (TP). In the caiman the VLA also receives projections from the CA‐positive cells of the locus ceruleus and from serotonin containing cells of the midline raphe system.Anatomical experiments indicate that the VLA L.C. receives projections from neurons in the VLA S.C. and projects upon these subtelencephalic cell groups: the anterior and posterior entopeduncular nuclei (ENa and ENp), the ventral lateral and ventral medial thalamic areas (Avl and Avm), the dorsal nucleus of the posterior commissure (nDCP), and TP. The VLA s.c. projects upon TP. ENa neurons project upon cells in the VLA l.c. Cells of Avl and Avm receive both paleostriatal and cerebellar projections; Avl neurons project upon portions of the rostral telencephalon external to the VLA. NDCP neurons project upon the optic tectum.The organization and projections of the VLA in Caiman crocodilus are compared to the organization and projections of the paleostriatal complex of the pigeon (Karten and Dubbeldam, '73; Brauth, Ferguson and Kitt, '78) and to the mammalian basal ganglia. The following paleostriatal characteristics appear to be common features in these species and may represent retained characteristics derived from the common ancestor: (1) an ascending catecholaminergic system derived from neurons in the midbrain tegmentum; (2) projections from the basal striatum upon the catecholamine containing neurons of the midbrain tegmentum; (3) an intrinsic cholinergic system; (4) projections upon thalamic cell groups which are also in receipt of cerebellar projections and which project upon telencephalic regions external to the paleostriatum; (5) reciprocal connections between the paleostriatum and the ventral or subthalamus; and (6) projections upon cell groups which project to the optic tectum. The results are discussed in terms of the overall role of the basal ganglia in the neural control of behavior.
Fine structure of noradrenaline nerve terminals in the dorsomedial portion of the nucleus tractus solitarii as demonstrated by a modified potassium permanganate method
Authors: Takahashi Yasuyuki , Tohyama Masaya , Satoh Keiji , Sakumoto Tetsuro , Kashiba Akira , Shimizu Nobuo 
Published: January 2005

AbstractFine structure of the noradrenaline (NA) nerve terminals in the dorsomedial portion of the nucleus tractus solitarii (NTS) was investigated by glyoxylic acid—potassium permanganate fixation method. The NA nerve terminals in this area contained a large number of small cored vesicles (SCV) (about 400‐600 Å in diameter) together with a few large cored vesicles (LCV) (about 1000 Å in diameter).The most frequent feature of NA nerve terminals observed in this area was axo‐dendritic contact. An axo‐axonic contact between NA and non‐NA terminals was also occasionally identified, while no axo‐somatic contact was found in this area as far as examined. At the contact zone between NA terminals and other neuronal elements, the following profiles suggestive of synapse‐like contact were identified: (1) somewhat dense material between contact membranes (intersynaptic filaments); (2) a slight accumulation of dense material adjacent to postcontact membranes; (3) disarrangement of contact membranes and enlargement of the space between these membranes; (4) aggregation of SCV and LCV to contact membranes.Finally it should be emphasized that NA nerve terminals often made a neuronal cluster or rosette with other neuronal elements, suggestive of a complicated role of NA on NTS function.
Receptive field properties of simple and complex striate neurons in Siamese cats
Authors: Chino Yuzo M. , Shansky Michael S. , Pizzi William J. 
Published: January 2005

AbstractResponses of striate cortical cells in Midwestern Siamese cats to moving slits and stationary flashed spots were recorded and compared to similar data in common cat controls obtained under identical experimental conditions. Over 90% of the neurons sampled had receptive fields within 10° of the area centralis.The proportion of binocularly excited cells in Siamese striate cortex was less than that found in the control cats, but more than has previously been reported, and was inversely related to the extent of convergent misalignment exhibited by each animal. Those striate neurons which could be driven by either eye had normal binocular receptive fields and demonstrated normal binocular interaction effects except facilitation.Receptive field dimensions (length, width, area) were significantly larger in Siamese than in common cats. For the simple cells, strabismic Siamese cats had larger receptive fields than orthophoric Siamese cats. Average spontaneous activity in Siamese cats was significantly higher than in the controls. However, similar encounter rates of simple, complex, and hypercomplex units were observed in both Siamese and common cats, and peak responses were not different. Velocity preference in complex Siamese units was shifted to slower velocities compared to common cat complex cells. A loss of direction selectivity was also revealed in the Siamese simple and complex neurons. Finally, sharpness of orientation tuning was dramatically reduced in Siamese complex cells, and this reduction was directly related to the extent of convergent squint exhibited by each animal. The results are discussed in terms of developmental anomalies and neurophysiological retinal abnormalities in Siamese cats.
The retinal projection to the superior colliculus in the cat: A quantitative study with HRP
Authors: Wässle H. , Illing R.‐B. 
Published: January 2005

AbstractThe projections of cat retinal ganglion cells to the superior colliculus (SC) were examined using the method of retrograde axonal transport of horseradish peroxidase (HRP). Several injections of HRP were made in a single SC after the visual projection to the injection sites had been established physiologically. The HRP injections resulted in a homogeneous distribution of labelled ganglion cells in whole mount preparations of the retinae of both eyes. In the eye contralateral to the injected colliculus, ganglion cells with a crossed projection were labelled in both nasal and temporal retina; in the ipsilateral eye, ganglion cells with uncrossed projection were labelled only in the temporal retina. Analysis of the counterstained retinal whole mounts indicated that at least 50% of all ganglion cells in the nasal retina and 26% in the temporal retina have a crossed projection to SC, and that 24% of all ganglion cells of the temporal retina have an uncrossed projection to the SC.The morphological classes of retinal ganglion cells have different patterns of crossed/uncrossed decussation and they participate in varying proportions in the retino‐tectal projection. Almost all Alpha cells in the retina send axon collaterals to the SC. Probably only about 10% of the Beta cells project to the SC and at least 80% of all Gamma cells send axons to the SC.
Differntial discrimination of appropriate pathways by regenerating identified neurons in Helisoma
Authors: Murphy A. D. , Kater S. B. 
Published: January 2005

AbstractPathway selection by two different identified neurons (neuron 4 and neuron 5) in the pond snail Helisoma was studied by intracellular injection of the fluorescent dye, Lucifer Yellow CH. The axonal projections of these neurons in normal animals are remarkably constant. Axons of neuron 4 and 5 share a common nerve, the esophageal trunk (ET), which bifurcates to form the gastric nerve (GN) and the salivary nerve (SN). Neuron 5's axon traverses the GN and “avoids” the SN; neuron 4's axon traverses the SN and “avoids” the GN. On rare occasions when neuron 4 enters the GN it may make right angle turns, leave the gastric nerve cylinder, and extend directly to its target, the salivary glands. Anomalously located neuron 4 somata also may extend axons to their correct targets via unusual routes. Following ET crush both neurons 4 and 5 regenerate. Sprouts from neuron 5 encountering the bifurcation of the ET basically recapitulate the normal neuron 5 axonal projection. In contrast, neuron 4 sprouts indiscriminately into “correct” and “incorrect” branches of the ET. These experiments indicate that pathway selection by growing neurites can be differentially and specfically regulated for different neurons of the same nerve trunk. The fidelity of different regenerating neurons for selecting nerves which normally contain their axons differs. Though the mechanism of pathway selection cannot yet be identified, the regenerate axonal projections cannot be accounted for by direct guidance of sprouts by the surviving distal axon segments, as has been reported for some identified neurons in the leech.
Subnuclear organization of the ophidian trigeminal motor nucleus.I. Localization of neurons and synaptic bouton distribution
Authors: Moody Sally A. , Meszler Richard M. 
Published: January 2005

AbstractAmong the Reptilia the morphology of the trigeminal (V) motor nucleus is a rather good indicator of the sophistication of jaw kinetics. As it becomes more complex, the nucleus shifts ventrolaterally and becomes divisible into subnuclear groups. The cottonmouth moccasin, a pit viper with very finely developed jaw musculature and kinetics, has a very large V motor nucleus. It is divisible into three subnuclei: the ventral and intermediate, containing predominantly large neurons (40–60 μm), and the dorsal subnucleus, containing only small neurons (20 μm).Ultrastructural study has indicated that these subnuclei can also be characterized according to the types of boutons synapsing on the cells. The soma of neurons in the ventral and intermediate subnuclei have up to 50% of their profile covered with clusters of boutons. The neurons of the dorsal subnucleus usually have only one cluster of two to three boutons per profile. Both cell types have more boutons containing spherical vesicles in axo‐dendritic synapses than those containing flattened vesicles, and approximately equal numbers of these boutons in axosomatic contacts. However, the small cells have proportionately more boutons containing spherical vesicles synapsing on them.Boutons similar to those described in mammalian spinal cord were identified in the snake V motor nucleus. Small terminals containing spherical (S) or flattened (F) vesicles and terminals associated with postsynaptic cisternae (C) or with dense bodies (T) are commonly found in the ventral and intermediate subnuclei. C‐ and T‐boutons are rare in the dorsal subnucleus. Large terminals with multiple active sites and postsynaptic dense bodies (M) and their associated, small, preterminal boutons (P) were not observed in the snake V motor nucleus. Boutons containing only large granular vesicles (G) were also not observed.We suggest that the ventral and intermediate subnuclei consist of α‐ and possibly β‐motoneurons and the dorsal subnucleus contains γ‐motoneurons. This anatomical segregation of function may be important to the physiology of ophidian mastication, which is quite different from that of mammals. However, there do exist several morphological similarities to mammals, suggesting that the snake brainstem may be a good model for comparative structure–function correlations.
Somatosensory thalamus of a prosimian primate (Galago senegalensis). I. Configuration of nuclei and termination of spinothalamic fibers
Authors: Pearson J. C. , Haines D. E. 
Published: January 2005

AbstractThe configuration of somatosensory relay nuclei and termination of spinothalamic fibers were studied in the dorsal thalamus of a prosimian primate (Galago senegalensis) using Nissl, Klüver and Barrera ('53), Weil ('45), and Fink and Heimer ('67) methods. The ventral posterolateral nucleus (VPL) is divided into medial and lateral parts (VPLm and VPLl, respectively) by a sheet‐like lamina of fibers. Spinothalamic input to Galago VPL is somatopically arranged; input from the forelimb terminates in VPLm and that from hindlimb in VPLl. In addition, preterminal debris in caudal VPL is dense and organized into “parcellated bursts” (terminology of Mehler, '69). Consequently, the nature of the spinothalamic debris in VPL of Galago is similar to that reported for higher primates (Mehler et al., '60). Located dorsomedial to the rostral extension of VPL is a zone of large, deeply staining cells designated as the ventral intermediate nucleus (Vim). Following hemisection at either cervical or lumbar spinal cord levels, preterminal debris, independent of that coursing into VPL, enters the Vim. This substantiates the presence of an intermediate nucleus (i.e., Vim) between VPL and the more rostral ventral lateral nucleus.In the medial thalamic region, axonal degeneration is located in the central lateral nucleus (CL) and in the densocellular and the multiform portions of the dorsomedial nucleus. Only fibers of passage are identified in the centre median, the paracentral and the subparacentral nuclei. The posterior nuclear group (PO) in Galago is divided into medial and lateral parts designated as POm and POl, respectively. In addition, PO contains three distinct nuclei: 1) the magnocellular (MC) portion of the medial geniculate nucleus; 2) the nucleus limitans (Lim); and 3) the suprageniculate nucleus (SG). Following spinal cord hemisection, preterminal debris is located throughout the POm and around cells of the MC. Lim and SG contain no discernible degeneration. Preterminals are also found in a group of cells designated as the caudal part of the central lateral nucleus (CLC).
An experimental study of the ventral striatum of the golden hamster. I. Neuronal connections of the nucleus accumbens
Authors: Newman Richard , Winans Sarah Schilling 
Published: January 2005

AbstractAs part of an experimental study of the ventral striatum, the horseradish peroxidase (HRP) method was used to examine the afferent and efferent neuronal connections of the nucleus accumbens. Following iontophoretic applications or hydraulic injections of HRP in nucleus accumbens, cells labeled by retrograde transport of HRP were observed in the ipsilateral telencephalon in the posterior agranular insular, perirhinal, entorhinal, and primary olfactory cortices, in the subiculum and hippocampal field CA1, and in the anterior and posterior divisions of the basolateral amygdaloid nucleus. In the diencephalon, labeled neurons were present ipsilaterally in the central medial, paracentral and parafascicular intralaminar nuclei, and in the midline nuclei parataenialis, paraventricularis, and reuniens. Retrograde labeling was observed in the ipsilateral brainstem in cells of the ventral tegmental area and dorsal raphe. Many of these projections to nucleus accumbens were found to be topographically organized.Anterograde transport of HRP from nucleus accumbens demonstrated ipsilateral terminal fields in the ventral pallidum and substantia nigra, pars reticulata.The afferent projections to nucleus accumbens from the posterior insular and perirhinal neocortices, intralaminar thalamus, and the dopamine‐containing ventral tegmental area are analogous to the connections of the caudatoputamen, as are the efferents from nucleus accumbens to the substantia nigra and ventral globus pallidus. These connections substantiate the classification of nucleus accumbens as a striatal structure and provide support for the recently proposed concept of the ventral striatum. Furthermore, the demonstration that a number of limbic system structures, including the amygdala, hippocampal formation, entorhinal cortex, and olfactory cortex are important sources of afferents to the nucleus accumbens, suggests that the ventral striatum may serve to integrate limbic information into the striatal system.
Postnatal development of dopaminergic cells in the rat retina
Authors: Kato S. , Nakamura T. , Negishi K. 
Published: January 2005

AbstractBy means of a histofluorescence technique (FGS method), a postnatal ontogeny of dopaminergic neurons (DA‐cells) in the retina was studied in rats which had been born and reared under diurnal lighting (LD), reversed lighting (DL), constant lighting (LL), or continuous dark conditions (DD). The time of first appearance of DA‐cells was not altered by any of the above conditions; weakly fluorescent cell bodies were visible at about the 10th postnatal day. After the eyes were open the DA fluorescence of the cell body was gradually increased in intensity in all LD, DL, and LL rats, but not for DD rats. At the 16–17th day the processes of the cell first became visible, extending laterally to the inner plexiform layer. The somata and their processes appeared to be well developed at the postnatal 4–6th week, and they resembled those of the adult rat. On the other hand, the DA‐cells in the DD rats showed a weak fluorescence in both the somata and their processes. When the DD rats were transferred and reared under LD conditions for 1–3 days, the DA fluorescence was increased. These results strongly suggest that the initiation of retinal DA synthesis is independent of environmental lighting condition, but an adequate light stimulus is required for continued normal development of DA‐cells. Unlike in the rat, fluorescent cells in the guinea pig and chick retinas were observed to be fairly mature at birth or hatching. The developmental pattern of DA‐cells in the three species examined coincides with the maturation of visual function.
Development of the dorsal lateral geniculate nucleus in normal and visually deprived siamese cats
Authors: Robertson T. W. , Hickey T. L. , Guillery R. W. 
Published: January 2005

AbstractNeuronal cell bodies in the lateral geniculate nucleus of normal and of monocularly‐deprived Siamese cats have been measured. Seventeen normally reared Siamese cats, ranging in age between 20 and 120 days, were used to determine rates of normal geniculate cell growth. A second group of five adult Siamese cats reared from birth with the lids of one eye closed were used to study the effects of monocular visual deprivation upon geniculate cell size. For each of the normal and visually deprived Siamese cats, the cross‐sectional areas of 600 lateral geniculate cells were measured from camera lucida drawings of Nissl preparations.During normal development the geniculate cells rapidly increase in size during the first postnatal month of life and reach their adult size sometime between days 28 and 56. While this course of geniculate cell growth is similar to that seen in normally pigmented cats, the pattern of change seen after monocular deprivation is quite different in Siamese cats from that found in normally pigmented cats. In Siamese cats the regions of the nucleus receiving a contralateral projection from the deprived eye appear to be shielded from the effects of binocular competition. Cells throughout lamina A and in the abnormal, contralaterally innervated segment of lamina A1 show only about a 10% reduction in cell size. There are no noticeable differences between the parts of lamina A in the binocular and monocular segments of the nucleus. Cells in the ipsilaterally innervated segment of lamina A1, in contrast, show deprivation‐induced changes that average 27.1%.Two mechanisms are proposed to explain why some geniculate cells in Siamese cats appear to be shielded from binocular competition: one depends on possible interactions between geniculo‐cortical cells lying in adjacent parts of the same geniculate lamina, and the other depends on an anatomical segregation of the cell type (“Y‐cells”) most heavily affected by the binocular competition. Each proposed mechanism is related to earlier observations on monocularly deprived, normally pigmented cats.
Pattern of development of ascending and descending fibers in embryonic spinal cord of chick: I. Role of position information
Authors: Nornes Howard O. , Hart Henry , Carry Michael 
Published: January 2005

AbstractPrevious studies on the rigid time and position pattern of embryonic spinal cord development are extended to include the pattern of growth of axonal processes. This study was designed to analyze the position of axons in the marginal zone as they course (fasciculate) in the ascending and descending direction from a single spinal segment. Injections of 3H‐proline were made into L1 or T6 of chick embryos of stages 21–29 (3.5–6 days of incubation). The location of radioactive label in the marginal zone was analyzed autoradiographically to show the location of labeled axons originating from the injected segment. In the early stages of development (stage 21), the labeled descending axons were located in the most ventromedial aspect of the marginal zone. The labled ascending axons were located more laterally and to the perimeter of this zone. In stages 27–29, the labeled axons near the site of injection were located in the inner two‐thirds of the marginal zone, and in the progressively more rostral levels the label shifted laterally and to the perimeter in a laminar pattern. It was concluded that the labeled ascending axons from an individual spinal segment layer upon the axons which originate from the more rostral segments. How this rigid time and position pattern of axonal growth can impart a topographic order into fiber tracts of the spinal cord was discussed.
Gradients between nasal and temporal areas of the cat retina in the properties of retinal ganglion cells
Authors: Stone Jonathan , Leventhal Audie , Watson Charles R. R. , Keens Jeremy , Clarke Rosemary 
Published: January 2005

AbstractEvidence is presented of gradients between nasal and temporal areas of the cat's retina in the properties of their ganglion cell populations. Mean ganglion cell size is greater in temporal retina than in nasal retina, partly because the α‐ and β‐cells of temporal retina are distinctly bigger than their counterparts in nasal retina, and partly because more medium‐sized cells, and fewer small cells, are to be found in temporal retina. This high proportion of medium‐sized ganglion cells may reflect a high proportion of β‐cells or of the medium sized γ‐cells described by Stone and Clarke ('80). Several of these differences can be related to prior morphological, electrophysiological, and behavioural observations in the cat, and similar differnces have been reported in several other mammalian species. Evidence is presented that, in the cat, at least some of these differences are less marked near the vertical meridian of the retina than more temporally or nasally. The present results may therefore, be evidence of a nasal‐temporal gradient in retinal structure and function common to many mammals, and distinct from previously recognised gradients in ganglion cell properties related to the area centralis and visual streak specialisations.