bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunocytochemical localization of amyloid precursor protein in rat brain
Authors: Ouimet Charles C. , Baerwald Kristine D. , Gandy Samuel E. , Greengard Paul 
Published: January 2005

AbstractThe localization ofamyloid precursor protein (APP) in rat brain was studied with a cytoplasmic domain‐specific antibody. Light microscopic immunocytochemistry demonstrated that APP is present in most neurons, in some oligodendrocytes, and in a population of cells with diameters less than 10 μm that may be glial. Marked differences in immunoreactivity among neurons were observed, and the strongest immunoreactivity was contained in larger neurons. Neurons with scant cytoplasm, such as granule cells in the olfactory bulb, dentate gyrus, and cerebellum, were weakly immunoreactive. Differences in neuropil immunoreactivity were also observed; this type of staining was strongest in the caudatoputamen, lateral septum, medial habenula, nucleus reticularis of the dorsal thalamus, and the lateral portion of the ventroposterior nucleus. Neuropil immunostaining was weakest in layer IV of cortex and in areas containing granule cells. The fact that APP seems to be present in the vast majority of neurons suggests that this protein plays a role common to all neurons. The fact that there is a great difference in the steady‐state amount of APP among different types of neurons suggests that APP may play a specific role in the function of certain classes of neurons. © 1994 Wiley‐Liss, Inc.
Physiology and morphology of complex spiking neurons in the guinea pig dorsal cochlear nucleus
Authors: Manis Paul B. , Spirou George A. , Wright Debora D. , Paydar Sussan , Ryvgo David K. 
Published: January 2005

AbstractIntracellular recordings from the dorsal cochlear nucleus have identified cells with both simple and complex action potential waveforms. We investigated the hypothesis that cartwheel cells are a specific cell type that generates complex action potentials, based on their analogous anatomical, developmental, and biochemical similarities to cerebellar Purkinje cells, which are known to discharge complex action potentials. Intracellular recordings were made from a brain slice preparation of the guinea pig dorsal cochlear nucleus. A subpopulation of cells discharged a series of two or three action potentials riding on a slow depolarization as an all‐or‐none event; this discharge pattern is called a complex spike or burst. These cells also exhibited anodal break bursts, anomalous rectification, subthreshold inward rectification, and frequent inhibitory postsynaptic potentials (IPSPs). Seven complex‐spiking cells were stained with intracellular dyes and subsequently identified as cartwheel neurons. In contrast, six identified simplespiking cells recorded in concurrent experiments were pyramidal cells.The cartwheel cell bodies reside in the lower part of layer 1 and the upper part of layer 2 of the nucleus. The cells are characterized by spiny dendrites penetrating the molecular layer, a lack of basal dendritic processes, and an axonal plexus invading layers 2 and 3, and the inner regions of layer 1. The cartwheel cell axons made putative synaptic contacts at the light microscopic level with pyramidal cells and small cells, including stellate cells, granule cells, and other cartwheel cells in layers 1 and 2. The axonal plexus of individual cartwheel cells suggests that they can inhibit cells receiving inpt;t from either the same or adjacent parallel fibers and that this inhibition is distributed along the isofrequency contours of the nucleus. © 1994 Wiley‐Liss, Inc.
Distribution of Purkinje cell‐specific Zebrin‐II/aldolase C immunoreactivity in the mouse, rat, rabbit, and human retina
Authors: Caffé A. R. , von Schantz M. , Szél A. , Voogd J. , van Veen T. 
Published: January 2005

AbstractThe developmental, genetic, and biochemical similarities that have been observed between the cerebellum and retina form the basis for ongoing investigations into retinal expression of cerebellar‐specific proteins. We have examined the mouse, rat, rabbit, and human retina for expression of a protein that is present in parasagittal Purkinje cell strips and that is recognized by the antibody Zebrin‐II. This protein has recently been identified as a member of the aldolase C isoenzymes. Western blotting and immunocytochemistry have been used.The monoclonal antibody Zebrin‐II recognized a prominent 36 kDa protein band on immunoblots of both the cerebellum and the retina of the examined species. Immunocytochemistry showed that, in the three nonhuman species, cells were stained in the ganglion cell layer (GCL). In addition, in the mouse and rabbit, cells in the inner nuclear layer (INL) were also labeled. Except for the visual streak, there were more immunopositive cells in the rabbit GCL and INL than in corresponding areas of the mouse retina. In the human, in contrast to the other species, the photoreceptor cell layer was strongly aldolase C immunoreactive. In the h all species except for the rat, the photoreceptor inner segments also displayed a weak labeling.The results show that this aldolase C isoenzyme is another protein that is selectively expressed by the cerebellum: and retina. Furthermore, the retinal expression is species specific, and this pattern seems to show a good correlation with the oxygenation level of the individual compartments. The indication that this aldolase C isoenzyme has specific developmental functions in the retina provides additional clues for our understanding of cerebellar organization. © 1994 Wiley‐Liss, Inc.
Undernutrition during early life does not affect the number of granule cells in the rat olfactory bulb
Authors: Tolley Lynn K. , Bedi Kuldip S. 
Published: January 2005

AbstractUndernutrition during early life causes deficits and distortions of brain structure. However, whether or not this includes a diminution of the total numbers of neurones remains uncertain. Recent advances in stereological techniques have made it possible to obtain unbiased cells in well‐defined biological structures. Rats were undernourestimates of total number of cells in well‐defined biological structures. Rats were undernourished from conception to 90 postnatal days of age by standardised procedures. Groups of well‐fed control and undernourished rats were anaesthetised and killed by intracardiac perfusion with fixatives at 30 and 90 days of age. Each olfactory bulb was serially sectioned at a nominal thickness of 100 pm on a vibratome. These sections were analysed by the Cavalieri principle to obtain estimates of the total volume of the olfactory bulb as well as the volume of its granule cell layer. The physical “disector” method was later used on serial 1‐μm‐thick toluidine‐blue‐stained sections to estimate the numerical density of granule cell neurones in the olfactory granule cell layer. These values were used to compute estimates of the total number of olfactory granule cell neurones for each animal. Thirty‐day‐old control and undernourished rats had between 2.6 and 3 million granule cell neurones in the olfactory bulb. By 90 days of age the number of granule cells had increased in both groups of animals to between about 4.2 and 5.2 million cells. Analysis of variance tests showed a significant main effect of age but not nutrition in these estimates. Although the interaction term did reach statistical significance, post hoc analysis did not reveal any differential effect of undernutrition between the two age groups examined. Therefore, undernutrition of rats from conception until 90 postnatal days of age does not seem to affect the total numbers of granule cell neurones in the olfactory bulbs. © 1994 Wiley‐Liss, Inc.
Anatomical connections of the primate pretectal nucleus of the optic tract
Authors: Mustari Michael J. , Fuchs Albert F. , Kaneko Chris R. S. , Robinson Farrel R. 
Published: January 2005

AbstractThe pretectal nucleus of the optic tract (NOT) plays an essential role in optokinetic nystagmus, the reflexive movements of the eyes to motion of the entire visual scene. To determine how the NOT can influence structures that move the eyes, we injected it with lectin‐conjugated horseradish peroxidase and characterized its afferent and efferent connections. The NOT sent its heaviest projection to the caudal half of the ipsilateral dorsal cap of Kooy in the inferior olive. The rostral dorsal cap was free of labeling. The NOT sent lighter, but consistent, projections to other visual and oculomotor‐related areas including, from rostral to caudal, the ipsilateral pregeniculate nucleus, the contralateeral NOT, the lateral and medial terminal nuclei of the accessory optic system bilaterally, the ipsilateral dorsolateral pontine nucleus, the ipsilateral nucleus prepositus hypoglossi, and the ipsilateral medial vestibular nucleus. The NOT received input from the contralateral NOT, the lateral terminal nuclei bilaterally, and the ipsilateral pregeniculate nucleus. Although our injections involved the pretectal olivary nucleus (PON), there was neither orthograde nor retrograde labeling in the contralateral PON. Our results indicate that the NOT can influence brainstem preoculomotor pathways both directly through the medial vestibular nucleus and nucleus prepositus hypoglossi and indirectly through both climbing and mossy fiber pathways to the cerebellar flocculus. In addition, the NOT communicates strongly with other retino‐recipient zones, whose neurons are driven by either horizontal (contralateral NOT) or vertical (medial and lateral terminal nuclei) fullfield image motion. © 1994 Wiley‐Liss, Inc.
Projections from the lateral and interposed cerebellar nuclei to the thalamus of the rat: A light and electron microscopic study using single and double anterograde labelling
Authors: Aumann T. D. , Rawson J. A. , Finkelstein D. I. , Horne M. K. 
Published: January 2005

AbstractThe lateral and interposed cerebellar nuclei may have different functions in the control of movement. Efferent fibres from both nuclei project predominantly to areas of the thalamus, which in turn project to the motor cortex. In this study, single and double anterograde‐tracing techniques have been used to examine and compare the pathways from the lateral and interposed nuclei to the thalamus in the rat by using both light and electron microscopy to look for evidence of organisational or structural features that may underlie the proposed functional differences between these nuclei.Terminals from the lateral nucleus were found to be located most medially in the thalamus, predominantly in the ventral lateral nucleus and the rostral pole of the posterior nuclear group. Terminals from the posterior interposed nucleus were located slightly rostral and lateral to those from the lateral nucleus, mainly around the border between the ventral lateral nucleus and the ventral posterior medial nucleus. Terminals from the anterior interposed nucleus were located slightly rostral and lateral to those from the posterior interposed nucleus, predominantly in the rostral pole of the ventral posterior lateral nucleus. Terminals from the lateral and interposed nuclei were also found in double anterograde‐tracing experiments to be nonoverlapping in the regions between these main areas of termination. The structure of terminals from the lateral and interposed nuclei, however, as well as their synaptic relationship with thalamic neurones, were found to be similar. The terminals are large and form synapses with proximal dendrites of thalamic neurones. They contained round vesicles and formed multiple synaptic contacts with dendritic shafts, as well as dendritic spines.The findings indicate that information from the lateral and interposed nuclei is processed in separate regions of the thalamus but that the mode of synaptic transfer to thalamic neurones is likely to be similar for the two projections. © 1994 Wiley‐Liss, Inc.
Distribution of calcium‐binding protein calbindin‐D28k in the auditory system of adult and developing rats
Authors: Friauf Eckhard 
Published: January 2005

AbstractCalbindin‐D28k (CaBP) is a calcium‐binding protein, which appears to be involved in the buffering of free intracellular calcium and may thereby contribute to calcium homeostasis. This study attempted to determine the distribution pattern of CaBP immunoreactivity in the central auditory system of adult rats and during development, when calcium ions play key roles in several aspects of nerve cell function. It was found that most steps during CaBP development occur postnatally in the central auditory system. With the exception of the lateral superior olive, the ventral and the intermediate nuclei of the lateral lemniscus, and the auditory cortex, which already express CaBP prenatally, CaBP immunoreactivity is not present before postnatal day 2 (P2). Development proceeds until about P24, when the pattern characteristic of adult animals can be seen. There was no detectable sequence in CaBP development from lower to higher stations in the auditory pathway, i.e., the different nuclei appear to express CaBP independently of each other, indicating that intrinsic, rather than peripheral, maturation processes may predominantly influence CaBP expression.Neurons in four brainstem nuclei (the lateral superior olive, the ventral and intermediate nuclei of the lateral lemniscus, and the central nucleus of the inferior colliculus) express CaBP only transiently. In these nuclei, CaBP immunoreactivity peaks between P6 and P18, which coincides with the period of synapse stabilization. Therefore, CaBP may play a specific role during neuronal development, by buffering the concentration of intracellular free Ca2+, which may be necessary for modification of synaptic efficiency. © 1994 Wiley‐Liss, Inc.
Paraventriculospinal tract as a model for axon injury: Spinal cord
Authors: van den Pol Anthony N. , Collins William F. 
Published: January 2005

AbstractThe response of immunocytochemically identified hypothalamic axons innervating the rat spinal cord was examined at varying times after cord hemisection in a model of axonal injury using the paraventriculospinal projection. The purpose was to determine whether these long descending peptidergic axons would show signs of regrowth after injury. From 1 to 180 days after hemisection, horizontal sections of the spinal cord were stained with peroxidase immunocytochemistry. Antiserum against neurophysin was used to identify axons projecting from the hypothalamic paraventricular nucleus to the spinal cord. The paraventricular nucleus innervates all rostrocaudal segments of the cord, yet the projection is not massive, allowing the trauma response of individual axons to be studies.Immediately caudal to a T4 hemisection, axons began decreasing in number by 2 days after surgery. Ten days postoperatively, only a few axons could be found caudal to the cut; these remaining axons arose from the contralateral cord. A substantial increase in the number of stained axons was found rostral to the hemisection 3–12 weeks after surgery. In that an increase in axon number could be due to both increasing staining efficacy and sprouting, the orientation of axons in control and hemisected rats was studied. Three millimeters rostral to the hemisection, axons had a greater variance in orientation and were more likely to project medially out of the dorsolateral white matter compared with the contralateral control side. Rostral to the hemisection, a statistically significant two‐ to fourfold increase in the number of branches per axon was found in comparison to the contralateral control side. Axons were found in the dorsal white matter 4 months after surgery; in controls, immunostained axons were not found here. At all intervals after surgery, structures suggestive of growth were found, including terminal growth cones and lateral filopodia and lamellipodia extending from axons whose distal ends had been severed by hemisection. Similar structures were not found in control spinal cord. Together, these data suggest that after cord hemisection, axons from the paraventricular nucleus sprout rostral to the injury. © 1994 Wiley‐Liss, Inc.
Architectonic subdivisions of the motor thalamus of owl monkeys: Nissl, acetylcholinesterase, and cytochrome oxidase patterns
Authors: Stepniewska Iwona , Preuss Todd M. , Kaas Jon H. 
Published: January 2005

AbstractAs the first part of an investigation of the motor thalamus and its cortical connections in the owl monkey, a New World anthropoid primate, we studied thalamic architecture by using stains for Nissl, acetylcholinesterase (AChE), and cytochrome oxidase (CO), in order to identify subdivisions of the ventrolateral thalamic region as well as other nuclei with motor connections. Material was obtained from brains cut in the frontal, horizontal, and parasagittal planes. Our results indicate that the ventrolateral thalamic region (VL) of owl monkeys is a heterogeneous structure composed of several architectonic subdivisions that resemble divisions that have been described in macaques and other Old World anthropoids. All of these subdivisions are more readily distinguished in AChE than in Nissl or CO preparations.The anterior part of VL, VLa (VLo of Olszewski), is characterized by clusters of medium‐sized, darkly stained neurons. VLa is also distinguished by AChE‐positive cells embedded in a matrix of neurites as well as by a characteristic dark, irregular net of blood vessels. The posterior part of VL is rather uniform cytoarchitectonically and contains large, darkly stained, and sparsely distributed neurons. However, we were able to distinguish three subdivisions of posterior VL that closely correspond to structures described by Olszewski in macaques: a principal segment, VLp (VPLo of Olszewski), a medial segment, VLx (“area X” of Olszewski), and a dorsal segment, VLd (VLc and VLps of Olszewski). In AChE, VLd is much darker than the other divisions. The distinction between VLp and VLx, which together make up the largest part of VL, is less marked, although VLp is somewhat darker and more irregular in appearance in AChE than is VLx. © 1994 Wiley‐Liss, Inc.
Early development of the optic chiasm in the gray short‐tailed opossum, Monodelphis domestica
Authors: Taylor J. S. H. , Guillery R. W. 
Published: January 2005

AbstractWe have studied the early development of the uncrssed retinofugal projection in the gray short‐tailed opossum. Axons that form the adult uncrossed retinofugal projection arise from the temporal crescent of the retina and reach the optic chiasm on postnatal day 7. The sites at which the uncrossed fibres segregate from the crossed fibres and the pattern of this segregation are very different from those seen in eutherian mammals. In the opossum, the uncrossed fibres segregate from the crossed fibres within the juxtachiasmatic part of the optic nerve before they have encountered either the fibres of the other eye or midline structures of the ventral diencephalon. The uncrossed fibres turn perpendicular to the axis of the nerve and grow dorsoventrally through the crossed projection to gather as a discrete bundle at the ventral edge of the nerve. The abrupt divergence of the uncrossed fibres occurs at a border between two glial cell types: the interfascicular glia that characterise the main part of the optic nerve and the radial glia of the juxtachiasmatic part of the nerve. At the ventral part of the nerve, the bundle of uncrossed fibres turns caudally across the axis of the nerve and enters the ipsilateral optic tract. When retinofugal fibres encounter the border between the interfascicular and radial glia, a very specific axonal reorganisation occurs in marsupials, and this is strikingly different from the axonal reorganisation that occurs at the same site in eutherians, where essentially all retinofugal fibres reorganise, not just the uncrossed component. We believe this to be an important example of an identified cellular element that has quite distinct axon‐guidance properties in different species. © 1994 Wiley‐Liss, Inc.
GABAA receptor α1 subunit, an early marker for area specification in developing rat cerebral cortex
Authors: Paysan Jacques , Mohler Hanns , Fritschy Jean‐Marc , Paysan Jacques , Bolz Jürgen 
Published: January 2005

AbstractChanges in the expression of neurotransmitter receptors in developing cerebral cortex may be related to the functional maturation of distinct areas. In the present study, we have tested whether GABAA receptor expression in neonatal rats reflects the differentiation of cortical areas. Specifically, the α1 subunit, one of the most prevalent GABAA receptor subunits in adult cerebral cortex, is up‐regulated postnatally, suggesting a link with the establishment of inhibitory circuits. Using immunohistochemistry with a subunit‐specific antiserum, we observed a striking area‐ and lamina‐specific increase in staining for GABAA receptors containing the α1 subunit (α‐GABAA receptors), from low levels in neonates to an intense and uniform staining in adults. Already at birth, the α‐subunit immunoreactivity selectively demarcated the boundaries of certain cortical areas. In particular, the primary somatosensory (S1) and visual (V1) areas were distinctly delineated with a band of α1‐subunit immunoreactivity located in the developing layers III and IV. The staining ended abruptly at the presumptive boundaries of S1 and V1, adjacent areas being unstained at this age. Around postnatal day 3, clusters of α‐subunit positive cells were seen in layers III–IV of S1 and V1 extending their dendrites up to layer I, where they arborized profusely. In addition, the distribution of α‐GABAA receptors in S1 revealed in detail the differentiation of the barrel field during early postnatal development. Although staining was observed in all areas by postnatal day 6, differences in the laminar distribution of α‐GABAA receptors persisted for at least 1 more week. Our results provide evidence for the existence of area‐specific boundaries in neocortex of newborn rats before layers III–IV are fully differentiated and innervated by cortical afferents. Furthermore, the area‐ and lamina‐specific maturation of α‐GABAA receptor staining demonstrates the value of this marker for investigating the cytoarchitectonic differentiation of cortical areas during development. 1994 Wiley‐Liss. Inc.