bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cerebellar nuclei and the nucleocortical projections in the rat: Retrograde tracing coupled to GABA and glutamate immunohistochemistry
Authors: Batini Cesira , Compoint Claude , Buisseret‐Delmas Catherine , Daniel Herve , Guegan Maryvonne 
Published: January 2005

AbstractThe amino acids GABA and glutamate (Glu) are thought to be the principal substances in the central nervous system responsible for neuronal inhibition and excitation. Their distributions among the different neurons in a defined pathway may thus be indicative of the contributions of the cells to pathway function. Examples of such neurons are those of the cerebellar nuclei which, while regulating output from the Purkinje cells of the cerebellar cortex, are also found to project back to the cerebellar cortex.Immunohistochemical experiments were done to identify GABA and glutamate (Glu) containing cells in the adult rat cerebellar nuclei. Consecutive semithin and serial vibratome sections were incubated with antisera raised in rabbit against GABA and Glu. In semithin sections, only small neurons were intensely GABA immunoreactive (GABA‐IR) (31.7%), and the majority (80.5%) were Glu immunoreactive (Glu‐IR) of different sizes. Consistent with Glu being a metabolic precursor for GABA, 75.4% of the GABA‐IR population colocalized Glu. In vibratome sections GABA‐IR neurons showed some local differences in number, whereas the Glu‐IR were uniformly distributed in the three nuclei studied. Measured mean diameters for these neurons showed a distinct size difference for the GABA‐ and Glu‐IR with little overlap.Cerebellar nuclei neurons projecting to the cortex (nucleocortical neurons, NCN) were identified by locally preinjecting the retrograde transported WGA‐apo HRP‐colloidal gold complex in the cerebellar cortex. Vibratome sections of these cerebella were silver intensified for the retrograde tracer and double labeled for GABA and Glu. Of the total number of identified NCN, 8.7% were GABA‐IR (10 animals) and 47.7% Glu‐IR (5 animals). Many retrograde labeled NCN in the core of the thick sections were immunonegative for both amino acids due to poor antibody penetration, thus underestimating the proportions of cells containing GABA and Glu. The size distributions for the GABA‐IR and Glu‐IR NCN were similar to those measured in non‐retrograde labeled nuclei in thick sections.The conclusions reached are that GABA‐IR neurons of the cerebellar nuclei, including the NCN, use GABA as the presumed inhibitory neurotransmitter and that Glu‐IR neurons may use Glu or another excitatory neurotransmitter.
Dendritic sampling across processing streams in monkey striate cortex
Authors: Malach Rafael 
Published: January 2005

AbstractCytochrome oxidase (CO) dense blobs in primate striate cortex provide a striking example of parallel processing of visual information. The level of isolation of the blobs from the surrounding interblob tissue was investigated in the present study by combining CO staining with Golgi impregnation of dendritic arbors in the same tissue sections. The data are based on material from two marmoset and three squirrel monkeys. The analysis was conducted on two types of Golgi preparations. In the first preparation, dense networks of overlapping dendrites were impregnated over blob margins. The results of analyzing these networks with transmission and confocal microscopy revealed that dendritic arbors penetrate freely through blob margins. Statistical analysis revealed that the density of dendritic crossings at blob margins was similar to that found at blob and interblob centers. In the second type of Golgi preparation, single, isolated neurons were impregnated. Studies of such neurons revealed occasional examples of dendritic arbors that appeared to reflect back from blob margins, but counter examples were equally abundant. Bias index analysis indicated that dendritic arbors were generally unaffected by the presence of a nearby blob margin. Scanning a large number of impregnated arbors indicated that at least half of the population of blob‐related neurons had dendrites in both blob and interblob territory.Under the conditions of free dendritic penetration of blob margins, the sole factor that determines the level of blob/interblob mixing appears to be the relationship between blob size and the dendritic spread of blob neurons. Interestingly, in both the marmoset and squirrel monkeys this size ratio is similar despite a large difference in their cortical surface area. Thus, it is hypothesized that blob size is optimally matched to the dendritic span so as to create a smooth transition of dendritic sampling from blob to interblob‐related processing streams.
Small‐field neurons associated with oculomotor and optomotor control in muscoid flies: Functional organization
Authors: Gilbert Cole , Strausfeld Nicholas J. 
Published: January 2005

AbstractIn fleshflies, Sarcophaga bullata, intracellular recording and Lucifer yellow dye‐filling have revealed small‐field elements of sexually isomorphic retinotopic arrays in the lobula and lobula plate, the axons of which project to premotor channels in the deutocerebrum that supply head‐turning and flight‐steering motor neurons. The dendrites of the small‐field elements visit very restricted oval areas of the retinotopic mosaic, comprising fields that are typically 6–8 input columns wide and 12–20 high. Their physiologically determined receptive fields are also small, typically 20° or less in diameter. The neurons are hyperpolarized in stationary illumination and are transiently depolarized by light OFF and to a lesser degree by light ON. Motion of a striped grating elicits a periodic excitation at the fundamental or second harmonic of the stimulus temporal contrast frequency. The arrangement of these elements in retinotopic arrays with their small receptive fields and flicker‐sensitive dynamic properties make these neurons well suited for the position‐dependent, direction‐insensitive detection of small objects in the fly's visual field, which, is known to drive fixation and tracking.
Organization of inferior olivary projections to the flocculus and ventral paraflocculus of the rat cerebellum
Authors: Ruigrok T. J. H. , Osse R.‐J. , Voogd J. 
Published: January 2005

AbstractThe climbing fiber projection to the rat flocculus and adjacent ventral paraflocculus was investigated by using Phaseolus vulgaris‐leucoagglutinin as an anterograde and horseradish peroxidase as a retrograde tracer.Large injections of horseradish peroxidase in the flocculus and ventral paraflocculus indicated that the climbing fibers to this region are derived exclusively from any of the following contralateral olivary regions: the dorsal cap of Kooy, the ventrolateral outgrowth, the caudal half of the ventral leaf of the principal olive near its lateral bend, and the rostral pole of the medial accessory olive. Subsequent anterograde and retrograde studies with small injections demonstrated that the latter area projects to the C2 zone, which runs caudally in the ventral paraflocculus and enters the caudalmost aspect of the flocculus. The ventral leaf of the principal olive is connected to a D zone in the cerebellar hemisphere and paraflocculus, which, upon entering the ventral paraflocculus, divides into a caudal and rostral strip, termed FD and FD′, respectively. The dorsal cap and the ventrolateral outgrowth each project to two distinct zones in the flocculus and part of the ventral paraflocculus. Two floccular zones, which are continuous with the parafloccular FD and FD′ zones, receive their climbing fibers from the ventrolateral outgrowth. Two other zones, (FE and FE′) receive their climbing fibers from the dorsal cap. The FE′ zone is found at the rostral pole of the flocculus and is followed caudalwards by the FD′, FE, FD, and C2 zones, respectively. The rostromedial part of the dorsal cap is connected to the continuation of the FE zone into the ventral paraflocculus.The observation that the dorsal cap and the Ventrolateral outgrowth are both connected to a set of two alternating zones of floccular/ventral parafloccular Purkinje cells is in agreement with recent studies in the rabbit, and suggests that these zones reflect functionally distinct and discrete units related to specific aspects of visuomotor control.
Repetitive firing properties in subpopulations of the chick Edinger Westphal nucleus
Authors: Fujii Joanne T. 
Published: January 2005

AbstractThe avian Edinger Westphal nucleus, through the ciliary ganglion, controls accommodation, iris constriction, and blood flow through the choroid. In live brainstem slices, the nucleus is easily identifiable as an olive‐shaped cluster of neurons dorsal to the oculomotor nerve and nucleus. Intracellular recordings from neurons in the nucleus identified two classes of responses to sustained (300 to 500 ms) injections of depolarizing current. One set of cells fired action potentials for the duration of the pulse while a second set of cells fired action potentials only transiently, during the first 50 to 100 ms, after which they remained silent regardless of the size of the depolarization.Intracellular recordings followed by injections of the fluorescent dye lucifer yellow revealed that repetitively firing cells were located in the lateral half of the nucleus while non‐repetitively or transiently firing cells were located in the medial half. These locations correspond to different Edinger Westphal subdivisions which have distinct inputs and target populations. The varying firing patterns are discussed with reference to the known functions of the subdivisions in which they occur.Replacement of calcium by magnesium in the extracellular medium had no effect on the number of action potentials fired by non‐repetitively firing cells, suggesting that a calcium‐activated potassium current is not responsible for suppressing repetitive firing in these cells. In contrast, in repetitively firing cells removal of extracellular calcium increased the frequency of action potential discharge and decreased the amplitude of afterhyperpolarizations following single action potentials. Addition of cadmium to the bath medium had similar effects. This suggests the presence of a significant calcium‐activated potassium current and involvement of this current in regulating the frequency of action potential discharge.
Distribution of substance P‐immunoreactive elements in the preoptic area and the hypothalamus of the rat
Authors: Larsen Philip J. 
Published: January 2005

AbstractThe localization and morphology of neurons, processes, and neuronal groups in the rat preoptic area and hypothalamus containing substance P‐like immunoreactivity were studied with a highly selective antiserum raised against synthetic substance P. The antiserum was thoroughly characterized by immunoblotting; only substance P was recognized by the antiserum. Absorption of the antiserum with synthetic substance P abolished immunostaining while addition of other hypothalamic neuropeptides had no effect on the immunostaining. The specificity of the observed immunohistochemical staining pattern was further confirmed with a monoclonal substance P antiserum.The distribution of substance P immunoreactive perikarya was investigated in colchicinetreated animals, whereas the distribution of immunoreactive nerve fibers and terminals was described in brains from untreated animals. In colchicine‐treated rats, immunoreactive cells were reliably detected throughout the preoptic area and the hypothalamus. In the preoptic region, labeled cells were found in the anteroventral periventricular and the anteroventral preoptic nuclei and the medial and lateral preoptic areas. Within the hypothalamus, immunoreactive cells were found in the suprachiasmatic, paraventricular, supraoptic, ventromedial, dorsomedial, supramammillary, and premammillary nuclei, the retrochiasmatic, medial hypothalamic, and lateral hypothalamic areas, and the tuber cinereum. The immunoreactive cell groups were usually continuous with adjacent cell groups.Because of the highly variable effect of the colchicine treatment, it was not possible to determine the actual number of immunoreactive cells. Mean soma size varied considerably from one cell group to another. Cells in the magnocellular subnuclei of the paraventricular and supraoptic nuclei were among the largest, with a diameter of about 25 μm, while cells in the supramammillary and suprachiasmatic nuclei were among the smallest, with a diameter of about 12 μm.Immunoreactive nerve fibers were found in all areas of the preoptic area and the hypothalamus. The morphology, size, density, and number of terminals varied considerably from region to region. Thus, some areas contained single immunoreactive fibers, while others were innervated with such a density that individual nerve fibers were hardly discernible.During the last decade, knowledge about neural organization of rodent hypothalamic areas and mammalian tachykinin biochemistry has increased substantially. In the light of these new insights, the present study gives comprehensive morphological evidence that substance P may be centrally involved in a wide variety of hypothalamic functions. Among these could be sexual behavior, pituitary hormone release, and water homeostasis.
A projection from the parabigeminal nucleus to the pulvinar nucleus in Galago
Authors: Diamond Irving T. , Fitzpatrick David , Conley Michael 
Published: January 2005

AbstractA projection from the parabigeminal nucleus (Pbg) to the striate‐recipient zone of the pulvinar nucleus in the prosimian Galago was identified by anterograde and retrograde transport methods. In addition to the pulvinar nucleus, Pbg projections were found to terminate in layers 4 and 5 of the dorsal lateral geniculate nucleus and the central lateral nucleus. All three of these structures project to the superficial layers of the striate cortex. Similarities between the Pbg in mammals and the nucleus isthmi in nonmammals in connections and neurochemistry reinforce the idea that these two nuclei are homologous.
Metabolic correlates of optokinetic stimulation in the central visual system of the frog, Rana pipiens
Authors: Fite Katherine V. , Bengston Lynn , Taggert Gregory , Montgomery Neil , Tyler Christopher 
Published: January 2005

AbstractThe [14C]2‐deoxyglucose (2‐DG) method was used to identify those structures in the central visual system of Rana pipiens showing increased metabolic activity during binocular and monocular optokinetic stimulation at two pattern velocities (2 deg/sec and 9 deg/sec). Analysis of autoradiograms made with computer‐assisted microdensitometry and pseudocolor image‐enhancement techniques revealed that the greatest uptake of 2‐DG occurred in the pretectal region, which included the large‐celled nucleus lentiformis mesencephali (nLM), nucleus pretectalis, and pretectal gray. Both temporal‐to‐nasal (T‐N) and nasal‐to‐temporal (N‐T) directions of pattern motion were correlated with high levels of 2‐DG uptake. However, the nucleus of the basal optic root (nBOR) showed the greatest uptake of 2‐DG for the N‐T direction, which evokes little or no optokinetic (OKN) response in this species. These results suggest that the major efferent projection from nBOR to nLM may exert its greatest effect upon the ipsilateral pretectuni during N‐T stimulation.Other regions showing substantial 2‐DG uptake included a large region of the ventral thalamus, for all stimulus conditions tested, including those cell groups associated with the retinorecipient neuropil, corpus geniculatum. The pattern of uptake was less closely associated with specific parameters of optokinetic stimulation than was observed in the pretectum and accessory optic nucleus. Like nBOR, the auricular lobe of the cerebellum also showed greatest uptake of 2‐DG for the N‐T, monocular stimulus condition. The neural circuitry that underlies OKN and its directional asymmetry during monocular stimulation appears to involve a number of structures whose functional interrelationships are yet to be described.
Alpha and gamma motoneurons in the peroneal nuclei of the cat spinal cord: An ultrastructural study
Authors: Destombes J. , Horcholle‐Bossavit G. , Thiesson D. , Jami L. 
Published: January 2005

AbstractThe aim of the present study was to investigate whether ultrastructural features can be used as a guide to identify α‐ and γ‐motoneurons among the intermediate‐size neurons of the peroneal motor nuclei. The peroneus brevis and peroneus tertius muscles of adult cats were injected with horseradish peroxidase, and motoneurons labeled by retrograde axonal transport were examined by electron microscopy. In both nuclei, the distributions of cell‐body diameters, measured in the light microscope, were bimodal covering the range of 28–84 μm, with a trough around 50 μm. The sample of 25 motoneurons selected for the ultrastructural study included not only large (presumed α) and small (presumed γ) neurons but also intermediate‐size cell bodies with diameters in the 40–60 μm range. For each motoneuron, 2–5 profiles were reconstructed from ultrathin sections taken at 6–8 μm intervals. Synaptic boutons were counted and their lengths of apposition were measured. On the basis of three criteria, namely: (1) bouton types present on the membrane, (2) percentage of membrane length covered by synapses, and (3) the aspect of the nucleolus, all the examined motoneurons, including those with intermediate sizes, fell into one of two categories. Fourteen motoneurons, with cell‐body diameters in a range of 55–84 μm, were contacted by all types of boutons (mainly S‐type with spherical vesicles, F‐type with flattened vesicles, and C‐type with subsynaptic cistern); the synaptic covering of the somatic membrane was over 40% and the nucleus contained a vacuolated nucleolus. These were considered α‐motoneurons. Eleven motoneurons, with only S and F boutons, a synaptic covering under 30%, a compact nucleolus and a cell‐body diameter ranging between 28 and 50 μm, were considered γ‐motoneurons. No other combination of the three criteria was observed. These results show that unequivocal distinction of α‐ and γ‐motoneurons is possible in the peroneal nuclei, on the basis of morphological differences independent of cell‐body size.
Ontogeny of gene expression of adenosine A2 receptor in the striatum: Early localization in the patch compartment
Authors: Schiffmann S. N. , Vanderhaeghen J.‐J. 
Published: January 2005

AbstractThe ontogeny of adenosine A2 receptor mRNA and adenosine A2, binding sites distributions was studied by in situ hybridization histochemistry and receptor autoradiography in pre‐ and post‐natal rat striatum, postnatal dog striatum, and a human fetus striatum and compared to that of dopamine D1 and μ opiate receptors. The early postnatal striatum demonstrated heterogeneous distributions of adenosine A2 receptor mRNA and adenosine A2 binding sites with patches of dense labeling corresponding to dopamine D1 and μ opiate receptors enriched zones. This patchy pattern evolved to the homogeneous distribution observed in the adult. The higher intensity of adenosine A2 receptor mRNA enriched patches correspond at the microscopical level to a higher density of labeled neurons in the patches areas and also to a higher level expression per labeled patches neuron than in the matrix ones. This demonstrates for the first time that differences in patch/matrix receptor density is at least partly linked to different levels of receptor gene expression.
Ontogeny of somatostatin immunoreactivity in the cat retina
Authors: White C. A. , Chalupa L. M. 
Published: January 2005

AbstractIn the ganglion cell layer of the adult cat retina, subgroups of displaced amacrine cells and alpha ganglion cells are immunoreactive for somatostatin or a somatostatinlike substance. Both types of immunoreactive cells are found preferentially in inferior retina. We studied the development of somatostatin immunoreactivity in the prenatal and postnatal cat retina to determine how such unusual distributions of immunoreactive cells arise. Somatostatin‐immunoreactive profiles were first observed at embryonic day (E) 30, within the inner retina in a central region that included the optic disk and the area centralis. By E36, immunoreactivity had virtually disappeared from the central retina but was present throughout the periphery. The immunoreactive profiles could not be classified morphologically because of their immaturity but were most likely retinal ganglion cells, the earliest born cells of the inner retina.Of the two types of immunoreactive cell observed in the adult, the first to be recognized morphologically was the displaced amacrine cell, at E45. These cells were virtually adultlike in morphology and number by E51, two weeks before birth. In contrast, immunoreactive alpha ganglion cells were not apparent until five days after birth and did not achieve their mature numbers and immunoreactive staining characteristics until more than a month later. From the time they could initially be recognized, both immunoreactive displaced amacrine cells and alpha cells were distributed mainly in the inferior retina. A third type of somatostatin‐immunoreactive cell was transiently observed in the superior and inferior retina during prenatal and early postnatal development. These cells were characterized by granular staining in irregular shapes and few, if any, faintly stained processes. Injections of retrograde tracers into retinorecipient targets revealed that many of these cells were retinal ganglion cells. They disappeared by postnatal day 38.Our results indicate that somatostatin immunoreactivity initially follows a central‐to‐peripheral pattern of development, as is typical of other developmental events in the mammalian retina. They also indicate that the two types of somatostatin‐immunoreactive neurons present in the adult cat retina (displaced amacrine and alpha ganglion cells) attain their mature immunocytochemical properties with very different timecourses. Finally, the observation that somatostatin immunoreactivity appears transiently in the granular‐staining ganglion cells, distributed throughout the superior and inferior retina, suggests that the peptide may play a regulatory role in the development of the retina and/or retinofugal pathways.