bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cortical connections of subdivisions of inferior temporal cortex in squirrel monkeys
Authors: Weller R. E. , Steele G. E. 
Published: January 2005

AbstractPatterns of cortical connections and architectonics were used to determine subdivisions of inferior temporal (IT) cortex of squirrel monkeys. Single or multiple injections of the tracers wheat germ agglutinin‐horseradish peroxidase, Fast Blue, Diamidino Yellow, Fluoro‐Gold, and 3H‐amino acids were placed into IT cortex. Most injections were placed in caudal IT cortex in the region previously shown to receive input from the caudal subdivision of the Dorsolateral Area, DLc; additional injections were placed in more rostral IT cortex. The results indicate the presence of two major regions: a caudal region, ITC, and a rostral region, ITR. An intermediate region of cortex along the ITc−ITR border that displays some connections of ITc and some connections of ITR may be another area. ITc contains a more myelinated dorsal area, ITCd, and a larger ventral area, ITCv. Both ITCd and ITCv receive a major projection from DLC; additional input from DLR, MT, and VII; and send strong projections to ITR, the lateral bank of the superior temporal sulcus, and dorsolateral prefrontal cortex. Only ITCd has strong connections with DLR and cortex in the depths of the superior temporal sulcus, and only ITCv has connections with lateral orbital cortex. The overall pattern of connections between ITC and DLC suggests that ITC has a crude topographic organization, with dorsal cortex representing the lower field and ventral cortex representing the upper field. ITR differs from ITC by receiving little if any input from DLC; projecting to inferior temporal polar cortex, the rostral Sylvian fissure, and medial orbital cortex; and having a less distinct layer IV. Comparison of subdivisions of inferior temporal cortex defined in the present study in squirrel monkeys and those reported in other primates suggests that ITC of squirrel monkeys may correspond to area TEO of macaque monkeys.
Projections of the ventral subiculum to the amygdala, septum, and hypothalamus: A PHAL anterograde tract‐tracing study in the rat
Authors: Canteras N. S. , Swanson L. W. 
Published: January 2005

AbstractThe projections of the ventral subiculum are organized differentially along the dorsoventral (or septotemporal) axis of this cortical field, with more ventral regions playing a particularly important role in hippocampal communication with the amygdala, bed nuclei of the stria terminalis (BST), and rostral hypothalamus. In the present study we re‐examined the projection of the ventral subiculum to these regions with the Phaseolus vulgaris leucoagglutinin (PHAL) method in the rat. The results confirm and extend earlier conclusions based primarily on the autoradiographic method. Projections from the ventral subiculum course either obliquely through the angular bundle to innervate the amygdala and adjacent parts of the temporal lobe, or follow the alveus and fimbria to the precommissural fornix and medial corticohypothalamic tract. The major amygdalar terminal field is centered in the posterior basomedial nucleus, while other structures that appear to be innervated include the piriformamygdaloid area, the posterior basolateral, posterior cortical, posterior, central, medial, and intercalated nuclei, and the nucleus of the lateral olfactory tract. Projections from the ventral subiculum reach the BST mainly by way of the precommissural fornix, and provide rather dense inputs to the anterodorsal area as well as the transverse and interfascicular nuclei. The medial corticohypothalamic tract is the main route taken by fibers from the ventral subiculum to the hypothalamus, where they innervate the medial preoptic area, “shell” of the ventromedial nucleus, dorsomedial nucleus, ventral premammillary nucleus, and cell‐poor zone around the medial mammillary nucleus. We also observed a rather dense terminal field just dorsal to the suprachiasmatic nucleus that extends dorsally and caudally to fill the subparaventricular zone along the medial border of the anterior hypothalamic nucleus and ventrolateral border of the paraventricular nucleus. The general pattern of outputs to the hypothalamus and septum is strikingly similar for the ventral subiculum and suprachiasmatic nucleus, the endogenous circadian rhythm generator. © 1992 Wiley‐Liss, Inc.
Distribution of the 275 kD hair cell antigen and cell surface specialisations on auditory and vestibular hair bundles in the chicken inner ear
Authors: Goodyear R. , Richardson G. 
Published: January 2005

AbstractThe 275 kD hair cell antigen (HCA) is a protein that is specifically associated with the apical surface of sensory hair cells in the chick inner ear. A comparative study of the vestibular and auditory organs of the inner ear, using both wholemounts and cryosections double labelled for the HCA and F‐actin, reveals that two distinct types of hair cells can be distinguished on the basis of antibody staining in each of the vestibular epithelia, One type of hair cell has the HCA restricted to the base of the stereocilia bundle and is found in the striolae of the maculae and in a large, centrally located region of each ampulla. The other type of hair cell is found in the extrastriolar regions of the maculae and the peripheral regions of the ampullae and has the HCA distributed over the entire surface of the stereocilia bundle. In the basilar papilla, the auditory epithelium of the chick inner ear, the HCA is, as in the striolar regions of the maculae, restricted to the base of the hair bundles. In all sensory epithelia the HCA is also present on the apical, nonstereociliary surface of the hair cells. Ultrastructural examination of the basilar papilla and the striolar and the extrastriolar regions of the lagenar macula after staining with ruthenium red and tannic acid shows that there are four morphologically different types of interstereociliary connectors (oblique tip connectors, horizontal tip connectors, shaft connectors and basal connectors) associated with the hair bundles. Oblique tip connectors and basal connectors are found on hair cells from all regions and have a similar distribution. Horizontal tip connectors are seen only on hair cells in the basilar papilla and the striolar region of the lagenar macula. Shaft connectors extend all the way to the tips of extrastriolar hair cell bundles, but extend only a short way up the bundles of hair cells in the basilar papilla and striolar region of the lagenar macula, Immunogold labelling confirms the results obtained with immunofluorescence microscopy and demonstrates that the distribution of the HCA on the surface of adjacent stereocilia correlates closely with that of the shaft connectors; i.e., immunostaining is observed up to the tips of the extrastriolar hair cell bundles, but is restricted to the lower regions of hair cell bundles in the striolar region and basilar papilla. Ruthenium red staining of immunogold labelled preparations further substantiates this correlation between the distribution of shaft connectors and the HCA. The results suggest that the HCA may be a component of a particular type of hair cell surface specialisation that, when present on adjacent the stereocilia, forms one kind of interstereociliary cross‐link, the shaft connector. © 1992 Wiley‐Liss, Inc.
Distribution and structure of identified tonic and phasic synapses between L‐neurones in the locust ocellar tract
Authors: Littlewood P. M. Henk , Simmons Peter J. 
Published: January 2005

AbstractThe ulrastructures and distributions of the discrete anatomical synapses which constitute two distinct types of output connections made by individual ocellar L‐neurones, L1–3, are described. Outputs to neurones L4–5 are excitatory and transmit tonically, whereas reciprocal connections among the three L1–3 neurones are inhibitory and incapable of transmission for longer than a few milliseconds. The tonically transmitting synapses are located in the lateral ocellar tract and are made between the axons of L1–3, which do not receive inputs, and short branches of L4–5, which make no outputs. Each excitatory connection is composed of a few hundred discrete anatomical synapses, each characterised by a bar‐shaped presynaptic density which is 0.15–1.5 m̈m in length and associated with a large number of round synaptic vesicles. Two postsynaptic profiles are apposed to each presynaptic density. Associated with tonic synapses are abundant invaginations of the presynaptic membrane. Synapses of the reciprocal, inhibitory, phasic connections occur in the protocerebral arbors of L1–3, among numerous output synapses of these neurones. Each phasic connection is composed of a few tens of discrete anatomical synapses. Each bar‐shaped presynaptic density is associated with two postsynaptic profiles, and is 0.1–1.0 m̈m long. Compared with the tonic, excitatory connection, there are fewer vesicles and fewer invaginations of the presynaptic membrane associated with each synapse. © 1992 Wiley‐Liss, Inc.
Innervation from the claustrum of the frontal association and motor areas: Axonal transport studies in the cat
Authors: Clascá Francisco , Avendaño Carlos , Román‐Guindo Ana , Llamas Alfonso , Reinoso‐Suárez Fernando 
Published: January 2005

AbstractThe anatomical organization of the projections from the claustrum to the motor and prefrontal cortical areas of the cat's brain was investigated. Both retrograde (single horseradish peroxidase or double fluorochrome deposits in the cortex) and anterograde (peroxidase‐labeled wheat germ agglutinin deposits in the claustrum) tracing techniques were used.Within the claustrum, the neurons projecting to each sector of the frontal cortex were found to be distributed according to specific patterns of segregation and overlap. Spatial segregation was particularly marked betweenthe cell populations projecting to the various sectors of area 4. The cellsprojecting to the subareas of area 6 and prefrontal cortex displayed a lessmarked but definite segregation. The neuronal populations projecting to some sectors of areas 4, 5, and the primary somatosensory cortex known to contain homotopical representations of the body map were found intermingled in the same small claustral portions. The few double‐labeled neurons found after closely adjacent fluorochrome injections indicates that, in spite of their profuse intracortical branching, claustral axons spread little within the boundaries of a single architectonic area. Anterograde transport experiments showed that claustral fibers end primarily in layers IIIb/IV, VI, and I, whereas layer V is spared. This pattern is homogeneous throughout the frontal cortex.The possible role of the claustrum as a subcortical site for organized interactions amongst wide arrays of functionally related zones of the cerebral cortex is thereby suggested. © 1992 Wiley‐Liss, Inc.
Differential expression of GABAA/benzodiazepine receptor β1, β2, and β3 subunit mRNAs in the developing mouse cerebellum
Authors: Zdilar Darko , Luntz‐Leybman Vera , Frostholm Adrienne , Rotter Andrej 
Published: January 2005

AbstractGamma aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the mammalian cerebellum. Cerebellar granule, Purkinje, and deep nuclear neurons are known to receive GABAergic afferents. Since GABA exerts its inhibitory effects via GABA receptors, it is of interest to determine the temporal relationship between the formation of GABAergic synapses and the expression of genes coding for the GABA receptor. In a previous study, we have examined the developmental expression of binding sites for [3H] muscimol, which binds with high affinity to the β subunits of the GABAA/benzodiazepine (GABAA/BZ) receptor. In the present study, [35S]cRNA probes were used to examine the appearance and distribution of GABAA/BZ β1, β2, and β3 subunit mRNAs in the developing C57BL/6 mouse cerebellum by in situ hybridization. In the adult cerebellum, the distribution of the three subunit mRNAs was clearly different, despite considerable overlap, and their temporal expression differed throughout postnatal development. The β1 hybridization signal appeared within the cerebellar cortex during the second postnatal week as a discrete band at the interface of the molecular and granule cell layers. Grains were distributed diffusely over small densely staining cells surrounding the Purkinje cells; relatively few grains were visible over Purkinje cell bodies themselves. This distribution may reflect an association with Bergmann glia or basket cells. The β2 and β3 hybridization signals were present considerably earlier than that of the β1 mRNA. The β2 signal was present at birth in the molecular/Purkinje cell layer; as development progressed, the signal became increasingly intense over both granule and Purkinje cells. At birth, the β3 subunit mRNA was present in the external germinal and molecular layers, later becoming largely localized within the granule cell layer. Dense β2 and β3 cRNA probe labeling was present over the adult granule cell layer. Moderate levels of β2 signal were seen over Purkinje cell bodies; considerably less labeling was observed with the β3 probe. The adult distribution of β2 and β3 cRNA probes showed good spatial correspondence with the known GABAA receptor β subunit markers, [3H]‐muscimol and the mAb 62‐3G1 antibody, each being present within the granule cell layer.Our results indicate that the temporal expression of GABAA/BZ receptor β subunit messages within a given cell type may be independently regulated, and that acquisition of the β2 and β3 mRNAs occurs before these cells become integrated into mature synaptic circuits. © 1992 Wiley‐Liss, Inc.
Two distinct phases characterize maturation of neurons in the nucleus of the tractus solitarius during early development: Morphological and electrophysiological evidence
Authors: Kalia M. , Schweitzer P. , Champagnat J. , Denavit‐Saubie M. 
Published: January 2005

AbstractWe have used electrophysiology and light microscopy of intracellularly labeled neurons in the nucleus of the tractus solitarius (nTS) in brainstem slices of the newborn rat (PO to P6) to examine the functional and morphological correlation of their development. Three‐dimensional reconstruction of neurons injected intracellularly with biocytin, following electrophysiological recording, revealed a close correspondence between morphological immaturity (appearing as polarization of the dendritic tree) and the absence of a ramp‐like voltage trajectory at the offset of hyperpolarizing current injections–lA negativity (8 of the 8 cells examined showed this correlation). These morphologically polarized IA negative neurons showed preferential dendritic sprouting in two diametrically opposite poles of the perikaryon.The orientation of the polarity differed according to the rostrocaudal location of the neuron. The appearance of a polarized dendritic tree during the first (immature) phase was transient and closely coincident with IA negativity. Following the development of adult‐like electrophysiological characteristics, i.e., IA positivity, nucleus of the tractus solitarius neurons showed remarkably different morphological features (9 of 10 cells). These included a widespread branching of the dendritic tree in all directions, giving it a bushy appearance (cell body to dendrite ratio of 1:40). Numerous dendritic spines, growth cones on both dendrites and axons, and axon collateralization were present during both phases and indicate that nTS neurons during the two phases of early development demonstrate dynamic features of growth and maturation. The development of adult‐like electrophysiological characteristics, i.e., IA positivity, progressively increased in the postnatal period. During the later part of the first postnatal week, twice as many neurons showed IA positivity in days P3 to P6 as compared with days PO to P2. These results reveal the dynamic nature of neurons in the nTS during early development and illustrate the close link between morphology and functional characteristics in this region. We suggest that the establishment of adult‐like morphology can be modified by appropriate environmental clues provided to nTS neurons during the initial (immature) phase of early postnatal development. © 1993 Wiley‐Liss, inc.
Estrogen receptors in the avian brain: Survey reveals general distribution and forebrain areas unique to songbirds
Authors: Gahr Manfred , Güttinger Hans‐Rudolf , Kroodsma Donald E. 
Published: January 2005

AbstractEstrogens play an important role in the control and differentiation of species‐typical behavior and in endocrine homeostasis of birds, but the distribution and evolution of cells that contain estrogen receptors in the avian brain are poorly understood. This study therefore surveys 26 species in the avian orders Anseriformes (1 species), Galliformes (2), Columbiformes (3), Psittaciformes (1), Apodiformes (2), and Passeriformes (3 suboscines, 14 oscines). Indirect immunocytochemistry with the estrogen receptor (ER) antibody H222Spy revealed a general pattern of ER‐antibody‐immunoreactive cells (ER‐IRC) in all 26 species, with ER‐IRC in consistent, well‐defined locations in the limbic forebrain, the midbrain striatum, the hippocampus, the hindbrain, and especially in the preoptic area and the tuberal hypothalamus. For some species, the microdistribution of ER‐IRC in some of these general areas differed, such as in the hippocampus and the anterior hypothalamus of suboscine species and in the preoptic area of the Japanese quail. Brains of oscine songbirds of both sexes, unlike brains of nonsongbirds, had ER‐IRC in three specific structures of the nonlimbic forebrain: in the area surrounding the nucleus robustus archistriatalis; in the rostral forebrain; and, for all individuals, in the caudale neostriatum, including the nucleus hyperstriatalis ventrale, pars caudale (HVc). Among songbird families or subfamilies, adult males of the Estrildinae had much lower numbers of ER‐IRC in HVc than did adult males of the Fringillidae, Paridae, Sturnidae, and Ploceinae. Differences occurred, too, among closely related species: the songbird canary (Serinus canaria) had an ER‐IRC area in the rostral forebrain that was lacking in all other songbird species, including other cardueline finches. The cells with ER that are found only in the songbird forebrain but not in reptiles, nonpasserine birds, and nonoscine passerine birds very likely coevolved with steroid‐dependent differentiation of vocal control areas. The songbird‐specific expression of ER in the forebrain could be an example in which taxon‐specific behavior is due to taxon specific neurochemical properties of the brain. © 1993 Wiley‐Liss, Inc.
Characterization of microglial reaction after middle cerebral artery occlusion in rat brain
Authors: Morioka Takato , Kalehua Audrey N. , Streit Wolfgang J. 
Published: January 2005

AbstractWe have studied the microglial reaction that accompanies cortical infarction induced by middle cerebral artery occlusion (MCAO). Lectin histochemistry with the B4‐isolectin from Griffonia simplicifoliaas well as immunocytochemistry with a panel of monoclonal antibodies directed against major histocompatibility complex (MHC) and lymphocytic antigens were performed. Principal attention was focused on neocortical and thalamic regions, representative of primary and secondary ischemic damage, respectively. With the lectin procedure, activated microglial cells were abundant in the neocortex 24 hours after MCAO. In contrast, microglial activation in the thalamus was not apparent until day 2 after MCAO. On day 5, MHC class II antigen was expressed by reactive microglia in fiber tracts traversing the striatum, but was absent from activated microglia in the primary cortical infarction area. MHC class I and lymphocytic antigens were expressed differentially on microglia with class I antigens appearing early and lymphocytic antigens appearing late in the time course after focal ischemia. The findings are compatible with previous studies during global ischemia and confirm the early activation and the progressive nature of immunomolecule expression on activated microglia after an ischemic insult. In addition to neocortical and thalamic sites, our results showed an early microglial activation to be present also in forebrain regions outside of the middle cerebral artery (MCA) territory, such as the contralateral cortex and hippocampus. A unilateral microglial reaction was also detectable after long‐term survival (≥4 weeks) in the pyramidal tracts, as well as in the corticospinal tracts at cervical but not lumbar spinal cord levels. Ischemia‐induced neuronal damage, as evaluated by Nissl staining, was found only in cortical and thalamic regions. We conclude that the demonstration of reactive microglia indicates not only imminent ischemic neuronal damage within MCA territory but can also delineate extra‐focal disturbances, possibly reflecting subtle and transitory changes in neuronal activity. © 1993 Wiley‐Liss, Inc.
Organization of visual corticostriatal projections in the cat, with observations on visual projections to claustrum and amygdala
Authors: Updyke B. V. 
Published: January 2005

AbstractElectrophysiological mapping criteria were employed to identify visual areas 20a, 20b, 21a, 21b, PMLS, AMLS, ALLS, PLLS, DLS, VLS, and PS in the cat, and to guide placement of tracer deposits. Anterograde tracer methods were used to study the corticostriatal projections of these extrastriate visual areas. The experiments demonstrate that all 11 extrastriate areas send projections to two distinct regions within the striatum, an extensive longitudinal zone within the caudate nucleus, and a more compact region within the posterolateral putamen. Cortical visual projections to the putamen terminate in relatively compact sheets or slabs, and appear to overlap extensively, while those to the caudate nucleus are irregularly patchy and more widely dispersed. Retrograde tracer deposits into the visual recipient zone of the caudate nucleus reveal substantial convergence of other cortical inputs to this same domain. Aspects of visuotopic organization are preserved in the visual projections to both the putamen and the caudate nucleus, but unequivocal retinotopic organization could not be inferred from the available material.Ten of the eleven extrastriate visual area also project topographically onto the visual zone of the claustrum. Area PS does not appear to contribute to the corticoclaustral projections. Five of the extrastriate visual areas (ALLS, PLLS, DLS, VLS, PS) also send sparse projections to the amygdaloid complex. c 1993 Wiley‐Liss, Inc.
Anatomical and physiological study of brainstem nuclei relaying dorsal column inputs in lampreys
Authors: Dubuc Réjean , Bongianni Fulvia , Ohta Yoshihiro , Grillner Sten 
Published: January 2005

AbstractThe course and sites of termination of dorsal column fibres in the lamprey brainstem are described along with their brainstem relays projecting to reticulospinal neurons. Dorsal column fibres ascend to the brainstem level where they intermingle with cells located in the alar plate close to the obex, a location that is analogous to that of the dorsal column nucleus in other vertebrates. Some dorsal column fibres continue further rostrally where they reach the octavolateralis and octavomotorii nuclei. Finally, a small contingent of fibres reach the cerebellum. Injections of cobalt‐lysine into the posterior rhombencephalic reticular nucleus retrogradely label neurons within the dorsal column nucleus and within the octavolateralis and octavomotorii nuclei. Microstimulation of the dorsal column nucleus on either side elicits monosynaptic inhibitory responses in reticulospinal neurons while stimulation of octavolateralis and octavomotorius nuclei elicits excitation. By using intracellular recordings, it was shown that neurons within these alar plate nuclei receive monosynaptic inputs from the dorsal columns. It is thus proposed that disynaptic inputs from dorsal columns to reticulospinal neurons are relayed by these alar plate neurons: inhibition is relayed mainly by neurons in dorsal column nuclei and excitation by neurons in the octavolateralis and octavomotorii nuclei. © 1993 Wiley‐Liss, Inc.