bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spatial density and distribution of choline acetyltransferase immunoreactive cells in human, macaque, and baboon retinas
Authors: Rodieck R. W. , Marshak D. W. 
Published: January 2005

AbstractWhole‐mounted human, macaque, and baboon retinas were labelled with an antiserum to human choline acetyltransferase (ChAT), by the immunoperoxidase technique. Previous work in nonprimate species has shown that these cells correspond to the starburst amacrine cells. Labelled somata were disposed on either side of the inner plexiform layer, and their processes formed two narrow zones within it.In human retinas, the ratio of labelled somata in the ganglion cell layer (GCL) to those in the inner nuclear layer (nominal Sb/Sa ratio) was about 60/40 at all locations, similar to that found in nonprimate mammalian species. The density of labelled cells in the human GCL ranged from 1,000 to 1,150 mm−2 near the fovea to 300 to 400 mm−2 in the periphery. Labelling tended to be more erratic in macaque retinas. Nevertheless the Sb/Sa ratio was as high as 70/30 and spatial densities were similar to those of humans. The overlap factor in macaque retinas outside the nasal quadrant was about 10 at all retinal eccentricities, based upon dendritic‐field sizes from a Golgi study.About each labelled soma there was a region 20 to 120 μm in diameter in which the probability of the occurrence of other labelled somata was lower than elsewhere. No such nonrandomness was found between labeled cells in the GCL and those in the amacrine cell layer. The packing factor was about 0.3 in well‐labelled regions, independent of retinal position or spatial density. Published data on ChAT‐labelled cells in rabbit and rat show a similar value. This invariance is consistent with the hypothesis that this nonrandomness is a residual consequence of somal contiguity at an early developmental stage. © 1992 Wiley‐Liss, Inc.
Anatomy and fine structure of neurons in the deutocerebral projection pathway of the crayfish olfactory system
Authors: Mellon De Forest , Alones Vinessa , Lawrence M. David 
Published: January 2005

AbstractGolgi impregnation and neurobiotin injection were used to examine details of the neural pathways in the olfactory system of the freshwater crayfish, Procambarus clarkii. Deutocerebral projection neurons (globuli cells) were directly injected with neurobiotin. These neurons have dendritic arborizations in the ipsilateral olfactory and accessory lobes, and they project axons to the lateral protocerebrum, where they terminate in microglomeruli of the hemiellipsoid body. The axons of the deutocerebral projection neurons are readily impregnated by Golgi procedures, and they terminate as an expanded membranous knot about 5 μm in diameter. Electron microscopy on Golgi‐stained terminals has revealed that each knot makes several hundred synapses with small spine‐like or shaft‐like processes of postsynaptic neurons. Injection of neurobiotin into local interneurons of the hemi‐ellipsoid body and subsequent examination of stained preparations with the electron microscope reveals that these cells are a major postsynaptic target of the deutocerebral projection neurons. Furthermore, the local interneurons make extensive efferent synaptic connections with unidentified neurons in the terminal medulla. © 1992 Wiley‐Liss, Inc.
Callosal and superior temporal sulcus contributions to receptive field properties in the macaque monkey's nucleus of the optic tract and dorsal terminal nucleus of the accessory optic tract
Authors: Hoffmann K.‐P. , Distler C. , Ilg U. 
Published: January 2005

AbstractTo assess the functional contribution of the cortical input to the receptive field properties of nucleus of the optic tract (NOT) and dorsal terminal nucleus (DTN) neurons, a first set of experiments evaluated the response properties of NOT‐DTN cells in monkeys with split corpus callosum. With respect to visual latency, direction specificity, directional tuning width, velocity tuning, ocular dominance, and binocular interaction, they were indistinguishable from NOT‐DTN neurons in normal monkeys. However, a clear difference was found regarding the extent of the receptive fields. Whereas, in normal monkeys, NOT‐DTN receptive fields include the contralateral hemifield and the fovea as well as substantial parts of the ipsilateral visual field, receptive fields in callosum‐split monkeys stop abruptly at, or close to, the vertical O‐meridian and do not extend into the ipsilateral visual field. In addition, the location of the highest sensitivity within the receptive fields in callosum‐split monkeys is shifted away from the vertical 0‐meridian in comparison to normal animals.In a second set of experiments, we antidromically identified cortical neurons within the superior temporal sulcus that project to the NOT‐DTN. These neurons were found in area MT mostly near the border of MTp or MSTl. All of them are direction selective for ipsiversive stimulus movement, and their receptive fields extend substantially into the ipsilateral visual hemifield. Neurons with other preferred directions did not project to the NOT‐DTN.These results contribute to the explanation of the ipsiversive directional deficits in slow eye movements after cortical lesions, as well as the asymmetries in optokinetic nystagmus with hemifield stimulation after transection of the corpus callosum. The more general implication of the results is that a particular function of a cortical area can only be understood by knowing its subcortical connections. © 1992 Wiley‐Liss, Inc.
Cortical afferents to behaviorally defined regions of the inferior temporal and parahippocampal gyri as demonstrated by WGA‐HRP
Authors: Martin‐Elkins Carol L. , Horel James A. 
Published: January 2005

AbstractThe inferior temporal gyrus in the monkey appears to be unique among the many extrastriate visual cortices in its importance for normal performance of delayed match‐to‐sample, a visual memory task. However, the anatomical pathway providing visual information to this portion of the temporal lobe remains unclear. In this study, wheat germ agglutinin conjugated to horseradish peroxidase (WGA‐HRP) was injected into the anterior inferior temporal gyrus and heavy projections were found to arise in cytoarchitectural area TF of the parahippocampal gyrus, as well as moderate projections in more posterior portions of inferior temporal gyrus and perirhinal and entorhinal cortices. Subsequently, WGA‐HRP was injected into area TF, resulting in retrogradely labeled cells primarily located in the portions of area TF adjacent to the injection and also in the occipitotemporal sulcus including the ventral portion of the prestriate visual area V4. Moderate projections were found to originate from the dorsal region of area V4 in the lunate sulcus, portions of the caudal parietal lobe, the posterior bank of caudal superior temporal sulcus, and area OPT located at the tip of the superior temporal sulcus. The middle temporal gyrus, foveal prestriate cortex, and area TEO, a transitional area between temporal and occipital visual areas, were all free from retrogradely labeled cells. These latter areas are included in the well‐established anatomical system that is known to carry visual information from striate cortex through prestriate to eventually reach dorsal portions of inferotemporal cortex which is coincident with the temporal lobe visual area TE. It is suggested here that there is an additional ventral pathway into area TE as well, which includes projections through portions of the prestriate cortex, occipitotemporal sulcus, and parahippocampal gyrus, ultimately reaching the anterior inferior temporal gyrus, an area that may be specialized to hold visual information over brief periods of time. © 1992 Wiley‐Liss, Inc.
Ontogenesis of the pyramidal cell of the mammalian neocortex and developmental cytoarchitectonics: A unifying theory
Authors: Marín‐Padilla Miguel 
Published: January 2005

AbstractThe prenatal development of the mammalian neocortex has been analyzed, with the rapid Golgi method, in a variety of experimental animals (hamster, mouse, rat, and cat) and in humans. A new developmental conception of the structural organization of the mammalian neocortex is discussed. Neocortical development begins with the establishment of the primordial plexiform layer (PPL) which precedes and is a prerequisite for the subsequent formation of the cortical plate (CP). The formation of the CP occurs, in its entirety, within the PPL. During its development, three fundamental neuronal events occur: migration, early differentiation, and late maturation. All migrating neurons, travelling on radial glial fibers, reach layer I, develop an apical dendrite, and establish contacts with its elements. These newly differentiated neurons assume similar morphology resembling embryonic pyramidal cells. As such, an early differentiation stage common to all neurons of the CP is established. During the late maturation stage, all CP neurons acquire their specific phenotypic structural and functional features. Only pyramidal neurons retain and expand their original connections with layer I while other neuronal types lose these connections. The pyramidal cell is redefined in developmental terms: the neocortex's pyramidal cell is both structurally and functionally locked into position between layer I and the cortical depth of its soma. During mammalian evolution pyramidal cells are forced to structurally and functionally elongate their apical dendrite outwardly to accommodate an increasing amount of information without losing either their original anchorage to layer I or their cortical depth. This unique property of pyramidal neurons is considered to be a mammalian innovation. Based on these observations, a unifying developmental cytoarchitectonic theory applicable to all mammals is proposed. The theory considers the CP to be a mammalian innovation and to represent a single, stratified, and expanding telencephalic nucleus. The theory envisions the mammalian neocortex as an open biological system capable of progressive expansion by the recruitment and transformation of primitive neurons from upper layer II into pyramidal cells. Hence, the number of pyramidal cell strata increases over the course of mammalian phylogeny. The developmental roles of layer I in the migration of neurons, formation of the CP, unique morphology of pyramidal cells, and overall structural organization of the mammalian neocortex are emphasized. © 1992 Wiley‐Liss, Inc.
Changes in lamination and neuronal survival in the isthmo‐optic nucleus following the intraocular injection of tetrodotoxin in chick embryos
Authors: Péquignot Y. , Clarke P. G. H. 
Published: January 2005

AbstractWe have studied how the development of the isthmo‐optic nucleus (ION) is affected by electrical activity in the ION's axonal target territory, the contralateral retina. Electrical activity was blocked or reduced in the retina for various periods by tetrodotoxin injected intraocularly in different doses. The effects on the morphology of the retina appear to have been minor.During the ION's period of naturally occurring neuronal death (embryonic days 12 to 17), the injections substantially reduced this neuronal death and disrupted the development of lamination in the contralateral ION; there was also a lesser reduction in neuronal death in the ipsilateral ION. The dose of tetrodotoxin required to affect lamination was lower than that affecting neuronal death. Thus, the effects on neuronal death and on lamination were independent, since either could occur without the other. These effects were mediated by retrograde signals (probably two or more) from the eye; they occurred too early for the alternative anterograde route via the optic tectum (which projects to the ION) to be responsible.After embryonic day 17, the ION's response to intraocular tetrodotoxin changes abruptly from increased survival to total and rapid degeneration. © 1992 Wiley‐Liss, Inc.
Maintenance of targeting errors by isthmo‐optic axons following the intraocular injection of tetrodotoxin in chick embryos
Authors: Péquignot Y. , Clarke P. G. H. 
Published: January 2005

AbstractWe have studied the role of electrical activity in the elimination of axonal targeting errors, which is a normal process in brain development. The experiments were focussed on the isthmo‐optic nucleus (ION), which, in adults, projects in topographical order on the contralateral retina. During embryogenesis, however, a few isthmo‐optic neurons project to the ipsilateral retina, and many project to topographically inappropriate parts of the contralateral one; both kinds of targeting error are known to be eliminated by the deaths of the parent neurons.We injected tetrodotoxin (TTX) intraocularly at embryonic days 13 and 15 and, on the latter, applied a retrograde label to the retina of the same eye. Embryos were fixed at embryonic day 17. In some embryos, the label was a peripherally placed fleck of the carbocyanine dye “diI”; the resulting retrogradely labeled neurons in the contralateral ION were much more widely scattered in the TTX‐injected embryos than in controls (errors in topography). In other embryos, the label was a solution of rhodamine‐B‐isothiocyanate (RITC) injected into the vitreous body; this yielded several ipsilaterally labeled isthmo‐optic neurons in the TTX‐injected embryos, but virtually none in the controls. The numbers of both kinds of aberrantly projecting neuron approached those previously reported near the beginning of the ION's period of neuronal death. We conclude that electrical activity plays an important role in the elimination of axonal targeting errors in the chick embryo's isthmo‐optic system. © 1992 Wiley‐Liss, Inc.
Area 3a in the cat II. Projections to the motor cortex and their relations to other corticocortical connections
Authors: Avendaño Carlos , Isla Alberto J. , Rausell Estrella 
Published: January 2005

AbstractIt is well known that area 3a in the cat may monosynaptically influence the activity of neurons in the motor cortex. Much less information is available, however, on the anatomy of these connections. By using single or combined injections of different retrograde axonal tracers, we investigated the topography (horizontal and laminar) of area 3a neurons projecting to the motor cortex, and the anatomical relationships between these neurons and those projecting to other areas (2, 5, and SII) which, in turn, project to the motor cortex. Area 3a projects to all parts of area 4γ, to area 4δ, and to the agranular area 6 in the lateral bank of the presylvian sulcus (area 6aγ), but not to other parts of areas 4 and 6. This projection exhibits a loose topographic organization along the mediolateral dimension of area 3a, and, in many cases, arises predominantly from the rostral half of this area.Although single small injections in the motor cortex produced two or more separate patches of retrograde labeling in 3a, after simultaneous injections of fluorochromes in two separate loci there often appeared in area 3a overlapping populations of neurons which were labeled retrogradely by each of the dyes, but with very few double‐labeled neurons. In horseradish peroxidase (HRP) cases, 72% of area 3a neurons projecting to area 4γ were distributed in supragranular layers (mainly layer III), although the proportion of labeling in infragranular layers was larger when using fluorescent dyes. Double‐labeled cells predominated in infragranular layers. These results have a bearing upon the functional roles that have been attributed to area 3a, as a cortical locus involved in muscle sensation, and a cortical relay to the motor cortex of rapid feedback information from muscle activity during movement. © 1992 Wiley‐Liss, Inc.
Diencephalic projections from the superficial and deep laminae of the medullary dorsal horn in the rat
Authors: Iwata Koichi , Kenshalo Dan R. , Dubner Ronald , Nahin Richard L. 
Published: January 2005

AbstractAn important function of the medullary dorsal horn (MDH) is the relay of nociceptive information from the face and mouth to higher centers of the central nervous system. We studied the central projection pattern of axons arising from the MDH by examining the axonal transport of Phaseolus vulgaris‐leucoagglutinin (PHA‐L). Labeled axon and axon terminal distributions arising from the MDH were analyzed at the light microscopic level.After large injections of PHA‐L into both superficial and deep laminae of the MDH in the rat, labeled axons were observed in the nucleus submedius of the thalamus (SUB), ventroposterior thalamic nucleus medialis (VPM), ventroposterior thalamic nucleus parvicellularis (VPPC), posterior thalamic nuclei (PO), zona incerta (ZI), lateral hypothalamic nucleus (LH), and posterior hypothalamic nucleus (PH).Restriction of PHA‐L into only the superficial laminae resulted in heavy axon and varicosity labeling in the SUB, VPM, PO, and VPPC and light labeling in LH. In contrast, after injections into deep laminae, labeled axons were mainly distributed in ZI and PH; some were also in VPM and LH, and fewer still in PO and SUB. Varicosities in VPM, SUB, and PO were significantly larger than those in VPPC, ZI, LH, and PH. Varicosity density was highest in SUB and lowest in the VPPC.We concluded that there are two distinct nociceptive pathways, one originating from the superficial MDH and terminating primarily in the dorsal diencephalon and the second originating from deep laminae of the MDH and terminating primarily in the ventral diencephalon. We propose that in the rat, input from the deeper laminae is primarily involved in the motivational‐affective component of pain, whereas input from the superficial MDH is related to both the sensory‐discriminative and motivational‐affective component of pain. Published by 1992 Wiley‐Liss, Inc.
Localization of kynurenine aminotransferase immunoreactivity in the rat hippocampus
Authors: Du Fu , Schmidt Werner , Okuno Etsuo , Kido Ryo , Köhler Christer , Schwarcz Robert 
Published: January 2005

AbstractThe localization and distribution of kynurenine aminotransferase (KAT), the biosynthetic enzyme of the excitatory amino acid receptor antagonist, kynurenic acid, was studied in the rat hippocampal formation with immunohistochemical methods. The enzyme was found mainly in glial cells that could be distinguished as 3 types on the basis of their shapes and locations. Typically, these cells shared the morphological features of astrocytes and exhibited glial fibrillary acidic protein immunoreactivity as demonstrated by a double‐labeling technique. The distribution of KAT‐containing glial cells was heterogeneous throughout the hippocampal formation. In the hippocampus, the stratum lacunosum‐moleculare of Ammon's horn and the hilus contained a higher density of KAT‐positive glial cells than other regions, whereas the lowest density of KAT glial cells was observed in the granule cell layer of the dentate gyrus and in the stratum radiatum of CA subfields. In the subicular complex, the density of KAT‐containing glial cells was generally higher in the superficial than in the deep layer. Hippocampal neurons exhibiting KAT immunoreactivity, distinguished as nonpyramidal cells, were very few in number and mainly distributed in strata oriens and pyramidale of Ammon's horn. Substantially more KAT‐positive neurons were observed in layers II and III of the subicular complex. The organization of cellular elements containing KAT may be of relevance for the function and possible dysfunction of kynurenic acid in the rat hippocampal formation. © 1992 Wiley‐Liss, Inc.
GABAergic neurons in the mammalian inferior olive and ventral medulla detected by glutamate decarboxylase immunocytochemistry
Authors: Fredette Barbara J. , Adams Joe C. , Mugnaini Enrico 
Published: January 2005

AbstractNeurons containing glutamic acid decarboxylase (GAD) (presumed GABAergic neurons) were mapped by immunocytochemistry in the ventral medulla of rat, rabbit, cat, rhesus monkey, and human, with emphasis on the inferior olive. In all species, three categories of GABAergic neurons were identified: periolivary neurons in the gray matter and the white matter surrounding the inferior olive, internuclear neurons located in the white matter between the subnuclei of the inferior olive, and intranuclear neurons located within the olivary gray matter. The intranuclear GABAergic neurons of the inferior olive had a characteristic morphology which differed from non‐GABAergic olivary neurons; they were usually smaller, and, wherever their processes were stained, they had radiating, sparsely branching dendrites. They were also usually distinguished from the other GABAergic neurons by their smaller size. The intraolivary GABAergic neurons constituted only a minor proportion of the total olivary neuronal population, but they were concentrated in regions of the olive that varied by species. In the rat, they were situated in the rostral tip of the medial accessory olive and in the caudal subdivision of the dorsal accessory olive, while in the rabbit, they were located in the caudal two‐thirds of the medial accessory olive, in the dorsal cap, and in the ventral lateral outgrowth. Such neurons were extremely rare in the cat; only a few were found in the rostral parts of the principal olive, the medial accessory olive, and the dorsal accessory olive. In the rhesus monkey, the principal olive and the lateral region of the rostral medial accessory olive contained most of the intranuclear GABAergic neurons, but some were also present in the dorsal accessory olive. In the human, such neurons occurred in the principal olive, the dorsal accessory olive and the rostral medial accessory olive, but as in the rhesus monkey, most were observed in the principal olive. © 1992 Wiley‐Liss, Inc.
Afferent projections to the cholinergic pedunculopontine tegmental nucleus and adjacent midbrain extrapyramidal area in the albino rat. I. Retrograde tracing studies
Authors: Steininger Teresa L. , Rye David B. , Wainer Bruce H. 
Published: January 2005

AbstractThe afferent connections of the pedunculopontine tegmental nucleus (PPT) and the adjacent midbrain extrapyramidal area (MEA) were examined by retrograde tracing with wheat germ agglutinin‐conjugated horseradish peroxidase (WGA‐HRP). Major afferents to the PPT originate in the periaqueductal gray, central tegmental field, lateral hypothalamic area, dorsal raphe nucleus, superior colliculus, and pontine and medullary reticular fields. Other putative inputs originate in the paraventricular and preoptic hypothalamic nuclei, the zona incerta, nucleus of the solitary tract, central superior raphe nucleus, substantia innominata, posterior hypothalamic area, and thalamic parafascicular nucleus. The major afferent to the medially adjacent MEA originates in the lateral habenula, while other putative afferents include the perifornical and lateral hypothalamic area, periaqueductal gray, superior colliculus, pontine reticular formation, and dorsal raphe nucleus. MEA inputs from basal ganglia nuclei include moderate projections from the substantia nigra pars reticulata, entopeduncular nucleus, and a small projection from the globus pallidus, but not the subthalamic nucleus. Dense anterograde labeling was observed in the substantia nigra pars compacta, entopeduncular nucleus, subthalamic nucleus, globus pallidus, and caudate‐putamen only following WGA‐HRP injections involving the MEA.The results of this study demonstrate that the PPT and MEA share many potential afferents. Remarkable differences were found that support distinguishing between these two nuclei in future studies regarding the functional organization of the midbrain and pons. The results, for example, confirm our previous observations that the largely reciprocal connections between the midbrain and basal ganglia distinguish the MEA from the PPT. Afferents from the lateral habenula and contralateral superior colliculus represent extensions of more traditional basal ganglion circuitry which further delineate the MEA from the PPT. The results are discussed with respect to the important role of the midbrain and pons in behavioral state control and locomotor mechanisms. © 1992 Wiley‐Liss, Inc.