bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cell configurations in the olfactory tubercle of the rat
Authors: Millhouse O. E. , Heimer Lennart 
Published: January 2005

AbstractThe rat olfactory tubercle was studied with the rapid Golgi method. Several distinct cell types were identified mainly on the basis of the size of their somata and the structure of their dendrites. The commonest neuron type in the tubercle is the medium sized densely spined cell. The somata of these neurons occur chiefly in the dense cell and multiform layers. They also form the cell bridges that directly link the olfactory tubercle with the nucleus accumbens and caudate‐putamen. Their dendritic trees exhibit a variety of shapes; some of them are spherical, some are bipolar, and others are asymmetrical. The axons project dorsally, deep into the multiform layer. En route they give off numerous collaterals. A large version of this cell type is the crescent cell. Other medium‐sized neurons also have somata in the dense cell and multiform layers. They include the spindle cells, so named because of the shape of their cell bodies, and the medium‐sized spine‐poor neurons. Neither of these cell types has dendritic trees that are as highly branched as those of the medium‐sized densely spined cells.There are three types of small cells; their somata occur primarily in the dense cell and molecular layers. The dwarf cells are near the pial surface, although their somata are included in the dense cell layer, and they have axons that resemble those of medium‐sized densely spined cells. The radiate cells have numerous, relatively short, spine‐free dendrites that extend out from the rounded somata in all directions. The small spine‐rich cells look like miniature versions of the medium‐sized densely spined neurons. They are frequently confined to the molecular layer.Large spine‐poor neurons, with their cell bodies located in the dense cell and multiform layers, seem to be a heterogeneous cell group since there are subtle variations in the structure of their dendrites and the shape and extent of their dendritic trees. The large, moderately spined neurons are less common than the other large cells; their somata are found in all three layers.The granule cells of the islands of Calleja make up the most homogeneous cell group. They have only a few dendrites, and these are quite thin.Except for the medium‐sized densely spined and dwarf cells, the axons of the different cell types were not very well impregnated.The different cell types in the tubercle are compared to cells in the nucleus accumbens, caudate‐putamen, and globus pallidus. The remarkable structural similarities that exist between certain cells in the tubercle and some in the basal ganglia and the direct structural continuity that occurs between these structures indicate that the olfactory tubercle, at least in part, represents a ventral extension of the caudate‐putamen and globus pallidus.
Non‐uniform postnatal growth of the cat retina
Authors: Mastronarde David N. , Thibeault Marcia A. , Dubin Mark W. 
Published: January 2005

AbstractThe distributions of alpha‐type ganglion cells in 3‐week‐old and adult cats were used to measure the increase in the distances between existing cells and thus the amount of growth in various regions of the retina. Growth shows two major non‐uniformities. (1) The area centralis is at the point of minimum growth; its area increases by only about 3% while regions near the retinal margin increase in area by about 80%. (2) The retina grows about half as much in linear extent as does the radius of the eye and thus comes to occupy a smaller fraction of the globe. Measurements of retinal dimensions indicate that both non‐uniformities also occur from birth to 3 weeks.These non‐uniformities have the following implications. (1) They would tend to elongate dendritic fields radially, in the direction of the area centralis, in central retina but perpendicular to this direction in peripheral retina. However, these asymmetries are probably not the primary reason why ganglion cells throughout the retina tend to have radially oriented dendritic fields (Leventhal and Schall, '83). (2) Greater growth in the periphery could contribute to the gradient of increasing dendritic field size from central to peripheral retina if the dendritic fields of ganglion cells passively stretched as the retina expanded. Passive stretching is not the primary determinant of dendritic extent, however, because the dendritic fields of beta‐type ganglion cells were found to grow 70% more from 3 weeks to adulthood than can be accounted for by passive stretching. (3) Greater peripheral growth steepens the central‐to‐peripheral gradient of decreasing ganglion cell density; if this trend also occurs prenatally, it could be the major factor in producing the final adult gradient.
Retinal ganglion cells in two teleost species, Sebastiscus marmoratus and Navodon modestus
Authors: Ito Hironobu , Murakami Takeshi 
Published: January 2005

AbstractDistribution patterns of ganglion cells in the retina were examined in Nissl‐stained retinal whole mounts of Sebastiscus and Navodon. The existence of area centralis in the temporal retina in both species suggests binocular vision. In Navodon, another high density area was found in the nasal retina, and a dense band of ganglion cells was observed along the horizontal axis between the two high‐density areas. There is an obvious trend for the ganglion cell size to increase as the density decreases. The total number of ganglion cells was estimated to be about 45 × 104 in Sebastiscus and 87 × 104 in Navodon, whereas the total number of optic nerve fibers was about 35 × 104 and 70 × 104, respectively.The retinal ganglion cells labeled with HRP were classified into six types according to such morphological characteristics as size, shape, and location of the soma as well as dendritic arborization pattern. Type I cells have a small round or oval soma in the ganglion cell layer and a small dendritic field in the inner plexiform layer. Type II cells are similar to type I cells, but the dendrites arborize more closely to the ganglion cell layer in the innermost region of the inner plexiform layer. Type III cells have a medium‐sized round soma in the ganglion cell layer, and the dendrites extend in an extremely wide area in the inner plexiform layer with few branches. Type IV cells have a large soma which is located in the ganglion cell layer. Dendrites emanate from the soma in all directions, branching out several times within a rather small region in the innermost part of the inner plexiform layer. Type V cells have large somata of various shapes, usually dislocated to the inner plexiform or granular layer. The dendrites extend in every direction and occupy an extremely large area in the inner plexiform layer. Type VI cells have the largest somata, which are also dislocated to the inner plexiform or granular layer. Type VI cells have a characteristic triangular or fan‐shaped dendritic field.Soma size and the axon diameter are intimately linked, that is, small somata of type I and II cells give off thin axons, and large somata of type V and VI give off thick axons. Medium‐sized somata of type III cells or large somata of type IV cells, which have rather small dendritic fields, give off medium‐sized axons. The histograms of the soma areas in the whole retina are quite similar to the histograms of the diameters of the optic nerve fibers.
Anterior thalamic afferents from the mamillary body and the limbic cortex in the rat
Authors: Seki Makoto , Zyo Katuya 
Published: January 2005

AbstractAnterior thalamic afferents from the mamillary body and the limbic cortex were studied by using single and double retrograde transport methods in the rat. The medial mamillary nucleus was divided on the basis of the cytoarchitecture into four subnuclei: the pars medialis centralis, pars medialis dorsalis, pars lateralis, and pars basalis. Extensive connections were seen between each of these subdivisions of the mamillary body and the anterior thalamic nuclei, topographically organized so that the anteromedial thalamic nucleus receives projections exclusively from the pars medialis centralis, while the anteroventral thalamic nucleus receives projections from the pars medialis dorsalis and pars lateralis. Nuclei in the dorsal half of these two mamillary subdivisions project predominantly to the medial half of the anteroventral thalamic nucleus, and those in the ventral half to the lateral half of the nucleus. The pars basalis was found to have numerous projections to the magnocellular part of the anteroventral nucleus.All limbic cortical areas send projections bilaterally to all regions of the anteromedial nucleus as well as to the parvicellular parts of the anteroventral thalamic nucleus, while the anterodorsal nucleus receives ipsilateral projections originating exclusively from the preagranular, anterior limbic, and cingular regions. The magnocellular part of the anteroventral nucleus, however, receives only ipsilateral projections from all of the limbic cortex. Some neurons in the infralimbic region also project bilaterally to all of the anterior thalamic nuclei except the anterodorsal nucleus. All of these cortical projections to the anterior thalamus originate in layers V and VI of the limbic cortex.
The effects of partial retinal lesions on activity and size of cells in the dorsal lateral geniculate nucleus
Authors: Eysel U. T. , Wolfhard U. 
Published: January 2005

AbstractThe nasal parts of the adult cat retina were photocoagulated. In the dorsal lateral geniculate nucleus (dLGN) the projection of the remaining innervation was shown by anterograde transport of 3H‐proline after eye injections. The neuronal activity was measured from single cells across the border region between innervated and deafferented parts of layer A of the dLGN contralateral to the lesions. A gradual decrease from normal light‐excitability to total inexcitability was observed over a range of 300 μm. The perikaryal cell sizes measured in the same part of the dLGN displayed a concomitant decrease. Blockage of the afferent impulses by chronic application of tetrodotoxin did not change the results, suggesting that it is the loss of connections, not the loss of activity, that produces the transneuronal atrophy in the adult cat dLGN.
Postnatal development of neurons containing choline acetyltransferase in rat spinal cord: An immunocytochemical study
Authors: Phelps P. E. , Barber R. P. , Houser C. R. , Crawford G. D. , Salvaterra P. M. , Vaughn J. E. 
Published: January 2005

AbstractA monoclonal antibody to choline acetyltransferase (ChAT) has been used in an immunocytochemical study of the postnatal development of ChAT‐containing neurons in cervical and thoracic spinal cord. Specimens from rat pups ranging in age from 1 to 28 days postnatal (dpn) were studied and compared with adult specimens (Barber et al., '84). The development of established cholinergic neurons, the somatic motoneurons and sympathetic preganglionic cells, has been described as has that of previously unidentified ChAT‐positive neurons in the dorsal, intermediate, and central gray matter.Cell bodies of somatic and visceral motoneurons contained moderate amounts of ChAT‐positive reaction product at birth that gradually increased in intensity until 14–21 dpn. The most intensely stained ChAT‐positive neurons in 1–5‐dpn specimens were named partition cells because this cell group extended from the central gray to an area dorsal to the lateral motoneurons, and thereby divided the spinal cord into dorsal and ventral halves. Partition cells were medium to large in size with 5–7 primary dendrites, and axons that, in fortuitous sections, could be traced into the ventrolateral motoneuron pools, the ventral funiculi, or the ventral commissure. Small ChAT‐positive cells clustered around the central canal and scattered in laminae III–VI of the dorsal horn were detectable at birth. These neurons were moderately immunoreactive at 11–14 dpn and intensely ChAT positive by 21 dpn. The band of ChAT‐positive terminal‐like structures demonstrated in lamina III of adult specimens (Barber et al., '84) was first visible in 11–14‐dpn specimens. By 28 dpn, both laminae I and III contained punctate bands that approximated the density of those observed in adult spinal cord.This investigation has demonstrated ChAT within individual neurons of developing spinal cord, and has identified a group of neurons, the partition cells, that exhibit intense ChAT‐positive immunoreactivity earlier than any other putative cholinergic cells in spinal cord, including motoneurons. Another important observation has been that each ChAT‐positive neuronal type achieves adult levels of staining intensity at different times during development. A likely explanation for this differential staining is that various groups of neurons acquire their mature concentration of ChAT molecules at different developmental stages. In turn, this may correlate with the maturation of cholinergic synaptic activity manifest by individual cells or groups of neurons.
The central projections of intracellularly labeled auditory nerve fibers in cats
Authors: Fekete D. M. , Rouiller E. M. , Liberman M. C. , Ryugo D. K. 
Published: January 2005

AbstractThe central projections of physiologically characterized auditory nerve fibers were studied in the cochlear nuclei of adult cats after intracellular staining with horseradish peroxidase (HRP). This technique consistently labels only the type I spiral ganglion neurons which contact inner hair cells in the cochlea (Liberman and Oliver, '84). The central axon of each type I neuron bifurcates in the cochlear nucleus to form an ascending branch and a descending branch. The characteristic frequency (CF) of a fiber corresponds to the dorsoventral position of these major branches and their collateral ramifications within the nucleus. Fibers of low CFs are distributed ventrally, and fibers of increasing CF are distributed progressively more dorsally. In some cases, the collateral branches deviate from this tonotopic arrangement, particularly in (1) the octopus cell region of the posteroventral cochlear nucleus, (2) the zone of bifurcations of the auditory nerve fibers, and (3) the anterior, dorsal, and lateral margins of the ventral cochlear nucleus. Spontaneous discharge rate (SR) is related to the complexity of the axon arbor, especially along the ascending branch. Fibers of low and medium SR exhibit more axonal branch points and longer collateral lengths than do those with high SR. Six of 37 labeled fibers fail to innervate the dorsal cochlear nucleus, a feature apparently unrelated to CF or SR.
Distribution of somatic and visceral primary afferent fibres within the thoracic spinal cord of the cat
Authors: Cervero F. , Connell Lynne A. 
Published: January 2005

AbstractTransport of horseradish peroxidase (HRP) through somatic and visceral nerve fibres was used to study the patterns of termination of somatic and visceral primary afferent fibres within the lower thoracic segments of the cat's spinal cord. A concentrated solution of HRP was applied for at least 5 hours to the central end of the right greater splanchnic nerve and of the left T9 intercostal nerve of adult cats. Some animals remained under chloralose anaesthesia for the duration of the HRP transport times (up to 53 hours) whereas longer HRP application and transport times (4–5 days) were allowed in animals that recovered from barbiturate anaesthesia.Somatic afferent fibres and varicosities (presumed terminals) were found in laminae I, II, III, IV, and V of the ipsilateral dorsal horn and in the ipsilateral Clarke's column. The Density of the somatic projection was particularly high in the superficial dorsal horn. In parasagittal sections of the cord, bundles of somatic fibres were seen joining the dorsal horn from the dorsal roots via the dorsal columns and Lissauer's tract. A mediolateral somatotopic arrangement of somatic afferent terminations was observed, with afferent fibres from the ventral parts of the dermatome ending in the medial dorsal horn and afferent fibres from the dorsal parts of the dermatome ending in the lateral dorsal horn. The total rostro‐caudal extent of the somatic projection through a single spinal nerve was found to be of 2 and 2/3 segments, including the segment of entry, the entire segment rostral to it and two‐thirds of the segment caudal to it. A lateral to medial shift in the position of the somatic projection was observed in the rostro‐caudal axis of the cord.Visceral afferent fibres and varicosities (presumed terminals) were seen in laminae I and V of the ipsilateral dorsal horn. The density of the visceral projection to the dorsal horn was substantially lower than that of the somatic projection. Visceral afferent fibres reached the dorsal horn via Lissauer's tract and joined a lateral bundle of fine fibres that run along the lateral edge of the dorsal horn. The substantia gelatinosa (lamina II) appeared free of visceral afferent fibres.These results are discussed in relation to the mechanisms of viscerosomatic convergence onto sensory pathways in the thoracic spinal cord.
Ultrastructural localization of acetylcholinesterase in substantia nigra: A comparison between rat and guinea pig
Authors: Henderson Zaineb , Greenfield Susan A. 
Published: January 2005

AbstractThe distribution and ultrastructural localization of acetylcholinesterase (AChE) was examined in the substantia nigra of rat and guinea pig. Although the pars compacta, in both species, is clearly defined when stained with thionin, there is an apparent discrepancy in the distribution of AChE at the light microscope level. In the rat substantia nigra the enzyme appears to be concentrated mainly in the pars compacta, whereas in the guinea pig the AChE seems homogenous throughout the entire substantia nigra. Ultrastructural studies, however, reveal a close correspondence in the morphology of rat and guinea pig substantia nigra. The subcellular localization of AChE is also similar. The between‐species discrepancy seen with the light microscope was attributed to relative differences in level of intensity of staining for AChE. In both rat and guinea pig, the enzyme is localized in two types of neuron and in the extracellular space. The ultrastructural distribution of AChE is discussed with reference to neurochemical studies on its release from nigral neurons.
Connections of the auditory midbrain in a teleost fish, Cyprinus carpio
Authors: Echteler Stephen M. 
Published: January 2005

AbstractCentral auditory pathways were traced in Japanese carp, Cyprinus carpio, using electrophysiological mapping and HRP tract‐tracing methods. Multiunit recordings made from the carp torus semicircularis, the major midbrain area for processing octavolateralis information, revealed a mediolateral segregation of auditory and lateral line sensory modalities. Iontophoretic injections of HRP were made into the medial torus to trace afferent and efferent projections of the carp auditory midbrain.Following unilateral HRP injections into the medial torus, retrogradely labeled neurons were observed within six nuclei of the carp medulla. Two octaval nuclei, the anterior octavus nucleus and descending octavus nucleus, contained HRP‐filled neurons. Labeled neurons were also observed within the ipsilateral superior olive, scattered among fibers of both lateral lemnisci, and bilaterally within the medullary reticular formation. In addition, bilateral retrograde cell labeling was found within a group of Purkinje‐like cells located adjacent to the IVth ventricle, just rostral to the level of the VIIIth nerve. Few labeled neurons were found within the nucleus medialis, a principal target for lateral line afferents within the medulla. At midbrain levels, retrogradely labeled neurons were observed within the contralateral torus semicircularis and the ipsilateral optic tectum. Three forebrain nuclei project to the carp auditory midbrain. Within the diencephalon, descending projections originate from the anterior tuberal nucleus, bilaterally, and from the ipsilateral central posterior thalamic nucleus. The ipsilateral caudal telencephalon also projects to the carp auditory midbrain via large multipolar neurons within area dorsalis pars centralis.Anterograde labeling of fibers and terminals revealed efferent projections of the carp auditory midbrain to the following targets: the ipsilateral superior olive, the ipsilateral medullary reticular formation, the deep layers of the optic tectum, the contralateral torus semicircularis, the anterior tuberal nucleus, and the central posterior thalamic nucleus.These results, together with recent studies of lateral line pathways in teleosts (Finger, '80, '82a), demonstrate that central auditory and lateral line pathways are anatomically distinct in the carp, at least from medullary to diencephalic levels. Furthermore, there are striking similarities in the organization of the central auditory pathways of the carp and those of amphibians and land vertebrates.
Organization of thalamic projections in the nucleus accumbens and the caudate nucleus in cats and its relation with hippocampal and other subcortical afferents
Authors: Jayaraman A. 
Published: January 2005

AbstractThe organization of thalamic projections in the nucleus accumbens (NA) and the caudate nucleus of cats and its relation to other subcortical striatal afferents Were studied with a retrograde tracing technique by use of lectin‐conjugated horseradish peroxidase.The study showed that the paraventricular and medial parafascicular nuclei (PF) of the thalamus project to the medial NA and the parataenial and medial PF project to the lateral NA. The ventral tegmental area and substantia nigra pars dorsalis (SNpd) project to medial and lateral NA. The midline thalamic nuclei, rostral intralaminar nuclei, ventroanterior nucleus, medial and lateral PF, lateral posterior complex, and nucleus limitans project to medial caudate nucleus. The most medial substantia nigra pars compacta (SNpc) and rostral SNpd project to medial caudate nucleus. The center median, ventrolateral, and the central lateral nuclei of thalamus, SNpc, and SNpd project to lateral caudate nucleus.These results suggest that the thalamic and subcortical nuclei known to connect with the limbic and frontal cortices project to NA and medial caudate nucleus. Those thalamic nuclei connected with the motor system project to lateral caudate nucleus. The hippocampus projects selectively to medial NA. The amygdala, raphe, and other mesencephalic nuclei project only to NA and medial caudate nucleus. The organization of hippocampal, amygdala, and other subcortical afferents suggests that NA and caudate nucleus can be separated into medial “limbic” and lateral nonlimbic “sensory‐motor” compartments, A brief review of the distribution pattern of some neurotransmitters, neuropeptides, and their receptors and behavior studies provides additional support to the concept that the striatum can be divided into several subcompartments.