bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mapping of octopamine‐immunoreactive neurons in the central nervous system of the lobster
Authors: Schneider Henning , Trimmer Barry A. , Rapus Jürgen , Eckert Manfred , Valentine Doreen E. , Kravitz Edward A. 
Published: January 2005

AbstractIt has been suggested that serotonin and octopamine serve important roles in behavioral regulation in lobsters. In this paper the locations of octopamine‐immunoreactive neurons were mapped in wholemount preparations of the ventral nerve cord of 4th stage lobster (Homarus americanus) larvae. Approximately 86 neurons were found, distributed as follows: brain, 12; circumesophageal ganglia, 2; subesophageal ganglion, 38; thoracic ganglia, 6 each; and 4th and 5th abdominal ganglia, 2 each. All the octopamine‐immunoreactive neurons are paired and located along the midline. Of the 86 neurons, 28 were identified as neurosecretory, and 26 as intersegmental ascending thoracic, ascending abdominal, or descending interneurons. The neurosecretory system is arranged segmentally and located entirely within the thoracic and subesophageal neuromeres with extensive terminal fields of endings along 2nd thoracic and subesophageal nerve roots. This set of neurons shares the features of central and peripheral endings with 2 pairs of large serotonin‐containing neurosecretory neurons found in the fifth thoracic and first abdominal ganglia. The intersegmental neurons include: (1) two cells in the brain and 2 pairs of cells in the 3rd and 4th neuromeres of the subesophageal ganglion, which project to the 6th abdominal ganglion; (2) a segmentally organized group of ascending internurons found in the subesophageal and in all thoracic ganglia; and (3) pairs of ascending interneurons found in the 4th and 5th ganglia in the abdominal nerve cord. By means of a biochemical assay, the cell bodies of octopamine‐immunoreactive neurosecretory cells in the thoracic segment of the nerve cord were found to contain 40–100 fmol of octopamine, while control neurons had none. © 1993 Wiley‐Liss, Inc.
Connections between the deutocerebrum and the protocerebrum, and neuroanatomy of several classes of deutocerebral projection neurons in the brain of male Periplaneta americana
Authors: Malun Dagmar , Waldow Ulrich , Kraus Dieter , Boeckh Jürgen 
Published: January 2005

AbstractThe topography and neuroanatomy of fibers connecting the deutocerebrum to the protocerebrum in the brain of the American cockroach Periplaneta americana were investigated by staining single or multiple deutocerebral neurons with cobalt, Lucifer Yellow, or biocytin. Five tracts are distinguished on the basis of their routes from origins in the antennal lobe to the protocerebral neuropil: the inner antenno‐cerebral tract (IACT); antenno‐cerebral tracts II, III, and IV (ACT II, III, IV), and the outer antenno‐cereral tract (OACT). These tracts are largely composed of the axons of four classes of deutocerebral projection neurons, which have been identified morphologically; the neuronal arborizations in the glomeruli of the antennal lobe and in the protocerebral projection regions have been examined. Projection neurons with processes in the inner antenno‐cerebral tract and in the antenno‐cerebral tract II each innervate a single glomerulus in the antennal lobe, and both types have terminals in the calyces of the mushroom bodies and in the lateral lobe of the protocerebrum. The axons of pheromone‐sensitive projection neurons with dendritic trees in the male‐specific macroglomerulus seem to run exclusively in the inner antenno‐cerebral tract. Subgroups of these pheromone sensitive neurons differ in relative sensitivity to the two female attractant components as well as in the arborization pattern of their dendrites in the macroglomerulus. The projection neurons of two other classes each innervate many glomeruli in the antennal lobe, those of one class sending their axons into the protocerebrum in the antenno‐cerebral tract IV and the other, in the outer antenno‐cerebral tract. The neurons of antenno‐cerebral tract IV innervate not only the mushroom body calyces and the lateral lobe but also neuropil regions not previously described in the cockroach. Neurons with axons in the outer antenno‐cerebral tract have no terminals in the calyces but innervate the lateral lobe and the neuropil surrounding the tract.The morphological findings presented here show that, in addition to the tracts previously documented in the cockroach brain, there are other, presumably olfactory, connections between the deutocerebrum and the protocerebrum. © 1993 Wiley‐Liss, Inc.
A method for unbiased and efficient estimation of number and mean volume of specified neuron subtypes in rat dorsal root ganglion
Authors: Tandrup Trine 
Published: January 2005

AbstractBy means of unbiased stereological principles and systematic sampling techniques, the number, the mean volume, and the distribution of neuron volumes of the A‐ and B‐cells of the dorsal root ganglion have been estimated. The number of each neuron type was estimated from the product of the volume of the ganglion, obtained with the Cavalieri principle on serial sections of the ganglion, and the numerical density, obtained with the Cavalieri principle on serial sections of the ganglion, and the numerical density, obtained with optical disectors on the same sections. The mean volume of the cell bodies of each type was estimated by applying the nucleator technique to the neurons sampled with the optical disectors. The precision of the estimate in each animal was evaluated on the basis of the variation between animals. An optimal sampling scheme is described by which estimates of the total number, the mean volume, and the distribution of cell body volumes can be obtained in about 8 hours.In the right fifth lumbar dorsal root ganglion taken from four mature, male Wistar rats, the mean total number of neurons was found to be 17,900. Of these, 28% were A‐cells, with a mean cell body volume of 53,400 μm3, and 70% were B‐cells, with a mean cell body volume of 8,540 μm3. There was a considerable overlap between the volume distributions of the two cell types © Wiley‐Liss, Inc.
Correlation between the receptive fields of locust interneurons, their dendritic morphology, and the central projections of mechanosensory neurons
Authors: Burrows Malcolm , Newland Philip L. 
Published: January 2005

AbstractThe relationships between the morphology and receptive fields of local and intersegmental interneurons that process mechanosensory information from a hindleg of the locust have been analysed. Sensory neurons from tactile hairs project to ventral areas of neuropil in the metathoracic ganglion where they form a 3‐dimensional somatotopic map of a hindleg. By contrast, sensory neurons from a proprioceptor at the femoro‐tibial joint (the femoral chordotonal organ) project to lateral and more intermediate areas of neuropil and have no branches in the most ventral regions of neuropil.Particular local and intersegmental interneurons respond to stimulation of specific arrays of hairs on a hindleg, or to movements of particular joints. Their receptive fields are defined, in part, by the patterns of excitatory, monosynaptic connections made by these afferents. Each interneuron has a characteristic receptive field and a characteristic morphology defined by its array of branches in the regions of neuropil containing the projections of the afferents that provide its monosynaptic inputs.Interneurons with inputs exclusively from tactile hairs have branches in the most ventral regions of neuropil, while those with exclusively proprioceptive inputs have branches only in more intermediate levels of neuropil. Interneurons with extensive receptive fields from tactile hairs also have extensive areas of branching within the ventral neuropil. Interneurons with receptive fields restricted to particular regions of the leg have branches restricted to the ventral region of neuropil containing the projections of afferents from that part of the leg. Thus, interneurons with inputs only from hairs on the tarsus have branches in the posterior region of neuropil corresponding to the projections of the tarsal afferents, while interneurons with receptive fields on the femur have branches in more anterior regions of neuropil corresponding to the projections of the femoral hair afferents. Interneurons with receptive fields on the tibia have branches in neuropil between the tarsal and femoral projections. © 1993 Wiley‐Liss, Inc.
Distribution of glial fibrillary acidic protein‐immunopositive structures in the brain of the domestic chicken (Gallus domesticus)
Authors: Kálmán Mihály , Székely Andrea D. , Csillag András 
Published: January 2005

AbstractThe present study is the first comprehensive mapping of glial fibrillary acidic protein (GFAP)‐immunopositive structures in the avian brain. Two main types of GFAP‐immunopositive elements were observed: (1) nonbranching fibers, occasionally twisted or varicose, and (2) star‐shaped cells. Long immunostained fibers orignate from the lateral ventricle to form three bundles. Fibers of the dorsal group, emanating from the dorsal/lateral corner of the ventricle, course in lateral, anterior, and ventral directions forming a semidome, which separates the outer pallial (lateral cortical) regions from the underlying striatal mass. The middle group of fibers is directed anteriorly and laterally corresponding to the laminae frontales superior and suprema. The ventral fiber bundle is conical and traverses the lobus parolfactorius, crossing also the lamina medullaris dorsalis (the latter consisting mainly of star‐shaped cells). The hippocampus, septum, and hypothalamus also contain straight radial fibers. In some areas, given their variable orientation, the fibers cannot be regarded as merely persisting radial glia. In the telencephalon, the nuclei basalis, accumbens, ectostriatum, paleostriatum primitivum, and the ventral paleostriatum are particularly rich in GFAP‐positive cells, whereas the neostriatum, hyperstriatum, and paleostriatum augmentatum are almost devoid of GFAP labelling. Certain nuclei of the thalamus and the lower brainstem are conspicuous by their low levels of GFAP immunoreactivity. The Bergmann glia were GFAP‐immunonegative.
Geometry of the representation of the visual field on the superior colliculus of the wallaby (Macropus eugenii). I. Normal projection
Authors: Mark R. F. , James A. C. , Sheng X.‐M. 
Published: January 2005

AbstractIn 13 wallabies (Macropus eugenii, the tammar), microelectrode recordings of the activity of units in the superficial layers of the superior colliculus in response to a flashing light spot were used to make a map of the spatial location of their receptive fields. This article describes the projection of a normal eye to the contralateral colliculus. Ten of the 13 animals had one rotated eye and these projections are analysed in the accompanying paper (James et al., this issue). Units responded briskly to the stimulus at light on and off and had receptive fields about 5° across. The centres of receptive fields from a regular array of recording points on the colliculus were plotted with a perimeter and fitted to a flattened representation of the colliculus according to a spline technique. The visual field of each colliculus extends from 25° ipsilateral to the vertical meridian to 120° temporal contralaterally. The lines of isoazimuth are regularly spaced and paralled and run mediolaterally on the colliculus. The horizon is represented by a line running rostrocaudally and the parallels are more widely spaced near the horizon and become compressed in the superior and inferior fields. The variation of areal magnification factor fits the distribution of density of retinal ganglion cells very well. Anisotropy of the projection means that the increased ganglion cell density of the retinal visual streak is entirely accommodated by magnification in the vertical direction, while the magnification of the azimuthal projection is equal over the whole field. No responses were recorded from the ipsilateral eye even though anatomically there is a direct retinal ipsilateral projection.
Numbers of neurons in the developing principal sensory nucleus of the trigeminal nerve: Enhanced survival of early‐generated neurons over late‐generated neurons
Authors: Miller Michael W. , Al‐Ghoul Walid M. 
Published: January 2005

AbstractThe overproduction and subsequent death of neurons is a common phenomenon in the developing vertebrate central nervous system (CNS). We tested the hypothesis that the survival of a neuronal subpopulation is related to its time of origin. Neuronal survival was examined in a well‐defined CNS structure, the principal sensory nucleus of the trigeminal nerve (PSN) of the rat. The changes in the total number of PSN neurons and in the numbers of early‐ and late‐generated neurons (i.e., neurons heavily labeled by a single injection of [3H]thymidine on G12 or G14, respectively) between gestational day (G) 16 and postnatal day (P) 10 were determined. The total number of neurons in the PSN rose prenatally to a maximum of 40,600 on G18.5. The increase in neuronal number correlates to the period of migration. More than half of the neurons that successfully migrated to the PSN were lost by P10. The patterns for the changes in the numbers of early‐ and late‐generated neurons were similar; however, there were significant differences between the two subpopulations. The maximum number of early‐generated neurons (4,250) was attained on G18.2 and subsequèntly 58.9% of these neurons were lost. In contrast, the maximum number of late‐generated neurons (5,050) was attained on G20.0 and 66.6% of these neurons were lost by P10. Therefore, it appears that the survivability of early generated neurons is greater than for late‐generated neurons. This enhanced survivability presumably results from a competitive advantage that early‐generated neurons have for forming synapses or gaining access to trophic factor(s) that are in limited supply.
Quantitative phylogenetic constancy of cerebellar purkinje cell morphological complexity
Authors: Smith Thomas G. , Brauer Kurt , Reichenbach Andreas 
Published: January 2005

AbstractGolgi‐stained material of cerebellar cortices from 17 species was examined by measuring the fractal dimensions of the borders of Purkinje cells, which is a quantitative, objective measure of morphological complexity. Nine species (from birds to man) were chosen for a comparison with ANOVA and no statistically significant differences were found in their fractal dimensions. In contrast, a wide range of differences was found in the membrane areas across species lines. The Sholl coefficient, a measure of branch formation and temination and termination away from the soma, showed no consistent pattern for each cell. We interpret our results as indicating a constancy in morphological cellular complexity of Purkinje cells during late evolutionary time. © 1993 Wiley‐Liss, Inc.
Localization of D2 dopamine receptors in vertebrate retinae with anti‐peptide antibodies
Authors: Wagner Hans‐Joachim , Luo Bao‐Guo , Ariano Marjorie A. , Sibley David R. , Stell William K. 
Published: January 2005

AbstractDopamine plays an important role in modulating various aspects of retinal signal processing. The morphology of dopaminergic neurons and its physiological effects are well characterized. Two classes of receptor molecules (D1 and D2) were shown pharmacologically to mediate specific actions, with differences between individual groups of vertebrates. In an attempt to better understand dopaminergic mechanisms at the cellular level, we used antisera against D2 receptors and investigated the localization of the dopamine D2 receptor in the retinae of rat, rabbit, cow, chick, turtle, frog, and two fish species with immunofluorescence techniques. Antisera were raised in rabbits to two oligopeptides predicted from rat D2 receptor cDNA; one specific for the splice‐variant insertion in the third cytoplasmic loop and the other directed towards the extracellular amino terminal region shared by both short and long isoforms. Preadsorption with the synthetic peptide resulted in a significant reduction of label, indicating the presence of specific binding in all species except turtle and goldfish. The pattern of labelling produced by the two antisera was essentially identical; however, the staining obtained with antiserum to the extracellular motif was always more intense. Specific staining was present in photoreceptor inner and outer segments, and in the outer and inner plexiform layers of all species. In mammals and chick, strongly fluorescent perikarya were observed in the ganglion cell layer and at the proximal margin of the inner nuclear layer. Label may be present in the pigment epithelium but could not be established beyond doubt. This pattern of labelling is in accordance with previous observations on D2 receptor localization by means of radioactive ligand binding and in situ hybridization techniques. It suggests that retinal dopamine acts as a neuromodulator as well as a transmitter. In the distal retina, it may reach its targets via diffusion over considerable distances, even crossing the outer limiting membrane; in the inner and outer plexiform layers, conventional synaptic transmission seems to coexist with paracrine addressing of more distant targets, and D2 receptors are expressed by both amacrine and ganglion cells. © 1993 Wiley‐Liss, Inc.
Corticofugal projections to the vestibular nuclei in squirrel monkeys: Further evidence of multiple cortical vestibular fields
Authors: Akbarian S. , Grüsser O.‐J. , Guldin W. O. 
Published: January 2005

AbstractSingle‐ and multiple‐unit recordings were made from nerve cells located in the different nuclei of the brainstem vestibular nuclear complex (VNC) of anaesthetized squirrel monkeys (Saimiri sciureus) by conventional sterotaxic techniques. After neurons responding to semicircular canal stimulation in a yaw, roll, or pitch direction or to otholith stimulation were identified, small amounts of retrograde tracer substances were deposited at the recording sites. Up to three different tracers were administered to different parts of the VNC in the same animal (Fast Blue, HRP‐WGA, and Rhodamine‐dextranes). After adequate survival times, the animals were sacrificed. Following histological processing, the cortical grey matter was screened systematically for cells labelled with the retrograde tracers (fluorescence microscopy or light microscopy for HRP processing). Labelled nerve cells which clearly project to the VNC directly were found predominantly in the cytoarchitectonic layer 5 of seven different cortical areas: (1) The parieto‐insular vestibular cortex PIVC, which in squirrel monkeys consists mainly of the medial area Ri and parts of the anterior area Ig; (2) area 7ant, which presumably corresponds to the macaque area 2v; (3) area 3aV, a vestibular field of area 3a; (4) the temporal area T3 bordering on area Ri; (5) the premotor area 6a; and (6, 7) the areas 6c and 23c of the anterior cingulate cortex. The PIVC, area 7ant, and area 3aV form the “inner cortical vestibular circuit” (Guldin et al.: J. Comp. Neurol. 326:375–401, '92) while the other cortical areas mentioned also have direct projections to the structures of the inner cortical vestibular circuit. It is speculated that the direct projections of the cortical vestibular structures to the brainstem vestibular nuclei regulate the vestibulo‐ocular, the vestibulo‐spinal, and the optokinetic reflexes mediated through the VNC, thus preventing counteractions of these reflexes during voluntary, goal‐directed head movements or locomotion. © 1993 Wiley‐Liss, Inc.
Local origins of some GABAergic projections to the paraventricular and supraoptic nuclei of the hypothalamus in the rat
Authors: Roland B. L. , Sawchenko P. E. 
Published: January 2005

AbstractAxonal transport and immunohistochemical methods were used to characterize the organization of glutamic acid decarboxylase‐immunoreactive (GAD‐ir) projections to the paraventricular (PVH) and supraoptic (SO) nuclei of the hypothalamus in the rat. In line with prior reports, GAD‐ir varicosities were found to be densely and quite uniformly distributed throughout the hypothalamus, including the PVH and the SO. Nonetheless, the periventricular part of the PVH was consistently found to contain a disproportionately high density of GAD‐ir elements. Small crystalline implants of the retrograde tracer, true blue, into the PVH labeled GAD‐ir cells in the anterior perifornical region, portions of the anterior hypothalamic area immediately ventral to the PVH, a region just dorsal to the rostral SO and extending caudomedially over the optic chiasm and tract, and within the anterior one‐third of the PVH itself. Because possible uptake of retrograde tracer by local dendritic processes might have yielded false positive filling of nearby GAD‐ir cells, anterograde transport, Phaseolus vulgaris‐leucoagglutinin, and combined anterograde transport‐immunohistochemical methods were used to attempt to confirm these four putative local sources of GAD‐ir inputs. Tracer injections in each of the above mentioned regions labeled sparse to moderate axonal projections to the PVH, which ramified preferentially in the parvicellular division of the nucleus. Projections to the magnocellular division of the PVH and the SO were generally sparse and inconsistently observed in this material. A variable, and generally small, proportion of anterogradely labeled axons and terminals in the PVH also displayed GAD‐ir. These results suggest that GABAergic projections to visceromotor cell types in the PVH and SO arise, at least in part, from several diffusely distributed local sources. The fact that these afferents were found to terminate preferentially in the parvicellular division of the PVH makes it likely that additional sources of GABAergic projections to the magnocellular neurosecretory system remain to be identified. Peri‐ and intranuclear GABAergic neurons could provide an intermediary by which documented (and generally inhibitory) limbic system influences on neuroendocrine function are exerted. © 1993 Wiley‐Liss, Inc.
Choline acetyltransferase immunoreactive neurons innervating labyrinthine and lateral line sense organs in amphibians
Authors: González A. , Meredith G. E. , Roberts B. L. 
Published: January 2005

AbstractThe goal of the present study was to investigate aspects of the central organization of the neurons belonging to the octavolateralis efferent system of amphibians. The perikarya of three genera, Pleurodeles, Xenopus, and Discoglossus, were located in the brainstem by applying retrograde to the appropriate cranial nerves and choline acetyltransferase immunohistochemistry was used to identify cholinergic neurons.The efferent neurons supplying lateral line (Pleurodeles, Xenopus) and labyrinthine (Pleurodeles, Xenopus, and Discoglossus) end organs were found to intermingle in a single octavolateralis efferent nucleus. The neurons lie bilateral to the labelled nerves in Pleurodeles and ipsilateral in Xenopus and Discoglossus. Separate labelling of the anterior and posterior octavus rami provided no evidence for distinct groupings of efferent neurons that could be associated with auditory and vestibular end organs. In all three species many if not all octavolateral efferent neurons displayed immunoreactivity for choline acetyltransferase. They could be distinguished from the cholinergic facial motoneurons, with which they sometimes intermingle, on the basis of either their distinctive size and shape (Pleurodeles, Xenopus) or their location (Discoglossus). Double labelling in Xenopus confirmed the cholinergic nature of the efferent neurons. © 1993 Wiley‐Liss, Inc.