bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative distribution of 3H‐GABA uptake and GAD immunoreactivity in goldfish retinal amacrine cells: A double‐label analysis
Authors: Yazulla Stephen , Studholme Keith , Wu Jang‐Yen 
Published: January 2005

AbstractThe comparative distribution of 3H‐GABA uptake and glutamic acid decarboxylase immunoreactivity (GAD‐ER) in amacrine cells of goldfish retina was studied simultaneously by using a combined autoradiographic/immunocytochemical technique in order to determine the degree of colocalization of these two markers of GABAergic neurons; 3H‐GABA was taken up most intensely by large pyriform Ab amacrine cells (3% of inner nuclear layer (INL) somata), and less intensely by smaller, polyform amacrine cells (12% of INL somata), cell bodies in the ganglion cell layer (one‐half as common as Ab cells), and cell bodies in the inner plexiform layer (very rare). GAD‐IR was observed in 25% of amacrine cells in the INL, the vast majority of which were polyform in shape, and cell bodies in the ganglion cell layer. Twice as many cells were labeled for GAD‐IR as for 3H‐GABA uptake. Of the cells that took up 3H‐GABA, colocalization of 3H‐GABA uptake and GAD‐IR was observed in 90% of the polyform amacrine cells, 80% of the cells in the ganglion cell layer, and none of the pyriform Ab amacrine cells or cells in the inner plexiform layer. We suggest that the polyform cells compose the major population of GABAergic amacrine cells in the goldfish retina, rather than the pyriform Ab cells. GABAergic displaced amacrine cells or ganglion cells are also indicated by our data. The implications of these data with regard to the physiology of the goldfish retina are discussed as well.
The sympathetic and sensory components of the caudal lumbar sympathetic trunk in the cat
Authors: Jänig W. , McLachlan Elspeth M. 
Published: January 2005

AbstractThe cell bodies of the lumbar sensory and sympathetic pre‐ and postganglionic neurons that project in the caudal lumbar sympathetic trunk of the cat have been labeled retrogradely with horseradish peroxidase applied to the central end of their cut axons. The application was made just proximal to the segmental ganglion that sends its gray rami to the L7 spinal nerve, and so identified the sympathetic outflow concerned primarily with the vasculature of the hindlimb and tail. The numbers, segmental distribution, location, and size of the labeled somata have been determined quantitatively. Labeled cell bodies were found ipsilaterally, but the segmental distributions of the different cell types were not matched. Afferent cell bodies lay in‐dorsal root ganglia Ll‐L5 (maximum L4), preganglionic cell bodies in spinal segments T10‐L5 (maximum L2/3), and postganglionic cell bodies in ganglia L2‐L5 (maximum L5). Both numbers and dimensions of labeled dorsal root ganglion cells were variable between experiments (maximum about 1,000); the majority were small relative to the entire population of sensory neurons. Labeled preganglionic cell bodies were located right across the intermediate region of the spinal cord, extending from the lateral part of the dorsolateral funiculus to the central canal. The highest density of labeled neurons lay at the border between the white and gray matter (corresponding to the intermediolateral cell column) with smaller proportions medially in L1‐L2, and laterally in caudal L4‐L5. Medial ‐ preganglionic neurons were generally larger than those lying in lateral positions. From the data, it is estimated that about 650 afferent, about 4,500 preganglionic, and some 2,500 postganglionic neurons project in each lumbar sympathetic trunk distal to the ganglion L5 in the cat.
The determination of dendrite morphology on lateral rectus motoneurons in cat
Authors: Russell‐Mergenthal Helen , McClung J. Ross , Goldberg S. J. 
Published: January 2005

AbstractPreviously developed morphometric analysis of motoneurons (Ulfhake and Kellerth, '81, J. Comp. Neurol 202: 571‐583) was applied to lateral rectus motoneurons (LRMs). Total dendrite size was approximated from a single stem dendrite measurement. Fifteen dendrites from nine LRMs of the principal abducens nucleus intracellularly stained with HRP were morphometrically analyzed. The diameters and lengths along the extent of the dendrite were measured to calculate the surface area, volume, and combined length of the process. Linear correlation of stem dendrite diameter to these size parameters produced r values of .80, .84, and .61, respectively.Although the regression lines could be used to estimate dendrite size from the stem dendrite diameter, two morphologically distinct types were found among the 83 dendrites of the nine cells. Six dendrites differed from the other 77. Therefore, these six and a representative sample of the more common dendrite (nine) were included in the measurements. The rare dendrites consistently branched at about 40 μm from the soma into a rostrally and a caudally directed secondary dendrite. The secondary dendrites branched less and reduced more in diameter by tapering. Also, these dendrites exhibited a higher than expected total dendrite size to stem diameter ratio compared to “regular” dendrites. Statistical correlations of the stem diameter to surface area or volume within each dendrite type showed clear increases in r values from those of all 15. Significant differences were found between the size parameters of the two types. These qualitative and quantitative differences should be considered in accurate motoneuron size determinations in the abducens nucleus.
Laminar and cellular localization of cytochrome oxidase in the cat striate cortex
Authors: Kageyama Glenn H. , Wong‐Riley Margaret 
Published: January 2005

AbstractCytochrome oxidase (C.O.) was histochemically localized in the cat striate cortex at the light and electron microscopic levels. The results indicate that the oxidative metabolic activity within the cat striate cortex may vary between (1) different laminae, (2) neurons and glia, (3) different neuron types, (4) dendrite and soma of the same cell, (5) different types of dendrites, (6) different segments of the same dendrite, and (7) different classes of symmetric and asymmetric axon terminals. Maximal laminar C.O. staining was localized within geniculoreceptive layer IV. Darkly reactive neurons include the large (presumed corticotectal) pyramids of layer V, and various classes of large and medium‐sized presumed GABAergic nonpyramidal cells sparsely distributed throughout layers II–VI. The small and medium‐sized pyramids of layers II, III, V, and VI, as well as many of the smaller presumed GABAergic neurons, were only lightly or moderately reactive. The darkly reactive neurons tended to be those that received convergent or proximally localized asymmetric axosomatic synapses, implying that they are strongly driven by excitatory synaptic input. The darkly reactive nonpyramids resembled those that form GAD+, symmetric axosomatic synapses with pyramidal cells. The dark reactivity of the symmetric synaptic terminals indicates that they mediate strong inhibition of neuronal discharge. The dark reactivity of a class of large asymmetric terminals in layer N is likely to represent highly active geniculocortical terminals. The predominant distribution of elevated C.O. reactivity in dendrites is correlated with reported sites of (1) convergent excitatory synaptic input, (2) maximal field potentials, (3) highly active ion transport, and (4) Na+,K+‐ATPase.
Connections of the pigeon dorsomedial forebrain studied with WGA‐HRP and 3H‐proline
Authors: Casini Giovanni , Bingman Verner P. , Bagnoli Paola 
Published: January 2005

AbstractThe afferent‐efferent connections of the pigeon dorsomedial forebrain, which is composed of the “hippocampus” (Hp) and “parahippocampus” (APH), presumed homologues of the mammalian hippocampal complex, were studied. Afferent projections were identified by wheat germ agglutininconjugated horseradish peroxidase (WGA‐HRP) and efferent projections were identified by 3H‐proline and WGA‐HRP.In addition to identified intrinsic connections within Hp and APH, both Hp and APH were found to be in receipt of ipsilateral forebrain afferents from each other, the hyperstriatum accessorium, nucleus of the diagonal band, nucleus taeniae, and area corticoidea dorsolateralis. Only Hp received input from the contralateral Hp while only APH received input from the ipsilateral hyperstriatum dorsale and archistriatum, pars ventralis. Both Hp and APH received ipsilateral diencephalic afferents from the nucleus mamillaris: lateralis, stratum cellulare internum, nucleus lateralis hypothalami, and nucleus paramedianus internus thalami. Only APH received bilateral input from the nucleus superficialis parvicellularis (this nucleus may send a small projection to Hp) and nucleus dorsolateralis anterior thalami, pars medialis, and an ipsilateral projection from the nucleus subrotundus. Brainstem afferents to Hp and APH included ipsilateral projections from the area ventralis (Tsai) nucleus reticularis pontis oralis, nucleus raphes, nucleus subceruleus dorsalis, and nucleus centralis superior of Bechterew, and bilateral projections from the nucleus linearis caudalis and locus ceruleus, of which the nucleus subceruleus dorsalis, nucleus centralis superior of Bechterew, and locus ceruleus projected to APH only.Forebrain efferents from both Hp and APH were found to project ipsilaterally to the septum, the area of the fasciculus diagonalis Brocae, nucleus taeniae, and area corticoidea dorsolateralis. Only Hp appeared to send efferents to the contralateral septum and Hp, while only APH sent efferents to the hyperstriatum dorsale and the archistriatum. A hypothalamic projection from Hp and APH was found to partially terminate near the nucleus mamillaris lateralis. At the level of pathway connections, the results demonstrate a striking similarity between the avian dorsomedial forebrain and the dorsomedial cortex of reptiles and the mammalian hippocampus.
Morphology and physiology of the brainstem nuclei controlling the electric organ discharge in mormyrid fish
Authors: Grant K. , Bell C. C. , Clausse S. , Ravaille M. 
Published: January 2005

AbstractThe motoneurons to the mormyrid electric organ are driven from the medullary relay nucleus. This nucleus is in turn innervated by an adjacent cell group, nucleus C. The goals of this study were to characterize the morphology and physiology of neurons in these two nuclei, and to test the hypothesis that nucleus C is the command nucleus responsible for initiating the electric organ discharge. Medullary relay neurons and nucleus C neurons were recorded intracellularly and labeled with horseradish peroxidase.Medullary relay neurons have a richly branched dendritic arborization, Confined mainly to the nucleus itself, and somatosomatic, dendrosomatic, and presynaptic dendro‐axonal gap junctions have been observed. Medullary relay neuron axons descend to the spinal cord without branching.Nucleus C dendrites extend far into the ventral reticular formation. Axons of nucleus C neurons have one branch that ramifies densely within the medullary relay nucleus, forming large club endings on the medullary relay neuron soma. Two additional branches project bilaterally toward the bulbar command associated nuclei.Both medullary relay neurons and nucleus C neurons fire a double action potential that precedes each electric organ discharge. Activity in nucleus C precedes that in the medullary relay nucleus by 100–300 μsec. Postsynaptic activity is recorded in nucleus C neurons but not in medullary relay neurons. Hyperpolarization of a single nucleus C neuron can lower the frequency of the electric organ discharge.Both morphological and physiological data indicate that nucleus C is an integrating center where the electric organ command is initiated.
Sensory neurons supplying touch domes near the body midlines project bilaterally in the thoracic spinal cord of rats
Authors: Smith Carolyn L. 
Published: January 2005

AbstractSensory neurons that project bilaterally to laminae III‐V of the dorsal horns in the thoracic spinal cord of rats were described in a previous anatomical study. The electrophysiological experiments reported here show that these neurons innervate skin near the dorsal and ventral midlines.Three series of experiments were undertaken: (1) the regions of skin supplied by subdivisions of thoracic nerves were mapped by recording from the subdivisions while mechanically stimulating the skin; (2) subdivisions containing the axons of contralaterally projecting sensory neurons were identified by antidromic activation from the contralateral dorsal horn; (3) the receptive fields of individual sensory neurons and dorsal horn neurons were characterized by single‐unit recording methods.Contralaterally projecting sensory neurons had axons in subdivisions of the thoracic nerves that supply skin adjacent to the body midlines. Their receptive fields were located near the dorsal or ventral midline but did not extend onto the contralateral side of the body. Most of the neurons were slowly adapting “type I” units supplying touch domes. Dorsal horn neurons receiving input from contralateral sensory neurons had receptive fields that overlapped the dorsal or ventral midline. This bilateral representation of skin near the midlines may be important for the fusion of the sensory maps of the right and left sides of the body.
Intrinsic connections of the retrohippocampal region in the rat brain. II. The medial entorhinal area
Authors: Köhler Christer 
Published: January 2005

AbstractThe present study describes the efferent projections and terminal distributions within the retrohippocampal region of individual layers of the rat medial entorhinal area (MEA) as studied by the methods of anterograde transport of the lectin Phaseolus vulgaris leucoagglutinin (PHA‐L) and retrograde transport of the fluorescent dye Fast Blue (FB). Analysis of the PHAL injections that were relatively well restricted to single layers of the MEA reveals very sparse projections to the parasubiculum, presubiculum, and subiculum, while numerous projections within the MEA are found. The course and the termination of the intra‐entorhinal projections differ depending upon the particular layer under study, and marked differences are found between the deep and the superficial layers in terms of the divergence of their respective projections. However, the general intra‐entorhinal orientation of these projections is essentially the same for all layers: longitudinal with a slightly oblique course, such that at ventral levels the center of a particular terminal field is always located lateral ‐to the center of the respective PHA‐L injection.PHA‐L injections into layer II label axons running horizontally within this layer as well as within the deep part of layer I, and PHA‐L injections into the medial sector of layer II reveal horizontal projections that innervate most of the second layer. The horizontal projections of layer III are more restricted than those of layer II but both layer U and III have prominent longitudinal projections directed ventrally. From layers II and III, numerous axons project to the deep layers (IV‐VI) probably en route to extra‐entorhinal structures, since no major terminal fields were detected in the deep layers.The PHA‐L and the FB experiments show that the deep layers (in particular IV and VI) have far more divergent intra‐entorhinal projections than have layers II and III. PHA‐L injections into layers IV, V, and VI reveal widespread efferent projections to all of the more superficially located layers of the MEA in addition to projections to the Iateral EA. The retrograde transport studies show that layers IV and VI are the major sources of these divergent projections and that cells situated throughout the entire medial to lateral width of these layers project to every sector of the retrohippocampal region.Taken together, the findings of the present experiments suggest that (1) all layers of the MEA have longitudinal projections, directed primarily toward the ventral (or temporal) part of this cortex, (2) the projections of layers II and III are relatively restricted compared of the deeper layers, and (3) the deep layers (in particular IV and VI) have highly divergent projections such that they reach most parts of layers II and III throughout the longitudinal axis of the MEA, in addition to their innervations of the lateral EA and to some degree the para‐ and presubiculum.
Freeze‐fracture study of the large myelinated club ending synapse on the goldfish Mauthner cell: Special reference to the quantitative analysis of gap junctions
Authors: Tuttle Rebecca , Masuko Sadahiko , Nakajima Yasuko 
Published: January 2005

AbstractThe large myelinated club endings (LMCEs) of primary eighth nerve afferents form mixed synapses on the lateral dendrite of the giant Mauthner cell. The double replica freeze‐fracture technique was employed to examine the intramembrane fine structure of these LMCE synapses. Morphological correlates of both chemical and electrical transmission were found at the LMCE synapses. Electrical synaptic junctions, or gap junctions, were located over much (10‐20%) of the synaptic contact. These were seen in both preand postsynaptic membrane as tightly packed P face particle aggregates and corresponding aggregates of E face pits. Specializations characteristic of chemical synaptic junctions were most prominent at the periphery of the synaptic contact. These specializations consisted of postsynaptic E face particle aggregates which were subjacent to presynaptic active zones. The active zones were distinguishable as regions with an increased density of large particles and vesicle attachment sites represented by P face depressions and E face protuberances.Quantitative analysis of gap junction particle (connexon) number at five LMCEs revealed 24,000‐106,000 connexons per LMCE. Comparison with data from electrophysiological studies of single LMCEs indicates that only a small fraction of the connexon channels are open at any given time during electrotonic transmission at an LMCE synapse.
Differential effect of visual deprivation on cytochrome oxidase levels in major cell classes of the cat LGN
Authors: Kageyama Glenn H. , Wong‐Riley Margaret 
Published: January 2005

AbstractCytochrome oxidase histochemistry was used to examine the effects of visual deprivation on the development of neurons in the lateral geniculate nucleus of the kitten. Early postnatal monocular suture results in a decrease in reactivity within the neuropil of visually deprived binocular laminae A, Al, magnocellular C, and medial interlaminar nucleus. Within these regions, monocular suture has a greater effect on the relative numbers of, and the growth of darkly reactive (normally large), presumed Y‐cells than on other less reactive geniculate neuronal classes. The decreases in the reactivity of the neuropil may be attributed to the decreases in the number of mitochondria, the number of darkly reactive mitochondria, and/or the number of darkly reactive mitochondria localized within dendrites. Although all classes of dendrites appear to be adversely affected, the decrease in C.O. reactivity was most dramatic within the presumed proximal dendrites of class 1 Y‐cells. These dendrites were identified by the type of synaptic contacts they formed with retinal terminals (Rapisardi and Miles, '84, J. Comp. Neurol. 223:515‐534; Wilson et al., '84, Proc. R. Soc. Lond. [Biol.] 221:411‐436). As with Y‐cells, the effects of monocular suture on the large darkly reactive cells were not as dramatic at sites where binocular interactions were either absent or where they had been experimentally eliminated. Based on the present and previously reported findings from several laboratories, it is likely that the selective physiological and morphological effects of monocular suture on Y‐cells are accompanied by metabolic deficits involving both dendrites and perikarya. These effects appear to be due more to binocular interactions than to visual deprivation per se.
Distribution of GABA‐like immunoreactivity in the brain of the honeybee
Authors: Schäfer Sabine , Bicker Gerd 
Published: January 2005

AbstractThe distribution of GABA‐like immunoreactivity in the brain of the honeybee was investigated with antisera generated against GABA protein conjugates. The binding of the antisera in paraffin serial sections was studied with the peroxidase‐antiperoxidase method. GABA‐like immunoreactive fibers appeared in all main neuropile areas. The staining of the optic lobes showed pronounced stratification. The receptor cells of compound eyes, ocelli, and antennae were not labelled. Several prominent fiber tracts showed GABA‐like immunoreactivity, whereas other tracts were devoid of staining. There are no major immunoreactive commissures linking the two brain hemispheres with the exception of small commissures that bridge short distances between the β‐lobes and the antennal lobes. Several fibers in the cervical connective were also labelled; some of those may descend from the suboesophageal ganglion to the thoracic ganglia. The dense reactivity seen in the optic and antennal neuropiles implies that GABA is more important in mediating local rather than more distant neural interactions.
The architecture of nerves and ganglia of the ferret trachea as revealed by acetylcholinesterase histochemistry
Authors: Baker David G. , McDonald Donald M. , Basbaum Carol B. , Mitchell Robert A. 
Published: January 2005

AbstractThe goal of this study was to determine the architecture of the nerves and ganglia of the ferret trachea. Tracheas from four newborn ferrets and three adult ferrets were stained histochemically for acetylcholinesterase activity and analyzed in their entirety as whole mounts. The architecture consisted of one or two longitudinal nerve trunks overlying the posterior surface of the trachealis muscle, a dense plexus of nerves superficial to the trachealis muscle that interconnected these longitudinal nerve trunks, and, on the anterior surface, a plexus superficial to the submucosal glands and located between the cartilaginous rings. In addition, deep neural plexuses were associated with the trachealis muscle and with the submucosal glands. Ganglion cell bodies along the longitudinal nerve trunks were large (mean diameter ± S.E. = 34.3 ± 0.3 μm), were usually attached to the nerve trunk by a stalk, and were loosely clustered in groups of as many 38 cell bodies. By contrast, those cell bodies of the superficial muscle and gland plexuses were significantly smaller (mean diameter ± S.E. = 24.2 ± 0.3 μm), were never attached by a stalk, and were tightly clustered in ganglia of one to four cell bodies. We conclude that nerves and ganglia of the ferret trachea constitute one or two longitudinal nerve trunks containing ganglia with large cell bodies, two superficial nerve plexuses containing ganglia with small cell bodies overlying the smooth muscle and submucosal glands, respectively, and two deep nerve plexuses providing the terminal innervation to the muscle and glands.