bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cholecystokinin innervation of monkey prefrontal cortex:An immunohistochemical study
Authors: Oeth Kristen M. , Lewis David A. 
Published: January 2005

AbstractKnowledge of the circuitry of chemically identified systems in primate prefrontal cortex is limited. Although cholecystokinin is very abundant in prefrontal cortex (Geola et al.:Journal of Clinical Endocrinology and Metabolism 53(2):270–275, 1981; Taquet et al.: Neuroscience 27(3):871–883, 1988), the organization of cholecystokinin‐containing structures in primate prefrontal cortex has not been investigated. Using immunohistochemical and retrograde transport techniques, we characterized the cholecystokinin innervation of prefrontal cortex in macaque monkeys.The use of two antibodies directed against different portions of the cholecystokinin molecule revealed that distinct forms of the molecule were differentially localized in the same cortical neurons. These small, nonpyramidal cholecystokinin‐positive neurons had a variety of somal morphologies and the density of labeled cells did not differ among cytoarchitectonic regions. Labeled neurons had a distinctive laminar distribution with the greatest density of cells present in layers II‐superficial III. Labeled fibers also had a distinctive laminar pattern of distribution that differed from that of the immunoreactive neurons. In granular prefrontal cortex, terminal fields were evident in layers II, IV, and VI, with the greatest density in layer VI. Agranular area 24 exhibited a bilaminar pattern of immunoreactivity with a band in layer II and a very dense terminal field in layers V–VI.A high density of cholecystokinin‐binding sites has been found in layers III–IV of prefrontal cortex and other association areas in the monkey; this finding has been attributed to possible cholecystokinin‐containing afferents from the thalamus (Kritzer et al.: Journal of Comparative Neurology 263:418–435, 1987). The mediodorsal nucleus of the thalamus is known to be a source of afferents which terminate in layer IV of prefrontal cortex. However, combined retrograde transport and immunohistochemical techniques failed to reveal the presence of cholecystokinin‐positive neurons in the mediodorsal nucleus of the thalamus that project to prefrontal cortex. These findings, and other observations, suggest that the terminal field in layer IV is formed by descending axons that arise from cholecystokinin‐containing neurons in layers II and superficial III.This study demonstrates that the cholecystokinin innervation of prefrontal cortex has a laminar specific organization that is preserved across cytoarchitectonic regions. This distribution of immunoreactive structures suggests a distinctive role of cholecystokinin in cortical circuitry that is common to every region of prefrontal cortex.
Variability of light‐evoked response pattern and morphological characterization of amacrine cells in goldfish retina
Authors: Djamgoz M. B. A. , Spadavecchia L. , Usai C. , Vallerga S. 
Published: January 2005

AbstractAmacrine cells of the goldfish retina were characterized electrophysiologically and subsequently labelled by intracellular injection of horseradish peroxidase. An attempt was made to broaden the electrophysiological classification of the cells. Light‐evoked sustained amacrice cell responses were divided into two subtypes depending on colour opponency. Colour‐coded responses (red/depolarizing and green/hyperpolarizing) were found to arise in amacrine cells possessing highly polarized dendritic fields; the dendrites were monostratified in the proximal half (sublamina b) of the inner plexiform layer. Non‐colour‐opponent sustained responses also arose in monostratified units, but the level of dendritic ramification was in sublamina a or b (hyperpolarizing or depolarizing units, respectively). Transient (ON‐OFF) responses were associated mainly with bi‐ or multi‐stratified or diffuse amacrine cells. Some variability was observed in the sizes of the dendritic fields in different sublaminae. There was a tendency for units with brisk components of responses to be narrowly stratified in the inner plexiform layer. Some units possessed “distant” dendrites. Several aspects of structure‐function correlation in amacrine cells are discussed.
Reorganization of cranial sympathetic pathways following neonatal ganglionectomy in the rat
Authors: Smith Peter G. , Reddy Hemalatha 
Published: January 2005

AbstractPostganglionic sympathetic innervation normally is distributed ipsilaterally to lateral cranial targets. However, contralateral outgrowth occurs following unilateral ganglionectomy in neonatal rats. This study was conducted to determine the prevalence, morphological features, ganglionic derivations, and temporal sequence of sympathetic reinnervation of denervated cranial targets.Unilateral superior cervical ganglionectomy of mature rats revealed exclusively ipsilateral distributions of catecholaminergic histofluorescent fibers to orbital targets (Meibomian gland, tarsal muscle, orbital muscle, iris, ciliary body, vasculature) and the circle of Willis, with the exception of the anterior cerebral artery. In mature rats following neonatal unilateral ganglionectomy, all targets were reinnervated by fibers displaying morphologies and target relationships similar to normal innervation, but with lower densities. Acute excision of the remaining superior cervical ganglion eliminated all fibers in 7 of 8 preparations. In adult rats receiving neonatal bilateral superior cervical ganglionectomies, cerebral vasculature was reinnervated consistently, and orbital targets contained fluorescent fibers in 6 of 16 cases, indicating that reinnervation can derive from other sources when superior ganglion outgrowth is prevented. Observations in developing rats revealed fibers along the cranial portion of the contralateral optic nerve sheath at 2–3 days postganglionectomy, and within the orbit at later ages, reaching the most distal targets by 14 days.It is concluded that widespread sympathetic reinnervation of orbital and cerebrovascular targets derives primarily from the contralateral superior ganglion. Orbital ingrowth apparently originates intracranially and enters the orbit by an atypical pathway within the optic foramen.
Morphological and physiological characterization of descending ocellar interneurons in the American cockroach
Authors: Ohyama Takahiro , Toh Yoshihiro 
Published: January 2005

AbstractIn the present study two types of descending ocellar neurons have been morphologically and physiologically identified in the cockroach Periplaneta americana: a descending ipsilateral ocellar neuron (DIO‐neuron) and a descending contralateral ocellar neuron (DCO‐neuron). Both DIO‐and DCO‐neurons possess a cell body near the ocellar tract in the protocerebrum and extend dendritic processes into the ipsilateral ocellar nerve. An axon of the DIO‐neuron descends to the metathoracic ganglion, and its entire course is ipsilateral to the cell body. An axon of the DCO‐neuron crosses the median plane of the protocerebrum and descends through the contralateral ventral nerve cord to the second abdominal ganglion. Both axons possess masses of branches in each ganglion as well as in the brain. Both DIO‐and DCO‐neurons showed no spontaneous spike discharges, and responded with a few off‐spikes to ocellar illumination. They responded to various mechanical stimuli, like cereal stimulation with a train of spikes which was suppressed by ocellar illumination. Spikes of DCO‐neurons caused postsynaptic potentials and spikes in some interganglionic metathoracic interneurons, and spikes in motor nerves. These data are discussed in relation to the ocellar function of the cockroach as well as in comparison with that of other insects.
An ultrastructural and morphometric study of the effect of removal of retinal input on the development of the dorsal lateral geniculate nucleus
Authors: Brunso‐Bechtold J. K. , Vinsant S. L. 
Published: January 2005

AbstractIn normal development, cell layers in the dorsal lateral geniculate nucleus (dLGN) segregate from a relatively homogeneous cell group. If all retinal input is removed prior to this segregation, the layers fail to form. In the present study, we used ultrastructural and morphometric analyses to study dLGN development in the tree shrew following neonatal removal of retinal input. The goal of the present study was to determine whether there are differences between normal animals and enucleates in the development of dLGN cells and their interrelationships with each other and/or with the surrounding glia, which might explain the failure of cellular lamination in enucleated animals. The results indicate that although the development in enucleated animals may take place somewhat more slowly, by P90 cell size and density are not significantly different from normal. These results, coupled with the observation that the dLGN in enucleates is smaller than in normals, suggest that the removal of retinal input results in dLGN cell loss. At both the light and electron microscopic level, cells in the developing normal dLGN are arranged in bands of immediately adjacent cells. In enucleates, dLGN cells are less frequently in immediate contact and are arranged in small groups or clumps which may be separated by degenerating cells. The present data suggest that the presence of retinal input may be necessary to allow dLGN cells to maintain the intercellular relationships necessary for laminar segregation to take place.
Morphology and distribution of the glossopharyngeal nerve afferent and efferent neurons in the mexican salamander, axolotl: A cobaltic‐lysine study
Authors: Nagai Takatoshi , Matsushima Toshiya 
Published: January 2005

AbstractCobaltic‐lysine complex was used to label the afferent and efferent components of the glossopharyngeal nerve in the ganglion and brainstem of the Mexican salamander, axolotl (Ambystoma mexicanum). The distribution of afferent cell bodies in the combined glossopharyngeal‐vagus ganglion (the IX‐X ganglion) was reconstructed from serial sections, and the sizes of the cell bodies were measured. The central projection of afferents and the location of efferent cell bodies were determined by the tracer.The afferent cell bodies in the ganglion were medium‐sized (ca. 25 μm). Cell bodies with a single process were seen. The ganglion was not clearly divided into superior and inferior ganglia, as is observed in mammals and frogs, but comprised a single ganglion. Labelled cells were diffusely distributed in the rostral part of the IX‐X ganglion. A few labelled cells also were seen in the caudal part, where the vagus nerve fibers and cell bodies were mainly distributed. Double labellings of the glossopharyngeal and vagus nerves with HRP and cobaltic‐lysine demonstrated that the ganglion cells of each nerve are not clearly separated in the IX‐X ganglion. In the brainstem, the majority of afferent fibers formed thick ascending and descending limbs in the solitary fasciculus. The remaining afferent fibers formed a thin bundle in the spinal tract of the trigeminal nerve, which had a short ascending limb and a long descending limb. These two bundles had terminal areas in the ipsilateral brainstem: in the dorsal gray matter for the solitary fasciculus and in the lateral funiculus for the spinal tract of the trigeminal nerve, respectively. The cell bodies of the efferent neurons possessed developed dendritic arborizations in the ventrolateral white matter, and formed a longitudinal cell column in the ventrolateral margin of the gray matter. Thus, the glossopharyngeal nerve system in the axolotl assumes a primordial form in its ganglions, but its topographical organization in the brainstem is basically similar to that in anurans.
Organization of the visual system in larval lampreys: An HRP study
Authors: De xsMiguel Encarnación , Rodicio María Celina , Anadon Ramón 
Published: January 2005

AbstractThe organization of the visual system of larval lampreys was studied by anterograde and retrograde transport of HRP injected into the eye. The retinofugal system has two different patterns of organization during the larval period. In small larvae (less than 60–70 mm in length) only a single contralateral tract, the axial optic tract, is differentiated. This tract projects to regions in the diencephalon, pretectum, and mesencephalic tegmentum. In larvae longer than 70–80 mm, there is an additional contralateral tract, the lateral optic tract, which extends to the whole tectal surface. In addition, ipsilateral retinal fibers are found in both small and large larvae. Initially, the ipsilateral projection is restricted to the thalamus‐pretectum, but it reaches the optic tectum in late larvae. Changes in the organization of the optic tracts coincide with the formation of the late‐developing retina and consequently, the origin of the optic tracts can be related to specific retinal regions.The retinopetal system is well developed in all larvae. Most retinopetal neurons are labeled contralaterally and are located in the M2‐M5 nucleus of the mesencephalic tegmentum, in the caudolateral mesencephalic reticular area and adjacent ventrolateral portions of the optic tectum. Dendrites of these cells are apparent, especially those directed dorsally, which in large larvae extend to the optic tectum overlapping with the retino‐tectal projection.These results indicate that in lampreys, visual projections organize mainly during the blind larval period before the metamorphosis, their development being largely independent of visual function.
Specificity of initial axonal projections to embryonic chick wing
Authors: Hollyday Margaret 
Published: January 2005

AbstractAnterograde transport of HRP was used to map initial segmental projection patterns of motor and sensory axons to the chick embryo wing. At the earliest stages of innervation, before the peripheral nerves had formed, motor axons were distributed as two loosely organized sheets, one directed towards the dorsal muscle mass and the other to the ventral. Labeled axons emerging from a given spinal cord segment were distributed within the sheets in a pattern that reflected the origin of the axons along the rostro‐caudal axis of the lateral motor column. The segmental specificity of the motor projections was analyzed again after the axonal sheets had formed recognizable nerve trunks and muscle nerves. As was observed at the younger stages, axons were distributed in a pattern that was correlated with both the relative antero‐posterior (A/P) and proximo‐distal (P/D) position of the forming nerve, with cranial spinal nerves projecting to anterior and proximal limb regions. Whereas most axons emerging from a given ventral root projected in accord with what would be expected from the known adult motor pool maps, segmentally unexpected projections were frequently observed. The proportion of aberrantly projecting axons appears to be quite small, and in most embryos, it was impossible to determine whether the erroneous projections originated from unbranched axons or were collateral branches of others. The findings indicate that the initial projections of motor axons to the developing wing are patterned along the A/P axis of the wing and are largely accurate; however, the guidance processes are not sufficiently precise to exclude fibers entirely from inappropriate nerves. It is likely that later developmental processes act to fine‐tune the initial projection pattern.
Dendritic morphologies of retinal ganglion cells projecting to the nucleus of the optic tract in the rabbit
Authors: Pu Mingliang , Amthor Franklin R. 
Published: January 2005

AbstractFocal injections of Rhodamine‐latex microspheres or Fast Blue were made in the nucleus of the optic tract (NOT) of four rabbits. After survival times of 8–10 days, both dyes were retrogradely transported to medium to large sized ganglion cell somas in the retinas contralateral, but not ipsilateral, to the injected NOT. Most labelled cells were located in or near the visual streak, but a significant percentage were also found in the midperiphery of both the inferior and superior retina. One hundred fifteen labelled cells in four living supervised retinas were impaled under visual control and successfully injected with Lucifer Yellow. The dendritic arborizations of 60 of these were drawn from photographic montages for morphological identification and analysis. Nearly all the injected ganglion cells had large, relatively dense dendritic trees that stratified narrowly in the proximal inner plexiform layer. The dendritic field size and dendritic density of these cells varied with eccentricity, but at all eccentricities their anatomical characteristics closely resembled those of intracellularly stained On directionally selective ganglion cells. In three of the four experiments, a small percentage of ganglion cells were also labelled in the visual streak that had bistratified morphologies resembling those of On‐Off directionally selective ganglion cells.
GABA‐like immunoreactivity in a population of locust intersegmental interneurones and their inputs
Authors: Watson Alan H. D. , Laurent Gilles 
Published: January 2005

AbstractIntracellular labelling of locust intersegmental interneurones with lucifer yellow or horseradish peroxidase was carried out in combination with light and electron microscope immunocytochemistry by using an antibody raised against gamma amino butyric acid (GABA). Fifteen percent (four out of 27) of intracellularly stained interneurones showed GABA‐like immunoreactivity. This is in agreement with previous physiological observations that 20% of the interneurones in this population make inhibitory output conceptions in the metathoracic ganglion. GABA‐like immunoreactivity was also found in processes presynaptic to the interneurones in the mesothoracic ganglion. The presence of such immunoreactive inputs onto the intersegmental interneurones correlates well with physiological evidence that their receptive fields are in part shaped by direct input from GABA‐ergic spiking local interneurones.
Microglial cell responses in the rabbit retina following transection of the optic nerve
Authors: Schnitzer Jutta , Scherer Jürgen 
Published: January 2005

AbstractThe response of retinal microglial cells, which accompanies retrograde degeneration of ganglion cell axons and perikarya (induced by transection of the optic nerve), was studied in whole‐mounted rabbit retinae labeled enzyme‐histochemically for nucleoside diphosphatase (NDPase), which is a microglial cell marker.A few days after transection, the number of microglial cells/mm2, as well as their staining intensity, began to increase in the inner plexiform layer. The mosaic‐like distribution of the star‐shaped microglial cells present in the inner plexiform layer of a normal rabbit retina was preserved during ganglion cell degeneration. As in the normal retina, processes of individual cells never overlapped with those of neighboring cells in the inner plexiform layer because individual cells in the “degenerating” retina acquired shorter processes, i.e., the cells occupied a smaller territory compared to the normal retina.In the nerve fiber layer the number and staining intensity of NDPase‐labeled microglial cell processes (most of which are aligned in parallel with degenerating ganglion cell axons) transiently increased and returned to normal values by 5 months post‐transection.Microglial cells that are not detectably NDPase labeled in the outer plexiform layer of a normal rabbit retina acquire intense staining a few days after the nerve is cut. The functional significance of the increased NDPase activity in the plasma membrane of microglial cells during degeneration remains to be determined.
Immunoreactive GAP‐43 in the neuropil of adult rat neostriatum: Localization in unmyelinated fibers, axon terminals, and dendritic spines
Authors: DiFiglia Marian , Roberts Rosalinda C. , Benowitz Larry I. 
Published: January 2005

AbstractGAP‐43 is a neuron‐specific phosphoprotein that has been implicated in neuronal development, axonal regeneration, and synaptic plasticity. Although in mammals the caudate‐putamen is among those brain areas that retain a high content of GAP‐43 throughout life, the role of the phosphoprotein in the neostriatum is unknown. In order to understand better the possible function(s) of GAP‐43 in the adult striatum, its cellular localization was examined with immunohistochemistry at the light and electron microscopic levels by using a sheep polyclonal antibody. At the light microscopic level immunoreactive GAP‐43 was abundant throughout the neostriatal neuropil but was absent from neuronal somata. At the ultrastructural level, labeling was most prevalent in small unmyelinated axons (0.12–0.15 μm diameter). Reaction product was distributed along fibers in discrete patches about 1 μm apart and in preterminal sites from which vesicle‐filled boutons arose. Staining was also present in small (0.35 μm) axon terminals that contained round vesicles and formed asymmetric synapses, mostly with thin spines. Following unilateral cortical lesions, some degenerating cortical axons in the neostriatum exhibited GAP‐43 labeling. Unexpectedly, in normal striatum, GAP‐43 was also occasionally found in the heads of dendritic protrusions and in thin spines that received asymmetric contacts. We speculate that in the adult neostriatum, the protein may be important in the remodeling of synapses onto medium spiny neurons that involve, in part, the corticostriatal pathway.
Peptide‐immunocytochemistry of neurosecretory cells in the brain and retrocerebral complex of the sphinx moth Manduca sexta
Authors: Homberg U. , Davis N. T. , Hildebrand J. G. 
Published: January 2005

AbstractAntisera against a variety of vertebrate and invertebrate neuropeptides were used to map cerebral neurosecretory cells in the sphinx moth Manduca sexta. Intense immunoreactive staining of distinct populations of neurosecretory cells was obtained with antisera against locust adipokinetic hormone, bovine pancreatic polypeptide, FMRFamide, molluscan small cardioactive peptide (SCPB), leucine‐enkephalin, gastrin/cholecystokinin, and crustacean β‐pigment dispersing hormone (βPDH). Other antisera revealed moderate to weak staining. Each type of neurosecretory cell is immunoreactive with at least one of the antisera tested, and most of these neurons can be identified anatomically. The staining patterns provide additional information on the organization of cerebral neurosecretory cells in M. sexta. Based upon anatomical and immunocytochemical characteristics, 11 types of neurosecretory cells have been recognized in the brain, one type in the suboesophageal ganglion, and one in the corpus cardiacum. Extensive colocalization experiments show that many neurosecretory cells are immunoreactive with several different antisera. This raises the possibility that these cells may release mixtures of neuropeptides into the hemolymph, as has been demonstrated in certain other systems. The immunocytochemical data should be helpful in efforts to identify additional peptide neurohormones released from the brain of this and other insects.