bluuebunny/crossref_metadata_2025_split huggingface dataset:
Central projections of the antennal cold receptor neurons and hygroreceptor neurons of the cockroach Periplaneta americana
Authors: Nishikawa Michiko , Yokohari Fumio , Ishibashi Takaaki 
Published: January 2005

AbstractThe central projections of the cold receptor axons were examined by filling two types of cold receptive sensilla with cobalt lysine—a cold and hygroreceptive (C/H) sensillum and a cold receptive and olfactory (C/O) sensillum—on the antennae of the cockroach, Periplaneta americana L. When the dye filled a single C/H sensillum, four axons were stained. Three of these axons terminate in the ipsilateral antennal lobe, while the other branches in the ipsilateral dorsal lobe. One of the branches passed through the tritocerebrum to terminate in the suboesophageal ganglion, while the other branches end in the lobe. When a single C/O sensillum is dye filled, all axons of the four receptor neurons terminate exclusively in the ipsilateral antennal lobe. One axon from the C/H sensillum and one axon from the C/O sensillum terminate in a particular glomerulus in the ventroposterior region of the antennal lobe. Each of these axons also has a tuft in separate giomeruli situated just dorsal to the glomerulus in which both axons terminate. This set of three glomeruli have indistinct boundaries and appear to form a complex of glomeruli similar to the macroglomerular complex of male moths. Assuming modality‐specific convergence of antennal afferents, these axons appear to belong to the cold receptor neurons, and the set of glomeruli appear to function in cold reception. Two other neurons stained from C/H sensilla always terminate in theglom‐eruli distinct from the set of glomeruli mentioned earlier. These neurons are assigned to the pair of hygroreceptor neurons, and their glomeruli are thought to function in hygroreception. © 1995 Wiley‐Liss, Inc.
Spinovestibular projections in the rat, with particular reference to projections from the central cervical nucleus to the lateral vestibular nucleus
Authors: Matsushita Matsuo , Gao Xiulai , Yaginuma Hiroyuki 
Published: January 2005

AbstractProjections from the spinal cord to the vestibular nuclei were examined following injections of Phaseolus vulgaris–leucoagglutinin, cholera toxin subunit B, or biotinylated dextran at various levels of the spinal cord in the rat. Labeled terminals were abundant after injections of the tracers into the C2 and C3 segments containing the central cervical nucleus. Labeled terminals were seen in the descending vestibular nucleus and the parvocellular, magnocellular, and caudal parts of the medial vestibular nucleus throughout its rostrocaudal extent. Labeled terminals were most numerous in the lateral vestibular nucleus throughout its rostrocaudal extent. The projections from the central cervical nucleus to the vestibular nuclei were exclusively contralateral to the cells of origin because the axons of the central cervical nucleus neurons cross in the spinal cord. Following tracer injections in the cervical enlargement, many labeled terminals were seen in the magnocellular part of the medial vestibular nucleus, but a few were seen in the lateral and the descending vestibular nucleus. Injections into more caudal segments resulted in sporadic terminal labeling in the magnocellular part of the medial vestibular nucleus, the descending vestibular nucleus, and the caudal part of the lateral vestibular nucleus.The results indicate that primary neck afferent input relayed at the central cervical nucleus is mediated directly to the contralateral vestibular nuclei. It is suggested that this projection serves as an important linkage from the upper cervical segments to the lateral vestibulospinal tract in the tonic neck reflex. © 1995 Wiley‐Liss, Inc.
The glutamate‐enriched cortical and thalamic input to neurons in the subthalamic nucleus of the rat: Convergence with GABA‐positive terminals
Authors: Bevan Mark D. , Francis C. M. , Bolam J. P. 
Published: January 2005

AbstractNeurons of the subthalamic nucleus play a key role in the normal physiology and the pathophysiology of the basal ganglia. In order to understand better how the activity of subthalamic neurons and hence the output of the basal ganglia are controlled, we have reexamined the topography and examined in detail the synaptology and neurochemical nature of the two major excitatory projections to the subthalamic nucleus, that from the cortex and from the parafascicular nucleus of the thalamus. The approach was to use anterograde neuronal tracing and postembedding immunocytochemistry for amino acid transmitters.In confirmation of previous findings the cortical and thalamic projections were topographically organized, although the topography was more finely organized, and the projections more extensive, than previously demonstrated. Cortical and thalamic terminals made asymmetrical synaptic contacts with the dendrites and spines of subthalamic neurons. The thalamic terminals contacted larger postsynaptic targets, and therefore presumably more proximal regions of subthalamic neurons, than did the cortical terminals. Quantitative analysis of the postembedding immunolabelled sections revealed that the cortical and thalamic terminals were significantly enriched in glutamate‐immunoreactivity when compared to identified γ‐aminobutyric acid (GABA)‐positive terminals, supporting physiological studies that suggest that these projections use glutamate as their neurotransmitter. In addition a small population of nonanterogradely labelled terminals that formed asymmetrical synapses and were immunopositive for GABA were identified. A larger population of terminals that formed symmetrical synapses were also immunbpositive for GABA and were probably derived from the globus pallidus. The latter type of terminal was found to make convergent synaptic input with cortical or thalamic terminals on this dendrites and spines of subthalamic neurons, indicating that the “indirect pathways” by which information flows through the basal ganglia converge at the level of individual neurons in the subthalamic nucleus. © 1995 Wiley‐Liss, Inc.
Embryonic development of gonadotropin‐releasing hormone neurons in the sockeye salmon
Authors: Parhar Ishwar S. , Iwata Munehico , Pfaff Donald W. , Schwanzel‐Fukuda Marlene 
Published: January 2005

AbstractImmunocytochemistry and in situ hybridization were used to test the hypothesis that gonadotropin‐releasing hormone (GnRH) neurons are formed in the olfactory placode during embryonic development in a salmonid, Oncorhynchus nerka. The development of GnRH neurons and the pituitary cell types was examined from 19 through 910 days after fertilization. Immunoreactive GnRH was first detected at 19 days in the cells of the olfactory placode. GnRH immunoreactivity was not detected in any other structure of the central nervous system at this age. By day 24, GnRH‐immunoreactive neurons were seen in the apical, intermediate, and basal layers of the olfactory placode. From days 30 through 51, GnRH neurons were seen emerging from the epithelium, along the olfactory nerve, and at the rostral olfactory bulb. By day 41, GnRH immunoreactivity was lost in the nasal epithelium. In the 72–day‐old fish, most of the GnRH neuronal population was found in ganglia of the nervus terminalis, at the cribriform bone (gCB), and at the rostral olfactory bulb (gROB).On day 293, a decrease in GnRH‐immunoreactive neurons in the gCB and gROB was concomitant with an initial appearance of GnRH‐immunoreactive neurons and fibers along the caudoventral olfactory bulb. By day 462, the distribution of GnRH neurons and fibers was almost similar to adults. In maturing adults (910 days), GnRH‐immunoreactive neurons were rarely seen in the nasal regions, but were primarily found in the basal forebrain. GnRH fibers were widespread in the brain, proximal pars distalis, and in the pars intermedia of the pituitary.Our study supports the notion that neurons expressing salmon‐GnRH mRNA and peptide originate in the medial olfactory placode and migrate into the basal forebrain during development. The midbrain neurons did not express salmon‐GnRH mRNA or peptide in the larval and juvenile fish. © Wiley‐Liss, Inc.
Permanent neuronal cell loss in the cerebellum of rats exposed to continuous low blood alcohol levels during the brain growth spurt: A stereological investigation
Authors: Napper Ruth M. A. , West James R. 
Published: January 2005

AbstractThis study demonstrates that exposure to an alcohol regimen that resulted in low, uniform blood alcohol concentrations during a period of rapid brain growth can lead to a permanent deficit in the number of Purkinje cells and granule cells in the floccular‐parafloccular region of the cerebellum. Sprague‐Dawley rat pups were artificially reared and were administered alcohol over postnatal days 4 through 9, a period of brain development similar to that of the human third trimester. Two groups received a daily alcohol dose of 4.5 g/kg, administered either as a 10.2% solution in two of the 12 daily feedings (10.2% group) or as a 5.1% solution in four of the 12 feedings (5.1% group). A third group received a daily dose of 6.6 g/kg administered as a 2.5% solution in every feeding (2.5% group). The condensed patterns of alcohol administration resulted in high peak blood alcohol concentrations with near total clearance while the higher daily dose (6.6 g/kg), administered continuously, resulted in low but continuous blood alcohol concentrations. Pups were allowed to grow to adulthood and killed on postnatal day 115. The total number of Purkinje cells and granule cells in the floccular‐parafioccular region of the cerebellum was estimated using unbiased stereological methods. Exposure to alcohol resulted in significant deficits in the number of both Purkinje cells and granule cells at 115 days of age in all three treatment groups. Most importantly a significant deficit of Purkinje cells and granule cells was found following continuous exposure to low blood alcohol concentrations, i.e., in the 2.5% group. The total number of Purkinje cells in the 2.5% group was 2.33 ± 0.31 x 104 compared with 3.18 ± 0.30 x 104 in the artificially reared controls. The total number of granule cells in the 2.5% group and the controls was 1.24 ± 0.10 x 107 and 1.64 ± 0.19 x 107 respectively.These results support the hypothesis that exposure to a continuous, low blood alcohol concentration can result in the death of developing neurons and lead to permanent neuronal deficits. The degree of neuronal loss does not correlate with the magnitude of the peaks of blood alcohol concentration © Wiley‐Liss, Inc.
Morphology of higher‐order ocellar interneurons in the cockroach brain
Authors: Mizunami Makoto 
Published: January 2005

AbstractMost species of insects have two or three ocelli, in addition to a pair of compound eyes. In the cockroach ocellus, a large number of photoreceptors converge upon four second‐order neurons, which exit the ocellus and project into the ocellar tract neuropil of the brain, where they form synapses with at least 15 third‐order neurons. Third‐order neurons project into a variety of neuropils in the brain, including the posterior slope, a premotor center from which descending neurons originate. I examined the morphology and ocellar response of neurons in the posterior slope of the cockroach, using intracellular recording and stainings. Most ocellar neurons of the posterior slope exhibited transient depolarizations at the cessation of ocellar illumination, which seem to reflect sign‐conserving synaptic input from third‐order neurons. Ocellar neurons of the posterior slope project into various areas of the brain, including (1) the central complex, a higher center implicated in higher locomotory control, (2) the pedunculus of the mushroom body, an associative center, (3) the lamina (the first neuropil of the optic lobe), (4) the antennal lobe (olfactory center), (5) the tritocerebrum (mechanosensory center), and (6) the subesophageal and thoracic motor centers. These results suggest that the posterior slope is a high‐order ocellar center from which ocellar signals are transmitted to various target neuropils of the brain, as well as a premotor center to form descending motor commands. © 1995 Wiley‐Liss Inc.
Immunocytochemical mapping of serotonin and neuropeptides in the accessory medulla of the locust, Schistocerca gregaria
Authors: Würden Stefan , Homberg Uwe 
Published: January 2005

AbstractAccumulating evidence suggests that pigment‐dispersing hormone‐immunoreactive neurons with ramifications in the accessory medulla of the insect brain are involved in circadian pacemaking functions. We have used immunocytochemical techniques to investigate the neurochemical organization of the accessory medulla in the locust Schistocerca gregaria. Local neurons with arborizations largely restricted to the accessory medulla are immunoreactive with antisera against serotonin, Manduca sexta allatotropin, and Diploptera punctata allatostatin 7. Projection neurons with arborizations in the accessory medulla and fibers to the lamina and/or several areas in the midbrain including the posterior optic tubercles, the inferior and the superior protocerebrum show Phe‐Met‐Arg‐Phe (FMRF) amide‐, gastrin/cholecystokinin‐, crustacean cardioactive peptide‐, and substance P immunoreactivities. A unique neuron with tangential ramifications in the medulla and lamina and varicose terminals in the accessory medulla contains a peptide related to locustatachykinin I/II. Double‐label experiments show colocalization of pigment‐dispersing hormone‐immunoreactivity with substances related to gastrin/cholecystokinin, FMRFamide, substance P, or crustacean cardioactive peptide in certain projection neurons of the accessory medulla. The results suggest that neuropeptides and biogenic amines play major neuroactive roles in the accessory medulla of the locust. The abundance and extensive colocalization of neuropeptides in the locust accessory medulla is discussed with respect to the possible involvement of this brain area in circadian pacemaking functions. © 1995 Wiley‐Liss Inc.
Heterogeneity of astrocytes in human optic nerve head
Authors: Ye Hongqing , Hernandez M. Rosario 
Published: January 2005

AbstractPrevious studies demonstrated regional differences in the synthesis of extracellular matrix by astrocytes during optic nerve head (ONH) maturation and in glaucomatous optic neuro pathy, suggesting heterogeneity of astrocytes. To characterize different types of glial cells in human fetal and adult ONH, we used a variety of neural cell markers such as HNK‐1/N‐CAM, A2B5, galactocerebroside (GalC), myelin basic protein (MBP), and glial fibrillary acidic protein (GFAP). Cryostat or paraffin sections were prepared from fetal (16–25 weeks) and mature (8 months to 75 years old) ONH and processed for standard single/double immunocytochemistry. Two subpopulations of type 1 astrocytes were present in the mature prelaminar and laminar regions. Glial celia expressing only GFAP were identified as type 1A astrocytes at the edges of the cribriform plates. Cells forming the glial columns and lining the cribriform plates expressed both GFAP and fINK‐1/N‐CAM and were identified as type lB astrocytes. In the myelinated nerve, type 1A astrocytes form the glial limiting membrane. Cells labeled with GFAP and A2B5 were identified as type 2 astrocytes, and GFAP‐negative cells labeled with GaIC, MBP, and HNK‐1/N‐CAM were identified as oligodendrocytes. In fetal ONH, all glial cells expressed HNK‐1/N‐CAM. In older fetal ONH, some glial cells also expressed GFAP. No type 2 astrocytes or oligodendrocytes were present in the fetal ONH. In conclusion, at least two subpopulations of type 1 astrocytes exist in human ONH: Type 1A astrocytes may serve as structural support for a type lB astrocytes, which retain the developmental neural marker HNK‐1/N‐CAM, may have a more complex function by interfacing between blood vessels and other connective tissue surfaces. These findings demonstrate the heterogeneity of astrocytes in the human ONH and suggest differential regional responses to changes in their microenvironment. © 1995 Wiley‐Liss Inc.
Neuropeptide changes following excitotoxic lesion of the insular cortex in rats
Authors: Cheung R. T. F. , Cechetto D. F. 
Published: January 2005

AbstractFollowing middle cerebral artery occlusion in Wistar rats, the immunoreactivity of neuropeptide Y increased ipsilaterally in the insular cortex and basolateral nucleus of the amygdala. In addition, the immunoreactivity of leucine‐enkephalin, dynorphin, and neurotensin increased in the ipsilateral central nucleus of the amygdala. The amygdalar neurochemical changes are likely the result of damage to the insular cortex, although other cortical areas were also affected by the ischemia. To investigate whether damage to the insular cortex is essential in eliciting these changes, a localized lesion of the right or left insular cortex was produced by microinjection of D,L‐homocysteic acid. Control animals received injections of vehicle into the right or left insular cortex or D,L‐homocysteic acid into the right primary somatosensory cortex. Neurochemical changes were examined immunohistochemically with the peroxidase antiperoxidase reaction 5 lays after the injection. The immunoreactivity of neuropeptide Y increased locally after excitotoxic damage to the insular cortex or primary somatosenaory cortex. The amygdalar neurochemical changes, including neuropeptide Y increase in the basolateral nucleus and leucine‐enkephalin, dynorphin, and neurotensin increase in the central nucleus, were seen only when the ipsilateral insular cortex was lesioned. These neurochemical changes were similar to those seen 5 days after middle cerebral artery occlusion.Our findings indicat that damage to the insular cortex is essential in eliciting the neurochemical changes in the ipsilateral amygdala. In addition, the change in neuropeptide Y in the cortex appears to be a local reaction occurring irrespective of location of the lesion and glutamate receptor activation may be involved. © 1995 Wiley‐Liss Inc.
Projection of individual axons from the pretectum to the dorsal lateral geniculate complex in the cat
Authors: Uhlrich Daniel J. , Manning Karen A. 
Published: January 2005

AbstractThe dorsal lateral geniculate nucleus of the thalamus transmits visual signals from the retina to the cortex. Within the lateral geniculate nucleus, the ascending visual signals are modified by the actions of a number of afferent pathways. One such projection originates in the pretectum and appears to be active in association with oculomotor activity. Much remains unknown about the pretectal‐geniculate projection. Our purpose was to examine for the first time individual axon arbors from the pretectum that project to the lateral gesticulate nucleus, describing their topography and nuclear and laminar targets.We made injections of the anterograde tracer Phaseolus vulgaris leucoagglutinin into the cat pretectum, targeting the nucleus of the optic tract. Serial 40 μm coronal sections were processed by using immunohistochemiatry to reveal labeled axons that were then serially reconstructed using light microscopy. Pretectal‐geniculate axons appeared morphologically heterogeneous in terms of swelling size, branching patterns, and laminar target. Most axons innervated the geniculate A laminae. A separate, smaller population innervated the C laminae. All axons exhibited substantially greater spread medial‐laterally than rostral‐caudally in the lateral gesticulate nucleus, displaying a topographical organization for visual field elevation, but not azimuth. Many pretectal axons that projected to the LGN also innervated adjacent structures, including the medial interlaminar nucleus, the perigeniculate nucleus, and/or the pulvinar. These results indicate that the projection from the pretectum to the dorsal lateral geniculate nucleus is heterogeneous, is semitopographical, and may coordinate neural activity in the lateral geniculate nucleus and in neighboring visual thalamic structures in association with oculomotor events. © 1995 Wiley‐Liss, Inc.
GABAergic neurons in the rat pontomesencephalic tegmentum: Codistribution with cholinergic and other tegmental neurons projecting to the posterior lateral hypothalamus
Authors: Ford Blair , Holmes Colin J. , Mainville Lynda , Jones Barbara E. 
Published: January 2005

AbstractThe present study was undertaken to determine the frequency and distribution of GABAergic neurons within the rat pontomesencephalic tegmentum and the relationship of GABAergic cells to cholinergic and other tegmental neurons projecting to the hypothalamus. In sections immunostained for glutamic acid decarboxylase (GAD), large numbers of small GAD‐positive neurons (∼50,000 cells) were distributed through the tegmentum and associated with a high density of GAD‐positive varicosities surrounding both GAD‐positive and GAD‐negative cells. Through the reticular formation, ventral tegmentum, raphe nuclei, and dorsal tegineritum, GAD‐positive cells were codistributed with larger cells, which included neurons immunostained on adjacent sections for glutamate, tyrosine hydroxylase (TH), serotonin, or choline acetyltransferase (ChAT). In sections dual‐immunostained for GAD and ChAT, GABAergic neurons were seen to be intermingled with less numerous cholinergic cells (∼2,600 GAD+ to ∼ 1,400 ChAT+ cells in the laterodorsal tegmental nucleus, LDTg).Retrograde transport of cholera toxin (CT) was examined from the posterior lateral hypothalamus, where a major population of cortically projecting neurons are located. A small number of GABAergic cells were retrogradely labeled, representing a small percentage of all the GABAergic neurons (∼1%) and of all the hypothalamically projecting neurons (∼6%) in the tegmentum. The double‐labeled GAD+/CT+ cells were commonly found ipsilaterally within (1) the deep mesencephalic reticular field, codistributed with putative glutamatergic projection neurons; (2) the ventral tegmental area, substantia nigra coinpacta, and retrorubral field, codistributed with dopaminergic projection neurons; (3) dorsal raphe, codistributed with serotonergic projection neurons; and (4) laterodorsal and pedunculopontine tegmental nuclei, codistributed with and in similar proportion to cholinergic projection cells (20–30% in LDTg). Acting as both projection and local neurons, the pontomesencephalic GABAergic cells would have the capacity to modulate the influence of the “ascending reticular activating system” and its chemically specific constituents upon cortical activation. © 1995 Wiley‐Liss, Inc.