bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunohistochemistry of aromatic L‐amino acid decarboxylase in the cat forebrain
Authors: Kitahama Kunio , Denoyer Michel , Raynaud Brigitte , Borri‐Voltattorni Carla , Weber Michel , Jouvet Michel 
Published: January 2005

AbstractThe topographic distribution of aromatic L‐amino acid decarboxylase (AADC)‐immunoreactive (IR) neurons was investigated in the cat hypothalamus, limbic areas, and thalamus by using specific antiserum raised against porcine kidney AADC. The perikarya and main axons were mapped on an atlas in ten cross‐sectional drawings from A8 to A16 of the Horsley Clarke stereotaxic plane. AADC‐IR neurons were widely distributed in the anterior brain. They were identified in the posterior hypothalamic area, rostral arcuate nucleus of the hypothalamus, dorsal hypothalamic area, and periventricular complex of the hypothalamus, which contain tyrosine hydroxylase (TH)‐IR cells and are known as All to A14 dopaminergic cell groups. AADC‐IR perikarya were also found in the other hypothalamic areas where few or no TH‐IR cells have been reported: the supramamillary nucleus, tuberomamillary nucleus, pre‐ and anterior mamillary nuclei, caudal arcuate nucleus, dorsal hypothalamic area immediately ventral to the mamil‐lothalamic tract, anterior hypothalamic area, area of the tuber cinereum, retrochiasmatic area, preoptic area, suprachiasmatic and dorsal chiasmatic nuclei. We also identified them in the anterior commissure nucleus, bed nucleus of the stria terminalis, stria terminalis, medial and central amygdaloid nuclei, lateral septal nucleus, and nucleus of the diagonal band of Broca. AADC‐IR neurons were localized in the ventromedial part of the thalamus, lateral posterior complex, paracentral nucleus and lateral dorsal nucleus of the thalamus, medial habenula, parafascicular nucleus, subparafascicular nucleus, and periaqueductal gray. Conversely, we detected only a few AADC‐IR cells in the supraoptic nucleus whose rostral portion contains TH‐IR perikarya. Comments are made on the relative Idealizations of the AADCvIR and THvIR neurons, on species differences between the cat and rat, as well as on the possible physiological functions of the enzyme AADC.
Ultrastructural characterization of substance P‐like immunoreactive neurons in the rostral ventrolateral medulla in relation to neurons containing catecholamine‐synthesizing enzymes
Authors: Milner Teresa A. , Pickel Virginia M. , Abate Cory , Joh Tong H. , Reis Donald J. 
Published: January 2005

AbstractSubstance P (SP) and catecholamines, particularly adrenaline, have been implicated in cardiovascular responses mediated by neurons in the rostral ventrolateral medulla (RVL). Immunoperoxidase labeling of an antiserum against SP and/or immunoautoradiographic localization of catecholamine (tyrosine hydroxylase—TH)‐ or adrenaline (phenylethanolamine N‐methyltransferase—PNMT)‐synthesizing enzymes were examined histologically to determine the cellular basis for a functional interaction involving either synaptic or intracellular relations between these putative transmitters in the adult rat RVL. Peroxidase labeling for SP was localized in perikarya, dendrites, and axon terminals. Most of these perikarya were located medial and ventral to those labeled with TH or PNMT within the same section. However, as others have previously demonstrated by light microscopy, colocalization of SP‐like immunoreactivity (SPLI) and PNMT was seen in a few perikarya of colchicine treated animals. Both single‐ and dual‐labeled perikarya contained abundant dense core vesicles.The terminals with SPLI were 0.4–1.4 μm in diameter and contained a few mitochondria, a large population of small, clear vesicles, and from three to 11 large dense core vesicles. In some cases the terminals were seen in continuity with more proximal processes of neurons in the RVL. These terminals formed synapses with a few perikarya and many dendrites, some of which also contained SPLI. In the material dually labeled for TH and SP, terminals with SPLI (n = 32) formed synaptic junctions primarily with TH‐labeled dendrites (69%); the remainder were with TH‐labeledperikarya (6%) or with unlabeled dendrites (25%). The axosomatic junctions were exclusively symmetric, whereas the majority of axodendritic junctions were primarily asymmetric on small dendrites (0.8–1.0 μm in diameter) or dendritic spines. In sections dually labeled for PNMT and SP, the terminals containing SPLI (n = 37) formed synaptic associations with PNMT‐labeled perikarya (11%), PNMT‐immunoreactive dendrites (59%), or with perikarya and dendrites lacking PNMT immunoreactivity (30%). The axosomatic junctions were all symmetric and most often associated with the spinous portion of the soma. The axodendritic junctions were primarily asymmetric and were found both on the shaft and spinous portion of the PNMT‐labeled dendrites. In addition, both TH‐ and PNMT‐labeled somata and dendrites received symmetric and asymmetric contacts from terminals lacking SPLI.These findings provide ultrastructural evidence that in the rat RVL, SP or a closely related neurokinin located in intrinsic neurons or other afferents provides a major direct input to adrenergic neurons. Additionally, the peptide may modulate the activity of adrenergic neurons through synapses with neurons containing SP or other transmitters or through intracellular interactions.
In situ hybridization analysis of osmotic stimulus‐induced changes in ribosomal RNA in rat supraoptic nucleus
Authors: Kawata M. , McCabe J. T. , Harrington C. , Chikaraishi D. , Pfaff D. W. 
Published: January 2005

AbstractA quantitative in situ hybridization analysis was used to investigate changes in levels of ribosomal RNA (rRNA) in neurons of the supraoptic nucleus (SON) of rats stimulated osmotically by giving 2% NaCl as drinking solution for 0 (control rats), 1, 4, and 14 days. The quantitation was autoradiographically accomplished by in situ hybridization with a nick‐translated tritiated ribosomal DNA probe and with the use of computer‐based image analysis system. The mean number of grains per neuron in the ventral SON was significantly increased: 1.8‐fold for 1 day, 2.9‐fold for 4 days, and 1.7‐fold for 14 days of salt loading, whereas the mean number of grains per neuron in the dorsal SON was increased 1, 3‐fold for 1 day, 2.5‐fold for 4 days, and 1.7‐fold for 14 days. Kolmogorov‐Smirnov analysis of frequency histograms of grains per neuron indicated that the amount of rRNA in neurons in the ventral and dorsal SON was significantly increased by osmotic stimulation. These increases were accompanied by increases in cell size. The subcellular location of hybridizable rRNA in magnocellular neurons was altered by osmotic stimulation. Following 1–14 days of salt‐drinking, rRNAs appeared to be more unevenly distributed throughout the cytoplasm. These findings are consistent with the notion that hyperosmotic stimulation has a substantial effect on the expression of rRNA genes in neurons of both the ventral and dorsal SON.
Quantitative relationships between motoneuron and muscle development in Xenopus laevis: Implications for motoneuron cell death and motor unit formation
Authors: McLennan Ian S. 
Published: January 2005

AbstractA common approach to the study of neural regression has been to correlate the timing of cell loss with other events such as target development. Most of these studies have areas of uncertainty. First, the analysis is normally carried out on groups of neurons that innervate a variety of targets. Second, there are some doubts about the reliability of light microscopic quantitation of muscle development. In this study, the period of cell death in the semimembranosus motor pool of Xenopus laevis has been estimated and correlated with an electron microscopic study of the development of the semimembranosus.The period of cell death of semimembranosus motoneurons was estimated on the basis of their position in the spinal cord and from the number of myelinated axons in the semimembranosus motor nerve. The semimembranosus motor pool contained approximately 70 motoneurons and was located 17–37% along the rostrocaudal axis of the lumbar cord. Cell loss from this motor pool occurred between stages 53–54 and 56, whereas cell death in the entire lumbar cord extended beyond stage 58. Primary myogenesis occurred between stages 53 and 54 in the semimembranosus. There was then a hiatus in myotube production until secondary myogenesis began around stage 56.It is concluded that secondary myotubes are not involved in regulating motoneuron cell death and that the number of primary myotube clusters is similar in magnitude to the number of motoneurons that will ultimately survive the period of cell death. The implications of these observations for theories of cell death and motor unit formation are discussed.
Capsaicin‐induced neuronal degeneration: Silver impregnation of cell bodies, axons, and terminals in the central nervous system of the adult rat
Authors: Ritter Sue , Dinh Thu T. 
Published: January 2005

AbstractCapsaicin is a neurotoxic substance valued in neurobiological research because of its ability to selectively damage small unmyelinated primary sensory neurons. Previous work has indicated that systemic capsaicin administration causes permanent neuronal degeneration in neonatal rats, but evidence that capsaicin has a similar effect in adults is equivocal and incomplete. Therefore, we used silver impregnation, a method that labels degenerating neurons, to examine the central nervous system of adult rats after systemic capsaicin treatment. Adult rats were injected with a single intraperitoneal dose of capsaicin (50 or 90 mg/kg) or vehicle solution and killed 6, 12, 18, 24, 48, 96, or 240 hours later. Sections of brain and spinal cord were stained with the Carlsen–de Olmos cupric silver method. As reported previously, stained sections revealed degeneration in areas known to be innervated by small‐diameter primary sensory fibers: the substantia gelatinosa of the spinal cord dorsal horn and spinal trigeminal nucleus, the solitary nucleus and tract, and the lateral borders of the area postrema. In addition, axon and terminal degeneration was observed in several discrete forebrain and hindbrain areas not previously associated with capsaicin‐induced degeneration in either adult or neonatal rats: the inferior olive, the olivary pretectal nucleus, the interpeduncular nucleus, the suprachiasmatic nucleus, and the lateral septum/medial accumbens region. Furthermore, degenerating cell bodies were observed in the intrafascicular nucleus of the ventromedial midbrain tegmentum, in the supramammillary nucleus, and in the posterior hypothalamic area. Unilateral nodose ganglionectomy produced terminal staining on the denervated side very similar to that induced bilaterally by capsaicin. In addition, unilateral nodose ganglionectomy 1 month prior to capsaicin injection greatly attenuated staining in the ipsilateral nucleus of the solitary tract, confirming the hypothesis that capsaicin damages vagal sensory neurons innervating this nucleus. Capsaicin‐induced damage in adult rats was long‐lasting, since the second of two capsaicin treatments spaced 4.5 months apart produced no additional degeneration.
Induction of aberrant functional afferents to the chick cochlear nucleus
Authors: Jackson Hunter , Parks Thomas N. 
Published: January 2005

AbstractSurgical extirpation of the otocyst on embryonic day (E) 3 in chick embryos prevents formation of the cochlear nerve and results in development of an aberrant axonal projection from the contralateral cochlear nucleus (nucleus magnocellularis, NM) to the deafferented NM. We have studied the morphology of this projection using horseradish peroxidase injections in NM axons and light and electron microscopy. The ability of the projection to activate its target neurons synaptically was assessed by means of extracellular microelectrode recording from in vitro preparations of the chick brainstem. The aberrant projection arises as a vertically directed branch from the contralaterally traveling NM axon at the medial border of nucleus laminaris (NL). This axonal branch forms boutonal endings that may terminate anywhere in NM but are most common in its ventral and medial regions. In our experiments, this projection is not seen on the unoperated side of experimental animals or in normal controls from E11 onward but is found on the operated sides of all experimental animals, including those with bilateral removal of the otocysts. The aberrant projection persists at least from E11 through hatching and has essentially identical features in unilaterally and bilaterally lesioned animals. The endings of the aberrant projection are boutonal in form and, in the electron microscope, exhibit all of the elements associated with normal synapses. Electrophysiological studies confirm that stimulation of the aberrant axons can elicit postsynaptic responses in NM and suggest that these synapses use an excitatory amino acid neurotransmitter.
A comparison of the efferents of the amygdala and the hippocampal formation in the rhesus monkey: I. Convergence in the entorhinal, prorhinal, and perirhinal cortices
Authors: Saunders Richard C. , Rosene Douglas L. 
Published: January 2005

AbstractThis is the first in a series of papers investigating the neuroanatomical basis for the interaction of the amygdala and the hippocampal formation in the rhesus monkey. The present report focuses on the complementary and convergent projections of the amygdala and hippocampal formation to the entorhinal and perirhinal cortices. These results were obtained from complementary experiments using injections of radioactively labeled amino acids to identify the anterograde projection patterns and injections of horseradish peroxidase and fluorescent retrograde tracers to confirm the cytoarchitectonic location of the neurons of origin for each projection.The results of this investigation demonstrate that both the hippocampal formation and the amygdala project to the entorhinal and perirhinal cortices where, with a few exceptions, the major projections of each structure generally are found in different layers of the same cytoarchitecture subdivisions of the entorhinal cortex but overlap in the same layers of the perirhinal cortex. Thus, the lateral and accessory basal nuclei of the amygdala project to layer 3 of areas Pr1, 28I, 28L, and 28S, and the accessory basal nucleus projects strongly to layer 1 of these same areas. In contrast, the subiculum, prosubiculum, and subfield CA1 of the of the hippocampal formation all have a projection to layer 5 of these same areas. In area 28M, the accessory basal nucleus of the amygdala projects to layer 1, while the subiculum, prosubiculum, and subfield CA1 of the hippocampal formation all project to layer 5, and the presubiculum projects to layer 3.In addition to these complementary laminar projectios, there are a few areas of laminar overlap. Thus in area 28S, both the presubiculum and the CA1 subfield project to layer 3, where the lateral and accessory basal amygdaloid nuclei also project. Similarly, in 28I there is a major projection from the presubiculum and a lighter projection from the subiculum and CA1 to layer 3, where the lateral and accessory basal nuclei also project. There is also extensive laminar overlap in the perirhinal cortex. From the amygdala, the accessory basal nucleus projects to layers 1 and 3 and the lateral basal nucleus to layers 3, 5, and 6, while from the hippocampal formation, the prosubiculum projects to layers 3, 5, and 6, and the CA1 subfield projects to layer 5. This pattern of hippocampal and amygdaloid projections to the entorhinal and perirhinal cortices indicates that these cortices constitute a region of potentially extensive interaction between the amygdala and the hippocampus.
Comparison of the efferents of the amygdala and the hippocampal formation in the rhesus monkey: II. Reciprocal and non‐reciprocal connections
Authors: Saunders Richard C. , Rosene Douglas L. , Van Hoesen Gary W. 
Published: January 2005

AbstractThe pattern of direct connections between the amygdala and the hippocampal formation in the rhesus monkey (Macaca mulatta) was delineated by using both anterograde and retrograde tract‐tracing techniques.From the amygdala the accessory basal, medial basal, and the cortical nuclei and the cortical amygdaloid transition area send projections to the hippocampal formation. The efferents from the magnocellular part of the accessory basal nucleus and the cortical nuclei terminate in the molecular layer of subfields CA3, CA2, and CA1′, and to a lesser extent in the molecular layer and the superficial part of the pyramidal cell layers of the prosubiculum. In contrast, the projections from the medial basal nucleus and the cortical amygdaloid transition area terminate in the molecular layer and the superficial part of the pyramidal cell layers of the prosubiculum only.From the hippocampal formation, subfield CA1′ and the prosubiculum send efferents that terminate in the medial basal nucleus, the cortical transition area, and the ventral part of the cortical nuclei. In addition, the CA1′ subfield projects to the ventral, parvicellular part of the accessory basal nucleus.The present data emphasize an important role for the prosubiculum and the CA1′ subfield in medial temporal lobe area connections. Both regions, in addition to supporting direct connections between the amygdala and the hippocampal formation, also have extensive connections with the entorhinal cortex. As for the amygdala, the accessory basal nucleus sends efferents to both the hippocampal formation and the entorhinal cortex. The data demonstrate an anatomical means by which the amygdala, hippocampal formation, and the entorhinal cortex may interact. It is proposed that these connections may be important in the limbic memory system.
Analysis of the rat interpeduncular subnuclei by immunocytochemical double‐staining for enkephalin and substance P, with some reference to the coexistence of both peptides
Authors: Shinoda Koh , Michigami Toshimi , Awano Kikuo , Shiotani Yahe 
Published: January 2005

AbstractThe rat interpeduncular nucleus (IPN) was immunocytochemically double‐stained for enkephalin (ENK) and substance P (SP) on the same sections. On the basis of both peptidergic distribution patterns and topographic relationship, the IPN was divided into nine subnuclei and one cap: the rostral subnucleus (IP‐R), the central subnucleus (IP‐C), the rostral‐lateral subnucleus (IP‐RL), the main lateral subnucleus (IP‐L), the caudal‐lateral subnucleus (IP‐CL), the dorsal‐lateral subnucleus (IP‐DL), the dorsal‐medial subnucleus (IP‐DM), the apical subnucleus (IP‐A), the intermediate subnucleus (IP‐I), and the dorsal cap (IP‐Cap). As the descriptions of the IP‐RL, IP‐L, and IP‐CL were inconsistent with previous reports, they were reevaluated; the IP‐RL was proposed as the region situated in the lateral portion at rostral levels and characterized by the lack of ENK and SP immunoreactive structures, the IP‐L as the region situated throughout the rostrocaudal extent in the lateral portion of the IPN and containing the highest density of SP immunoreactive fibers but no ENK immunoreactive fibers, and the IP‐CL as the region situated just laterocaudal to the IP‐L in the caudal pole of the IPN and containing ENK immunoreactive cells and fibers but no SP immunoreactive structures.Our results also showed that some cells in the IP‐R have both ENK and SP immunoreactivity. This coexistence was observed in some small spherical cells of the IP‐R, but rarely in larger oval‐shaped cells, which occasionally showed only ENK immunoreactivity. In addition, paired ENK immunoreactive fiber bundles entering the IP‐R were found to run just rostral to the paired SP immunoreactive columns, both of which composed parts of the interpedunculotegmental tract.A three‐dimensional model representing the subnuclear organization of the IPN was proposed on the basis of the present results.
Anatomical specificity of noradrenergic inputs to the paraventricular and supraoptic nuclei of the rat hypothalamus
Authors: Cunningham E. T. , Sawchenko P. E. 
Published: January 2005

AbstractThe distribution of neural inputs to the paraventricular (PVH) and supraoptic (SO) nuclei from the regions of the A1, the A2, and the A6 (locus coeruleus) noradrenergic cell groups was investigated by using a plant lectin, Phaseolus vulgaris leucoagglutinin (PHA‐L), as an anterogradely transported tracer. An immunofluorescence double‐labeling procedure was used to determine the extent to which individual anterogradely labeled fibers and terminals in the PVH and the SO also displayed immunoreactive dopamine‐β‐hydroxylase (DBH), a marker for catecholaminergic neurons. The results may be summarized as follows: (1) Projections from the A1 region were found primarily, and in some experiments almost exclusively, in those parts of the magnocellular division of the PVH and the SO known to contain vasopressinergic neurons. (2) Projections from the A2 region were distributed primarily throughout the parvicellular division of the PVH and were most dense in the dorsal medial part, a region known to contain a prominent population of corticotropin‐releasing factor (CRF)‐immunoreactive neurons. In addition, a less‐dense projection to the magnocellular division of the PVH and to the SO was consistently found. (3) Fibers originating from the locus coeruleus were distributed almost exclusively to the parvicellular division of the PVH, with the most prominent input localized to the periventricular zone, a part of the PVH known to contain dopamine‐, somatostatin‐, and thyrotropin‐releasing‐hormone‐containing neurons. We found no evidence for a projection from A6 to the SO. (4) The majority of fibers originating from the A1, the A2 or the A6 regions contained DBH immunoreactivity, although an appreciable number did not. These results suggest that each of the three brainstem noradrenergic cell groups that contribute to the innervation of the PVH and/or the SO is in a position to modulate the activity of anatomically and chemically distinct groups of neurosecretory neurons.
Cell birthdays and rate of differentiation of ganglion and horizontal cells of the developing cat's retina
Authors: Zimmerman Roger P. , Polley Edward H. , Fortney Richard L. 
Published: January 2005

AbstractTritiated thymidine autoradiography experiments demonstrated that three cell classes are produced by ventricular cells during the first phase of neurogenesis: retinal ganglion cells, A‐type horizontal cells, and cone photoreceptors. Light microscopy and scanning electron microscopy were used to study the migration and morphological differentiation of these three cell classes.The patterns of postmitotic migration are of interest because these three classes of cells are found in three different layers of the adult retina. Cones retain their position at the outer limiting membrane (OLM) throughout life and do not migrate. Ganglion cells migrate immediately to the proximal (vitread) layer of the retina and begin to differentiate. In contrast, A‐type horizontal cells migrated away from the OLM within 10–14 days after their final mitosis but were morphologically relatively undifferentiated at that time. Subsequent differentiation of the A‐type horizontal cell is also protracted; dendrites are not observed until approximately 3 weeks after the final mitosis.These observations suggest that there are several interacting mechanisms involved in neurogenesis: a sequence that produces a specific cohort of committed cells at a specific time, the subsequent migration of postmitotic neuroblasts to an appropriate position in the retina, and a spatial gradient of differentiation increasing from distal to proximal layers. While this distribution of differentiated cells early in fetal development is striking, the existence of underlying time‐dependent processes that might cause this apparent spatial phenomenon cannot be eliminated.