bluuebunny/crossref_metadata_2025_split huggingface dataset:
Times of origin of brachial sensory neurons are not correlated with neuronal phenotype
Authors: Mendelson Bruce , Frank Eric 
Published: January 2005

AbstractThe times of origin (birthdays) of sensory and motor neurons that innervate the triceps brachii muscles of the bullfrog (Rana catesbeiana) were determined to learn whether neurons innervating a specific target are generated at a particular developmental time. 3H‐thymidine (3H‐TdR) was made available continuously throughout a specific developmental period. All neurons that innervated the triceps muscle in juvenile frogs (identified by filling cells retrogradely with HRP) were generated prior to metamorphosis. Triceps motoneurons were all postmitotic by early limb bud stage V. Triceps sensory neurons were generated over a protracted period of larval development, from stage V through early pre‐metamorphic stage XV. Most large triceps sensory neurons were generated before the majority of the small cells. However, there was considerable overlap in the times of origin of the two populations; both large and small cells were generated at all stages of sensory neurogenesis. There was thus no strict relationship between sensory soma size and birthdate. Late‐generated sensory neurons tended to be located in clusters within ganglia, whereas HRP‐filled triceps neurons were not. These 3H‐labeled clusters may represent clones of neurons which would indicate that late stage neuroblasts give rise to neurons that supply different peripheral targets. The time course of triceps neuronal generation paralleled that of all other brachial sensory neurons implying that the time of last cell division does not in itself determine either the target a neuron will innervate or the sensory modality to which it will respond.
Intracellular labeling of neurons in the medial accessory olive of the cat: II Ultrastructure of dendritic spines and their gabaergic innervation
Authors: De Zeeuw C. L. , Ruigrok T. J. H. , Holstege J. C. , Jansen H. G. , Voogd J. 
Published: January 2005

AbstractIn order to describe the morphology of dendritic spines of identified neurons in the cat inferior olive together with their gamma‐aminobutyric acid (GABA) synaptic input, a technique was used combining intracellular labeling of horseradish peroxidase with postembedding gold‐immunocytochemistry. With this technique physiologically identified olivary cells were reconstructed with the light microscope, and the horseradish peroxidase reaction product and immunogold labeling were subsequently examined in serial sections at the ultrastructural level. In addition, a degenerating neuron was observed, resulting in a triple labeling in single ultrathin sections.Quantitative and three‐dimensional analysis showed that the dendritic spines were composed of long, thin stalks ending in one or more spine heads. The spines of cells located in the caudal half of the medial accessory olive (type I cells, characterized by dendrites which run away from the soma) were found to be less complex than those, of cells located rostrally in this olivary subnucleus (type II cells, characterized by dendrites which tend to turn back towards the soma). Most, if not all, of the spines of both cell types were located within glomeruli. On average, the spines within individual glomeruli originated from 6 different dendrites (with a maximum of 8). Different spines within the same glomerulus were never derived from different dendrites of the same olivary neuron, but single spines frequently gave rise to several spine heads, which could be located either within different glomeruli or inside a single glomerulus, The glomerular spine heads originating from the same spine were rarely located near one another. All spines and most of the spine heads were contacted by both GABAergic and non‐GABAergic terminals. Most of the GABAergic terminals contained pleomorphical vesicles and displayed symmetric, synapses whereas the non‐GABAergic terminals showed usually round to oval vesicles and asymmetric synapses.
Gonadotropin‐releasing hormone (GnRH) immunoreactive system in the brain of the dwarf gourami (Colisa lalia) as revealed by light microscopic immunocytochemistry using a monoclonal antibody to common amino acid sequence of GnRH
Authors: Oka Yoshitaka , Ichikawa Masumi 
Published: January 2005

AbstractThe present paper aims to give a morphological basis for the study of the terminal nerve system and its relation to the whole gonadotropin‐releasing hormone (GnRH) immunoreactive (ir) neuronal system. We examined the GnRH‐ir neuronal system of a tropical fish, the dwarf gourami, by using a recently developed monoclonal antibody against GnRH (LRH13) which recognizes the amino acid sequence common to all known variants of GnRH (Park and Wakabayashi, Endocrinol. Jpn. 33:257–272, '86). The ganglion cells of the terminal nerve (TN‐ggl cells) in the transitional area between the olfactory bulb and the telencephalon reacted strongly with the LRH13. A distinct bundle of axons emanating from the TN‐ggl cells ran caudally through the ventral telencephalon and the preoptic area. Some of these axons entered the optic nerve and innervated the retina. The remaining axons continued caudally to enter the hypothalamus and the midbrain. A second group of GnRH‐ir cell bodies was found in the preoptic area. A distinct bundle of GnRH‐ir fibers originating from these cell bodies innervated the pituitary. This pathway is equivalent to the preoptico‐infundibular pathway of other vertebrates, and the GnRH in this pathway is presumed to function as hypophysiotrophic hormone to facilitate the release of gonadotropins from the pituitary. The distribution of GnRH‐ir fibers in the brain was extensive. Most fibers apparently originated from the TN‐ggl cells and covered various brain regions from the olfactory bulb to the spinal cord. They were especially abundant in the olfactory bulb, ventral telencephalon, preoptic area, optic tectum, and some hypothalamic areas. Thus, GnRH might function as a neuromodulator and/or neurotransmitter in these areas. The abundant GnRH‐ir fibers in the ventral telencephalon and the preoptic area might affect some aspects of sexual behavior, since these areas have been suggested to be involved in the control of sexual behavior in teleosts.
Development of compartmentalized innervation of the rat gluteus maximus muscle
Authors: English Arthur W. M. 
Published: January 2005

AbstractThe innervation territories of the nerves to the gluteus maximus muscle were investigated in neonatal rats by using evoked electromyographic mapping techniques. Similar methods were employed to determine the terminal fields of individual motoneurons. Both at birth and after the period of neuromuscular synapse elimination, rat gluteus maximus is partitioned by its two muscle nerves. Each of these partitions is further divided into neuromuscular compartments by the primary branches of the muscle nerves. The terminal fields of individual motoneurons are about as well localized in early neonates as in 26 day‐old animals. Intracellular records from gluteal muscle cells reveal that some myotubes in a narrow region near the center of the muscle receive inputs from both of the muscle nerves during the period of polyneauronal innervation. Such cross‐compartmental innervation could be demonstrated only until the eighth postnatal day, even though polyneuronally innervated muscle cells were found as late as postnatal day 18. Analysis of the trajectories of individual axons filled with horseradish peroxidase indicates that they branch into only one primary branch of the nerves to gluteus maximus, both in newborn and 14 day‐old pups. The innervation of gluteus maximus at birth is essentially restricted to neuromuscular compartments. Synapse elimination probably plays a minor role in establishing neuromuscular compartments.
Selective labeling of sensory hair cells and neurons in auditory, vestibular, and lateral line systems by a monoclonal antibody
Authors: Kornblum Harley I. , Corwin Jeffrey T. , Trevarrow Bill 
Published: January 2005

AbstractThis study reports that zn‐1, a monoclonal antibody, labels hair cells but not supporting cells in the inner ear and the lateral line of the axolotl salamander, Ambystoma mexicanum. Zn‐1 immunocytochemically labels the cytoplasm and stereocilia of mature hair cells in the sacculus, in the utriculus, and in the mechanoreceptive neuromast organs of the lateral line. Lower levels of labeling mark newly formed hair cells in the periphery of the sacculus and in regenerating neuromasts. Zn‐1 also selectively labels neuronal processes and perikarya in the lateral line nerves and ganglia and the VIIIth cranial nerve and ganglion. Processes and perikarya are labeled by zn‐1 in the dorsolateral medulla oblongata, at sites of termination of the afferent octaval and lateral line neurons. Western blot analysis revealed that zn‐1 labels one or more proteins with molecular weights of 80 and 160 kDa. The identity of these protein bands remains to be determined. The presence of a specific epitope expressed in both hair cells and neurons, but not in supporting cells, in the vestibular and auditory epithelia of the ear and in the mechanoreceptive neuromasts of the lateral line suggests shared cytogenetic heritages. These findings are consistent with a close evolutionary relationship between otic and lateral line senses, such as that inherent to the theoretical evolutionary scheme outlined in van Bergeijk's “acousticolateralis hypothesis.” The protein recognized by zn‐1 is as yet unidentified, but its conservative evolution suggests that it may serve an important function in the statoacoustic and lateral line systems.
Rod bipolar cells in the mammalian retina show protein kinase C‐like immunoreactivity
Authors: Greferath Ursula , Grünert Ulrike , Wässle Heinz 
Published: January 2005

AbstractAn antibody directed against protein kinase C (PKC) was applied to various mammalian retinae. In the cat, rat, rabbit, and macaque monkey we found PKC‐like immunoreactivity in bipolar cells which had the morphology of rod bipolar cells; in the rat some amacrine cells were also immunoreactive. In the outer plexiform layer, labeled dendrites were always the central elements of the rod spherule invagination, and in the inner plexiform layer only rod bipolar axons and their axon terminals were immunoreactive. The antibody against PKC thus can be used to distinguish rod bipolar cells from cone bipolar cells.The antibody against PKC was used to determine the densities of rods and rod bipolar cells in the cat retina. In the central retina we found a rod to rod bipolar ratio of 16 to 1, in the periphery the ratio increases to 25 to 1.In freshly dissociated retina, cells with rod bipolar morphology could be identified; these cells were also labeled with the anti‐PKC antibody. Hence, PKC‐like immunoreactivity can be used to recognize rod bipolar cells in vitro.
Organization of serotonin 1A and 1B receptors in the nucleus of the solitary tract
Authors: Manaker Scott , Verderame Holly M. 
Published: January 2005

AbstractWe utilized 3H‐8‐hydroxy‐N,N‐dipropyl‐2‐aminotetralin (3H‐DPAT) and 125I‐iodocyanopindolol (125I‐CYP) to label serotonin (5HT) 1A and 5HT1B receptors, respectively, in sections of the rat brain after characterizing the pharmacologic specificity of these agents. We then used quantitative autoradiography to measure the concentrations of 5HT1A and 5HT1B receptors in individual subnuclei of the nucleus of the solitary tract (NTS) and adjacent structures of the dorsal vagal complex. The highest 5HT1A receptor concentrations were observed within the central and intermediate subnuclei of the NTS, with low quantities of 3H‐DPAT binding sites observed in the hypoglossal nucleus and dorsal motor nucleus of the vagus. In contrast, the density of 5HT1B receptors was relatively homogeneous through all NTS subnuclei, with the highest concentrations localized within the ventrolateral subnucleus. The hypoglossal and dorsal motor nuclei had slightly higher 5HT1B receptor densities than the NTS subnuclei, whereas the area postrema had a very low density. These data suggest that 5HT1A receptors are organized in a manner consistent with the cytoarchitectural and hodological parcellation of the NTS into individual subnuclei. The high concentrations of 5HT1A receptors in the central and intermediate subnuclei suggest a role for these receptors in medullary reflex pathways subserving deglutition. The relatively high density of 5HT1B receptors in the ventrolateral subnucleus suggests that these receptors modulate respiratory neurons, whereas the diffuse organization of 5HT1B receptors in the remaining subnuclei suggests that they are associated with central 5HT afferent pathways to the NTS. Further studies will be required to understand the physiologic role of 5HT1 receptors within the NTS.
Effects of cochlea removal on GABAergic terminals in nucleus magnocellularis of the chicken
Authors: Code Rebecca A. , Durham Dianne , Rubel Edwin W. 
Published: January 2005

AbstractThe effects of unilateral cochlea removal on GABA‐immunoreactive (GABA‐I) terminals in nucleus magnocellularis (NM) of the chick were assessed by immunocytochemical (ICC) techniques. Posthatch chicks (5–8 days old) survived from 1–37 days following unilateral cochlea removal. In the ipsilateral NM, the density of GABA‐I terminals appeared to increase relative to normal controls. 10–37 days after cochlea removal. However, most of that increase could be attributed to a decrease in cell size, cell number, and volume of the nucleus as a result of deafferentation. In the contralateral NM, the density of GABA‐I terminals decreased relative to the ipsilateral NM and to normal animals 1–21 days after cochlea removal. The number of GABA‐I terminals per NM neuron also decreased in the contralateral NM while that in the ipsilateral NM was comparable to normal controls. To ascertain whether these changes represented changes in the number of terminals or in the amount of GABA contained within the terminals, we also examined these terminals using an antibody to glutamic acid decarboxylase (GAD), the biosynthetic enzyme for GABA. Following unilateral cochlea removal, there was no difference in the density of GAD‐I terminals in NM between the two sides of the brain for any of the survival times. Similarly, bilateral cochlea removal had no discernible effect on the density of GABA‐I terminals in NM. These data suggest that unilateral deafferentation may temporarily downregulate the biosynthesis of GABA in the contralateral NM.
Immunohistochemical distribution of calcium‐activated neutral proteinases and endogenous CANP inhibitor in the rabbit hippocampus
Authors: Fukuda Takaichi , Adachi Eijiro , Kawashima Seiichi , Yoshiya Ikuto , Hashimoto Paulo H. 
Published: January 2005

AbstractIntracellular accumulation of Ca2+ after brain ischemia is regarded as one of the principal causes of neuronal death, but details of the intracellular events occurring after Ca2+ accumulation have not yet been described. We propose that a calcium‐activated neutral proteinase which can degrade neuronal cytoskeletal proteins might link Ca2+ accumulation and irreversible injury of the neuronal intracellular structure. First, therefore, we examined the distribution of calcium‐activated neutral proteinase in normal brains.Immunohistochemical distribution of calcium‐activated neutral proteinases (CANP) with high and low sensitivity to Ca2+ (m̈CANP and mCANP) and of endogenous CANP inhibitor was investigated in the dorsal hippocampus of the rabbit. μCANP‐immunoreactivity was detected in almost all of the pyramidal cells and granule cells and in some other neurons. A full‐length staining from perikarya to dendrites was shown in μCANP ‐positive neurons.mCANP‐immunoreactivity was found mainly in four kinds of hippocampal interneurons: (1) basket cells in the stratum oriens of Ammon's horn, (2) pyramidal basket cells at the boundary of pyramidal cell layer and stratum oriens, (3) polymorphic cells in the hilar region of dentate gyrus, and (4) pyramidal or fusiform basket cells at the inner boundary of the granule cell layer and the hilar region. The distribution of these four kinds of neurons was similar to that of parvalbumin‐containing GABAergic neurons.CANP inhibitor immunoreactivity was confined to pyramidal cells in the CA3–CA3c region and some hilar neurons. Neuropil areas corresponding to commissural and association fiber terminals from CA3 pyramidal cells and hilar neurons, i.e., stratum radiatum and stratum oriens of CA1 to CA3c, and the inner part of dentate molecular layer, also exhibited the CANP inhibitor immunoreactivity.The above‐mentioned CANP and inhibitor distribution is discussed in relation to the selective vulnerability of hippocampal neurons to ischemia.
Spatial and morphological differentiation of trigger zones in afferent fibers to the teleost utricle
Authors: Saidel William M. , Popper Arthur N. , Chang Janet S. 
Published: January 2005

AbstractA morphological correlate of the trigger site (the locus of action potential initiation) was identified in afferent axons of the utricle in the ear of two species of teleost fish. These sites were identified by the ferric‐ferrocyanide (Prussian blue) cytochemical procedure and they were correlated with the geometries of afferent intraepithelial arbors as visualized by means of a silver stain.The intraepithelial arbors of afferent fibers show regional distributions that correlate with axon diameter and Prussian blue staining. Afferent axons with diameters greater than 4–5 μm only innervate the striola regions of the epithelium and terminate as one of two distinct types of intraepithelial arbors. Afferent axons with diameters smaller than 4 μm are ubiquitously distributed throughout the epithelium.Arbors that stained by Prussian blue within the utricular epithelium are restricted to the striolar regions. These arbors possess nodal‐like membrane in different branches as postsynaptic membrane. Afferents that innervate hair cells in the extrastriolar epithelial regions stained with Prussian blue only at the extraepithelial terminal heminode. The postsynaptic membrane of these afferents is passive or dendritic‐like.
Dendritic morphologies of retinal ganglion cells projecting to the lateral geniculate nucleus in the rabbit
Authors: Pu Mingliang , Amthor Franklin R. 
Published: January 2005

AbstractSmall injections of fluorescent Rhodamine‐latex microspheres and Fast Blue were made into the dorsal lateral geniculate nucleus (dLGN) of fifteen rabbits. After 8–15 day survival times, the somas of projecting ganglion cells were found to be labelled in the contralateral retinas by retrograde transport. The dendritic morphologies of the labelled ganglion cells were revealed by intracellular injection of Lucifer Yellow or horseradish peroxidase while superfusing the retinas. At least ten distinct dendritic morphologies were observed among 161 injected ganglion cells. The three most commonly recovered dendritic morphologies were those of: (1) alpha‐like cells; (2) large, complex dendritic field cells; and (3) cells with small, dense dendritic fields that resemble intracellularly identified brisk sustained cells (Amthor et al., J. Comp. Neurol. 1989; 280:72–96). Smaller percentages of cells whose dendritic morphologies resembled those of several physiologically identified sluggish and complex receptive field ganglion cell classes (Amthor et al, J. Comp. Neurol. 1989; 280:72–96, 97–21) were also recovered. Several morphological types were also found that were previously unknown or could not be confidently related to those of previously known classes. Most dLGN injections labelled many different types of ganglion cells, but restricted injections in some dLGN loci labelled only a limited number of ganglion cell classes.
Restoration of thalamostriatal projections in rat neostriatal grafts: An electron microscopic analysis
Authors: Xu Z. C. , Wilson C. J. , Emson P. C. 
Published: January 2005

AbstractThe thalamostriatal projections to rat neostriatal grafts were studied by using the Phaseolus vulgaris‐leucoagglutinin (PHA‐L) axonal tracing technique. Two to 6 months after implantation of striatal primordia into adult neostriata, PHA‐L was injected into two different portions of the intralaminar nuclear complex of the thalamus.In the host neostriatum, labeled fibers from the parafascicular nucleus (PF) arborized in a large region in the neostriatum, but avoided small patchlike areas. Most of the fibers from PF had irregular curved trajectories with short side branches that formed boutons. Labeled fibers from the centromedial and paracentral nuclei (CeM‐PC) projected to a similarly large area within the neostriatum but did not show any nonuniformity. CeM‐PC axons had relatively straight trajectories and formed boutons en passant.Both sets of thalamostriatal projection fibers were found in the grafts. Some of the labeled fibers in the grafts formed dense, focal arborizations. Compared to the host neostriatum, the distribution of postsynaptic elements in the grafts was altered dramatically. In the host neostriatum, 89% of the terminals from PF terminated onto dendritic shafts; 93% of the CeM‐PC terminals contacted dendritic spines. However, only 47% of the PF terminals in the grafts contacted dendritic shafts; 53% of them terminated on dendritic spines. In grafts, 81% of the terminals from CeM‐PC region contacted dendritic spines; 19% of them made synapses on dendritic shafts.The shift of postsynaptic elements in the grafts suggests a loss of pathway specificity in the induction of dendritic spines on neostriatal neurons in grafts.
Estradiol increases the number of nuclear pores in the arcuate neurons of the rat hypothalamus
Authors: Perez Julio , Hernandez Pedro , Garcia‐Segura Luis M. 
Published: January 2005

AbstractFreeze‐fracture replicas of hypothalamic arcuate neurons and of Purkinje and granule cells of the cerebellar cortex from adult female rats were assessed in order to test the possible influence of estradiol on nuclear pores. Rats were ovariectomized and injected either with estradiol or with vehicle. An additional group of rats in proestrus was also studied. Pore diameter was not affected by ovariectomy or estrogen treatment. In arcuate neurons, the number of nuclear pores per nuclear membrane area, the total number of pores per nucleus, and the percentage of nuclear pores arranged in clusters were decreased by ovariectomy and increased within 30 minutes after estradiol administration to ovariectomized rats. The effect of estradiol on nuclear pores was sustained for several days; the number of pores and the percentage of pores in clusters reverted to control values by 1 month after the hormonal treatment. None of the above mentioned changes was observed in Purkinje and granule cells of the cerebellar cortex. These results indicate that estradiol may modulate the number and distribution of nuclear pores in arcuate neurons and suggest that the modification of the ultrastructure of the nuclear envelope may be one of the first effects of gonadal steroids on target cells.