bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunohistochemical identification of neurons in ganglia of the guinea pig sphincter of oddi
Authors: Wells David G. , Talmage Erin K. , Mawe Gary M. 
Published: January 2005

AbstractThe sphincter of Oddi is a smooth muscle sphincter that regulates the flow of bile into the duodenum. To identify potential chemical coding in sphincter of Oddi neurons, immunohistochemistry and histochemistry were employed to assay for putative neurotransmitters and related synthetic enzymes in wholemount preparations, with and without colchicine treatment. Immunoreactivities for enkephalin‐endorphin (ENK‐END), substance P (SP), nitric oxide synthase, vasoactive intestinal peptide (VIP), neuropeptide Y (NPY), and calcitonin generelated peptide (CGRP) were demonstrated within the ganglionated plexus. Roughly half of the neurons in the sphincter of Oddi expressed immunoreactivity for both SP and ENK‐END, but not for nitric oxide synthase. About 25% of the neurons expressed nitric oxide synthase immunoreactivity as well as NADPH‐diaphorase activity. This contingent of neurons was made up of two subgroups: one that expressed immunoreactivity for VIP, the other for NPY. Neurons that expressed CGRP immunoreactivity were sparse in sphincter of Oddi ganglia; however, many axons immunoreactive for both CGRP and SP were present in the ganglionated plexus. The CGRP/SP fibers are probably visceral afferents that may influence ganglionic output through axon reflex circuits. These results, along with studies of the actions of these neuroactive compounds on sphincter tone, support the view that ganglia of the sphincter of Oddi are largely comprised of excitatory (SP/ENK‐END‐immunoreactive) and inhibitory (nitric oxide synthase/VIP‐ or NPY‐immunoreactive) neurons, and that sphincter of Oddi tone is controlled by the regulation of the outputs of these two groups of cells. © 1995 Wiley‐Liss, Inc.
Insulin‐like growth factor‐1 mRNA is increased in deafferented hippocampus: Spatiotemporal correspondence of a trophic event with axon sprouting
Authors: Guthrie Kathleen M. , Nguyen Thomas , Gall Christine M. 
Published: January 2005

AbstractDeafferentation is known to induce axonal sprouting in adult brain, but the signals that direct this response are not understood. To evaluate the possible roles of insulin‐like growth factor‐1 (IGF‐1) and basic fibroblast growth factor (bFGF) in central axonal sprouting, the present study used in situ hybridization to evaluate IGF‐1 and bFGF mRNA expression in entorhinal deafferented rat hippocampus. Alternate tissue sections were processed for Fink‐Heimer impregnation of axonal degeneration, Bandeiraea simplicifolia (BS‐1) labeling of microglia, and glial fibrillary acidic protein immunocytochemistry. In control hippocampus, IGF‐1 mRNA was localized to a few neurons, with no labeled cells in the dentate gyrus molecular layer; bFGF cRNA hybridization was diffuse in dendritic fields but was dense in CA2 stratum pyramidale. Both mRNA species were increased by deafferentation. The distribution of elevated IGF‐1 mRNA corresponded precisely to fields of axonal degeneration and was greatest in the dentate gyrus outer molecular layer and stratum lacunosum moleculare. In these fields, IGF‐1 mRNA was elevated by 2 days, reached maximal levels at 4 days, and declined by 10 days postlesion. Double labeling revealed that the majority of IGF‐1 cRNA‐labeled cells were microglia. In deafferented hippocampus, bFGF mRNA was broadly increased across fields both containing and lacking axonal degeneration. In the dentate, bFGF mRNA levels peaked at 5 days postlesion and remained elevated through 14 days. These results demonstrate that reactive microglia within deafferented hippocampal. Laminae express IGF‐1 mRNA just prior to and during the period of reactive axonal growth and suggest that IGF‐1 plays a role in directing the sprouting of spared afferents into these fields. © 1995 Wiley‐Liss, Inc.
Barrelfield of the prenatally X‐irradiated rat somatosensory cortex: A histochemical and electrophysiological study
Authors: Ito Muneyuki 
Published: January 2005

AbstractThe effect of prenatal X‐irradiation on the vibrissal cortical barrelfield of the brain of rats exposed to 200 R on the embryonic day 17 was studied morphologically and electrophysiologically. Cytoarchitectural barrels fail to appear in adult rats that have been subjected to this in utero treatment. However, sections cut in a plane tangential to the vibrissal cortex and examined for cytochrome oxidase (CO), a mitochondrial enzyme, contained a matrix of patterned CO activity which, albeit smaller and weaker in intensity, is similar to CO barrels in normal controls. Current source density analysis of cortical field potentials indicated that, as in the normal cortex, the earliest sink following peripheral stimulation appears in association with this high CO activity. These results suggest that the specific vibrissal thalamocortical pathway sets up an excitatory synaptic activity in the cortex of the irradiated animal. Efficacy of this route in eliciting postsynaptic spikes in the cortical output neurons was confirmed by recording extracellular spike responses to vibrissa displacements from layer Vb pyramidal neurons that were then injected intracellularly with horseradish peroxidase for later anatomical identification. © 1995 Wiley‐Liss, Inc.
Efferent connections of the lateral cortex of the lizard gekko gecko: Evidence for separate origins of medial and lateral pathways from the lateral cortex to the hypothalamus
Authors: Hoogland Piet V. , Vermeulen‐Vanderzee Eefke 
Published: January 2005

AbstractThe lateral cortex of the lizard Gekko gecko is composed of three parts: a dorsal and ventral part located rostrally and a posterior part located caudally. In order to obtain detailed information about the efferent connections of these lateral cortex subdivisions, iontophoretic injections of the anterograde tracers Phaseolus vulgaris leucoagglutinin and biotinylated dextran were made in the various parts. The main projection from the dorsal part terminates in the caudal part of the medial cortex. Other cortical projections were noted to the ipsi‐ and contralateral lateral cortex, the large‐celled part of the medial cortex, and the dorsal cortex. Additional fibers were found bilaterally in the anterior olfactory nucleus and the external amygdaloid nucleus. The ventral part of the lateral cortex projects mainly to the ipsilateral, posterior part of the dorsal ventricular ridge and the external amygdaloid nucleus. Minor contralateral projections to these nuclei were also found. Other projections were observed to travel to the caudal part of the medial cortex, to the nucleus sphericus, and bilaterally to the lateral cortex and the anterior olfactory nucleus.The posterior part of the lateral cortex has similar efferent connections as the dorsal part and should be regarded as the caudal continuation of the dorsal part.Because previous studies have shown that the medial cortex and the amygdaloid complex project to different hypothalamic areas, we conclude that the dorsal and ventral parts of the lateral cortex transmit olfactory information to separate hypothalamic areas that are probably involved with different types of behavior. © 1995 Wiley‐Liss, Inc.
Secretory pathways of neuropeptides in rat lumbar dorsal root ganglion neurons and effects of peripheral axotomy
Authors: Zhang Xu , Åman Katarina , Hökfelt Tomas 
Published: January 2005

AbstractUsing immunocytochemistry combined with confocal and electron microscopy, the secretory pathways related to substance P (SP), calcitonin gene‐related peptide (CGRP), galanin (GAL), and neuropeptide Y (NPY) were investigated in neurons in rat lumbar (L) 4 and L5 dorsal root ganglia (DRGs) before and after peripheral axotomy. All four peptides were processed through the regulated secretory pathway in many small neurons in normal DRGs, and CGRP through this pathway also in some large neurons. In many small neurons, two neuropeptides could be sorted into the same or separate large dense‐core vesicles (LDCVs). The LDCVs had a significantly larger diameter in small as compared to large DRG neurons. Fourteen days after sciatic nerve cut, the levels of SP‐ and CGRP‐like immunoreactivities (‐LIs) and the number of LDCVs containing these peptides were markedly reduced, but SP‐ and CGRP‐LIs were still seen in the regulated pathway. GAL‐LI was markedly increased in many small neurons and some large neurons and NPY‐LI mainly in large neurons. Both peptides were particularly abundant in the Golgi region. In small neurons, the number of LDCVs containing GAL‐ or NPY‐LI was increased, but did not appear to reach the numbers containing SP‐ or CGRP‐LI in normal DRG neurons. After axotomy, CGRP‐LI and GAL‐LI were often in separate LDCVs. One type of NPY‐positive large neurons showed budding off of LDCVs after axotomy, but also some “scattered” labeling in the cytoplasm. In the second type, NPY‐LI was mainly found in multivesicular bodies. In several myelinated nerve fibers a “diffuse” distribution of NPY was seen together with some LDCVs containing NPY‐LI. In contrast, in unmyelinated nerve fibers, NPY‐, GAL‐, SP‐, and CGRP‐LIs were always observed in LDCVs. Thus, both in normal and axotomized DRG neurons, peptides are processed through the regulated pathway. However, in some large neurons, NPY is, in addition, secreted through the constitutive pathway, perhaps as a consequence of limited sorting mechanisms for NPY, i.e., the plasticity of the secretory mechanisms does not match the rate of peptide synthesis after axotomy. © 1995 Wiley‐Liss, Inc.
Afferent reorganisation within the superior olivary complex of the gerbil: Development and induction by neonatal, unilateral cochlear removal
Authors: Russell F. Anne , Moore David R. 
Published: January 2005

AbstractCochlear removal in young animals has been shown to produce a variety of degenerative and generative effects within the auditory brainstem. A primary target for axons of neurons in the anteroventral cochlear nucleus (AVCN) is the superior olivary complex (SOC). Following unilateral cochlear removal in neonatal gerbils, AVCN neurons on the side of the removal die, and axons deriving from the AVCN on the unlesioned side produce new endings that innervate previously inappropriate target zones within the ipsilateral medial nucleus of the trapezoid body, both medial superior olives, and the contralateral lateral superior olive. In this study, we have used the anterograde transport of Dil and HRP from the AVCN to relate the formation of these endings to the time course of normal development in the gerbil brainstem. We have also examined the effects of cochlear removal at different ages, and survival to various ages after the removal, to define the time course for these generative phenomena. The results show that, while the major projection pathways from the AVCN to the SOC are in place at the time of birth, further and subtle development of AVCN terminal arbors occurs during the first postnatal week. This overlaps with the time during which cochlear removal produces the formation of exuberant afferents to the SOC from the intact AVCN. The exuberant afferents form through axon sprouting rather than through a suppression of normal, developmental regression. They appear to innervate tonotopically appropriate target regions within the SOC. The formation of the novel afferents begins within 3 days of the removal and appears to be complete within a further 5–7 days. By postnatal day (P) 10, both the normal development of the AVCN to SOC projection and the potential for alteration of that projection by removal of the contralateral. Cochlea appear to be over. These results suggest that the potential for forming novel projections in the gerbil auditory brainstem is lost before the onset of functional hearing (at P12) and is, therefore, unlikely to result from changes in auditory experience. © 1995 Wiley‐Liss, Inc.
Subcompartmental organization of the ventral (protrusor) compartment in the hypoglossal nucleus of the rat
Authors: Aldes Leonard D. 
Published: January 2005

AbstractThe extent and myotopic organization of the ventral (protrusor) compartment of the hypoglossal nucleus (nXII) in the rat is controversial. Of particular concern is the location of motoneurons that innervate the intrinsic (verticalis, transversus) as compared to extrinsic (genioglossus) tongue protrusor muscles. These issues were investigated with retrograde transport, lesion /degeneration /immunocytochemical, and classic Golgi staining techniques.Results from these experiments demonstrate the following: (1) the ventral compartment extends the entire rostrocaudal length of nXII and is organized into three longitudinally oriented subcompartments, one medial and one lateral within the boundaries of nXII, and one outside the confines of nXIL defined as the lateral accessory subcompartment; (2) the medial and lateral subcompartments contain motoneurons that innervate the intrinsic (verticalis, transversus) and extrinsic (genioglossus) tongue protrusor muscles, respectively, while the lateral accessory subcompartment innervates the geniohyoid muscle; (3) ventral subcompartments are unequal in size and vary along the rostrocaudal dimension of nXII. The medial subcompartment is largest caudally and smallest rostrally, while the converse is true for the lateral subcompartment. By contrast, the lateral accessory subcompartment is present only along the caudal one‐half of nXII; (4) medial and lateral subcompartments are further organized into smaller subgroups. Medial and centromedial subgroups are discernible within the medial subcompartment, lateral and centrolateral subgroups within the lateral subcompartment. Both medial and lateral subgroups extend throughout the rostrocaudal length of nXII, whereas the centromedial and centrolateral subgroups are present only along the middle two‐thirds of nXII where they form a central motoneuron band; (5) there is an inverse myotopic organization within the medial and lateral subcompartments such that proximal and distal portions of intrinsic and extrinsic protrusor muscles receive innervation from rostral and caudal motoneurons, respectively; and (6) there is a correlation between motoneuron morphology (size, shape and dendritic field domains), subcompartment localization, and myotopic specificity. Motoneurons in the medial subcompartment are small (X̄ = 23. 08 μm), round to globular, with dendrites oriented medially, dorsomedially, dorsolaterally, and caudally, whereas lateral subcompartment motoneurons are large (X̄ = 29. 49 μm), round to triangular, with dendrites directed mainly mediolaterally and dorsally.These data are relevant to understanding the functional organization of nXII and the motor control of the tongue. Results are further discussed relative to the convergence of multifunctional afferent systems in the ventromedial subcompartment of nXII. © 1995 Wiley‐Liss, Inc.
Morphology of developing rat genioglossal motoneurons studied in vitro: Relative changes in diameter and surface area of somata and dendrites
Authors: Núñez‐Abades P. A. , Cameron W. E. 
Published: January 2005

AbstractThis study describes the postnatal change in size of motoneurons in the hypoglossal nucleus that innervate the genioglossus muscle. Such anatomical information is essential for determining the cellular mechanisms responsible for the changes observed in the electrical properties of these motoneurons during postnatal development. The cells analyzed here are part of an earlier study (Núñez‐Abades et al. [1994] J. Comp. Neurol. 339:401–420) where 40 genioglossal (GG) motoneurons from four age groups (1–2, 5–6, 13–15, and 19–30 postnatal days) were labeled by intracellular injection of neurobiotin in an in vitro slice preparation of the rat brainstem and their cellular morphology was reconstructed in three‐dimensional space.The sequence of postnatal dendritic growth can be described in two phases. The first phase, between birth (1–2 days) and 13–15 days, was characterized by no change in either dendritic, diameter (any branch order) or dendritic surface area of GG motoneurons. However, maturation of the dendritic tree produced more surface area at greater distances from the soma by redistributing existing membrane (retracting some terminal branches). During the second phase, between 13–15 days and 19–30 days, the dendritic surface area doubled as a result of an increase in the dendritic diameter across all branch orders and a generation of new terminal branches. In contrast to the growth exhibited by the dendrites, there was little discernible postnatal growth of somata.At all ages, dendrites of GG motoneurons show the largest amount of tapering in the firstand second‐order dendrites. The calculated dendritic trunk parameter deviated from a value 1.0, indicating that the dendritic tree of developing GG motoneurons cannot be modeled accurately as an equivalent cylinder. However, the value of this parameter increased with age. Strong correlations were found between the diameter of the first‐order dendrite and the dendritic surface area, dendritic volume, combined dendritic length, and, to a lesser extent, the number of terminal dendrites in GG motoneurons. Correlations were also found between somal and dendritic geometry but only when data were pooled across all age groups.These data support earlier studies on kitten phrenic motoneurons, which concluded that postnatal growth of motoneurons was not a continuous process. Based on the fact that there was no growth in the first 2 weeks, the changes in the membrane properties described during this phase of postnatal development (e.g., decrease in input resistance) cannot be attributed to increases in the total membrane surface area of these motoneurons. It is proposed that these changes result from changes in the specific membrane resistance of these neurons. © 1995 Wiley‐Liss, Inc.
Non‐NMDA glutamate receptors are present throughout the primate hypothalamus
Authors: Ginsberg Stephen D. , Price Donald L. , Blackstone Craig D. , Huganir Richard L. , Martin Lee J. 
Published: January 2005

AbstractTo determine the distributions of glutamate receptors throughout the macaque hypothalamus, we utilized highly specific antipeptide antibodies to visualize α‐amino‐3‐hydroxy‐5‐methyl4‐isoxazole propionate receptor subunits (GluRl, GluR2 and GluR3 {designated as GluR2/3}, and GluR4); kainate receptor subunits (GluR6 and GluR7, {Idesignated as GluR6/7}), and a metabotropic receptor (mGluRlα). The results indicate that these glutamate receptors are distributed differentially throughout the monkey hypothalamus. α‐Amino‐3‐hydroxy‐5‐methyl‐4‐isoxazole propionate receptors are the dominant non‐N‐methyl‐D‐aspartate glutamate receptors within the monkey hypothalamus, and the GluR2 subunit is most abundant. GluR1‐immunoreactive neurons and neuropil are observed predominantly in the tuberal and mammillary nuclei. GluR2/3‐immunoreactive neurons and neuropil have a broader distribution within preoptic, anterior, tuberal, and caudal regions. Separate (but partially overlapping) distributions of GluRl‐ and GluR2/3‐immunoreactive neurons were found, suggesting that the GluR1, GluR2, and/or GluR3 subunits may be coexpressed in subsets of hypothalamic neurons. In contrast, GluR4 immunoreactivity was expressed minimally within monkey hypothalamus. GluR6/7 immunoreactivity was enriched selectively within the suprachiasmatic nucleus. mGluRlα immunoreactivity was present in the mammillary complex. The localization of non‐N‐methyl‐D‐aspartate glutamate receptor subunits to neurons throughout the macaque hypothalamus provides further evidence for the glutamatergic regulation of neuroendocrine, autonomic, and limbic circuits. Differential distributions of glutaniate receptor subunits may increase the dynamic range of the effects of presynaptic glutamate, allowing for the regulation of several distinct functions subserved by hypothalamic neurons. © 1995 Wiley‐Liss, Inc.
Fibroblast growth factor‐2‐like immunoreactivity in auditory brainstem nuclei of the developing and adult rat: Correlation with onset and loss of hearing
Authors: Riedel Bettina , Friauf Eckhard , Grothe Claudia , Unsicker Klaus 
Published: January 2005

AbstractFibroblast growth factor‐2 (FGF‐2; basic FGF) is widely distributed in the developing and adult brain and has numerous effects on cultured and lesioned neural cells. The physiological role of FGF‐2 in the unlesioned nervous system, however, is still not understood. We have studied the distribution of FGF‐2 in the developing, adult, and functionally impaired central auditory system of the rat using specific antibodies and peroxidase‐antiperoxidase immunocytochemistry. FGF‐2‐like immunoreactivity (FGF‐2‐IR) occurred in neuronal cell bodies and/or nerve fibers but was very rarely observed in glial cells. Several auditory brainstem nuclei, including the superior paraolivary nucleus, the medial superior olive, the lateral and ventral trapezoid nuclei, and the central nucleus, as well as the external cortex of the inferior colliculus, were entirely devoid of FGF‐2‐IR. In the dorsal cochlear nucleus, the lateral superior olive, and the nuclei of the lateral lemniscus, FGF‐2‐IR was not detectable in nerve cell bodies prior to adult age. Neurons in the medial geniculate body exhibited FGF‐2‐IR only transiently, from postnatal day (P) 5 until P16. Neurons in the medial nucleus of the trapezoid body were immunoreactive from P8 onwards. FGF‐2‐IR in anteroventral and posteroventral cochlear neurons disappeared at P14, i. e., at the onset of hearing, but immunoreactivity returned after P21. A transient expression of FGF‐2 around the time when hearing function commences was observed in the dorsal cortex of the inferior colliculus. Thus, regulation of neuronal FGF‐2‐IR in several, but not all, auditory, nuclei is related to the onset of hearing, in that IR disappears at that time or transiently appears. This suggests a causal link between the onset of hearing and FGF‐2 expression. In support of this notion, ototoxic treatment with gentamycin abolished FGF‐2‐IR in the P16 medial geniculate body but not in other auditory brainstem centers. Thus, FGF‐2 may be considered a regulator or indicator of the acquisition of functional activity and responsiveness to sensory stimuli in several areas of the auditory system. © 1995 Wiley‐Liss, Inc.