bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunoreactivity in Limulus: III. Morphological and biochemical studies of FMRFamide‐like immunoreactivity and colocalized substance P‐like immunoreactivity in the brain and lateral eye
Authors: Lewandowski Thomas J. , Lehman Herman K. , Chamberlain Steven C. 
Published: January 2005

AbstractFMRFamide‐like immunoreactivity (FLI) and the colocalization of FMRFamide and subtance P‐like (SPLI) immunoreactivities were examined in the brain and lateral eye of the horseshoe crab with FITC‐ and TRITC‐ labeled secondary antibody techniques. In the brain, fibers with FLI were localized in the neuropils of the lamina, medulla, central body, corpus pedunculatum, optic tract, circumesophageal connective, and central neuropil. An extensive network of reactive fibers innervates the brain's vascular sheath. Somata with FLI were found in the dorsal medial group, dorsal lateral posterior groups #1 and #2, and ventral posterior lateral groups #1 and #2. Several distinct subgroups of reactive somata were noted in both the medullar and ventral medial groups.The distribution of fibers in the brain with colocalized FLI and SPLI includes those which innervate the vascular sheath and widespread populations of small‐diameter beaded fibers in the central neuropil and circumesophageal connective. Somata with colocalized FLI and SPLI constitute minority populations in the medullar and dorsal medial groups but form the majority population of a subgroup in the ventral medial group.Overall localization of SPLI was reevaluated and is reported here according to the nomenclature of the new Chamberlain and Wyse brain atlas. In addition to those previously reported, somata with SPLI were found in the dorsal lateral posterior groups #1 and #2, the ventral lateral posterior groups #1 and #2, and several distinct subgroups of the medial and ventral medial groups.In the retina of the lateral eye, fibers with both FLI and SPLI ramify in the lateral plexus and ultimately innervate the corneal epidermis.Brain homogenates were examined for immunoreactive (ir) FMRFamide and ir–substance P with radioimmunoassay techniques. Ir‐FMRFamide and ir–substance P eluted in different fractions from both gel filtration chromatography and HPLC. Furthermore, the binding curves for both substances were similar to those of the corresponding synthetic compounds.Brain homogenates were also bioassayed on the lateral eye. Three gel filtration fractions mimic natural circadian activity by increasing the sensitivity of the lateral eye, but they were not coincident with ir‐FMRFamide or ir–substance P. Although it is not completely resolved what the active molecules in these fractions are, it is clear that neither ir‐FMRFamide nor ir–substance P is a possible candidate.
Serotonin immunoreactivity in the optic lobes of the sphinx moth Manduca sexta and colocalization with FMRFamide and SCPB immunoreactivity
Authors: Homberg U. , Hildebrand J. G. 
Published: January 2005

AbstractIn the optic lobes (OLs) of the sphinx moth Manduca sexta, 300–350 neurons per hemisphere are immunoreactive with an antiserotonin antiserum. Two groups of weakly serotonin‐immunoreactive cells (OL1) appear to be amacrine cells of the medulla, whereas more intensely immunoreactive cells (OL2) are probably centrifugal neurons that innervate the lobula, medulla, and lamina, as well as the superior protocerebrum. At least one other OL2 cell is a local optic‐lobe interneuron with arborizations in the dorsal medulla and lobula. The serotonin‐immunoreactive cells are also immunoreactive with an antiserum against Drosophila melanogaster DOPA decarboxylase. All OL2 cells, but not the OL1 cells, are furthermore immunoreactive with an anti‐FMRFamide antiserum and an anti‐SCPB antiserum. This suggests that neuropeptides related or identical to FMRFamide and SCPB are colocalized and may serve as cotransmitters with serotonin in OL2 optic‐lobe interneurons.
Organization of afferent and efferent pathways in the pudendal nerve of the female cat
Authors: Thor K. B. , Morgan C. , Nadelhaft I. , Houston M. , de Groat W. C. 
Published: January 2005

AbstractApplication of horseradish peroxidase to the pudendal nerve in the female cat labelled lumbosacral afferent and efferent neurons and their processes. Afferent axons entered the spinal cord primarily at the S1 and S2 segments and traveled rostrocaudally in Lissauer's tract and the dorsal columns. A distinctive component of the dorsal column projection was located at the lamina I‐dorsal column border as a densely labelled, compact bundle that distributed fibers to the dorsal horn at spinal levels near the segments of entry of the afferent axons. Afferent terminal labelling was located in the marginal zone, the intermediate gray matter, and the dorsal gray commissure in the lumbosacral and coccygeal spinal cord. A well‐defined terminal field restricted to the S1 and rostral S2 segments was present in the medial third of the nucleus proprius and substantia gelatinosa. Labelled motoneurons in Onuf's nucleus (S1 and S2) exhibited longitudinal dendrites that extended rostrocaudally within the nucleus and three groups of transverse dendrites that emanated periodically from the nucleus and passed to the ventrolateral funiculus, the intermediate gray, and the dorsal gray commissure. Components of the pudendal nerve that innervate the anal and urethral sphincters were also labelled by injecting HRP into the respective sphincter muscles. Motoneurons innervating the anal and urethral sphincters were located in the dorsomedial and ventrolateral divisions, respectively, of Onuf's nucleus. Afferent projections from the two sphincters were similar; the most prominent terminations were present in the marginal zone, intermediate gray, and dorsal gray commissure. These results are discussed with respect to the physiological function of the pudendal nerve and its relationship with sacral autonomic pathways.
Primate spinothalamic pathways: II. The cells of origin of the dorsolateral and ventral spinothalamic pathways
Authors: Apkarian A. Vania , Hodge Charles J. 
Published: January 2005

AbstractThe cells of origin of the dorsolateral (DSTT) and the ventral (VSTT) spinothalamic tracts were studied in 11 monkeys. The spinothalamic tract cells were retrogradely labeled by horseradish peroxidase (HRP) injected in the thalamus. All animals also received a midthoracic spinal cord lesion on the side ipsilateral to the thalamic injections.The distribution of labeled cells found in these animals throughout the cervical segments was similar to animals with no spinal cord lesions. Five animals had ventral quadrant lesions to demonstrate the cells of origin of the DSTT. In macaques with complete ventral quadrant lesions, more than 80% of the HRP label in the contralateral L4–L7 segments was located in lamina I, while in squirrel monkeys, the label in the contralateral lower lumbar region was distributed between laminae I–III and IV–VI. Few labeled cells were found in laminae VII–X.Six animals received dorsolateral funiculus lesions to demonstrate the cells of origin of the VSTT. In animals with adequate lesions, 84–99% of the contralateral HRP label in L4–L7 was located in laminae IV–X. Macaques had a larger percentage of labeled cells located in lamina I than squirrel monkeys.The results indicate the existence of two spinothalamic pathways in the primate. The DSTT was calculated to compose about one fourth of the total spinothalamic population.
Novel peptide pancreastatin: Its occurrence and codistribution with chromogranin a in the central nervous system of the pig
Authors: Kar S. , Bretherton‐Watt D. , Gibson S. J. , Steel J. H. , Gentleman S. M. , Roberts G. W. , Valentino K. , Tatemoto K. , Ghatei M. A. , Bloom S. R. , Polak J. M. 
Published: January 2005

AbstractThe distribution of pancreastatin immunoreactivity was investigated in porcine brain, spinal cord, dorsal root ganglia, and pituitary. In the brain, immunoreactive cell bodies were present in many areas including the cortex, basal ganglia, hippocampus, thalamus, hypothalamus, mesencephalic reticular formation, cerebellum, and medulla oblongata. Immunoreactive fibres were most abundant in the globus pallidus, stria terminalis, entopeduncular nucleus, hippocampus, and in the substantia nigra. In the spinal cord, immunoreactive cells were found in laminae IV±IX. Immunoreactive fibres were concentrated in the dorsal horn. Pancreastatin immunoreactivity was localised to fibres and small cells (5–10% of the total) in the dorsal root ganglia. In the posterior pituitary, many immunoreactive fibres were present and in the anterior lobe subsets of gonadotrophs and thyrotrophs were pancreastatin‐immunoreactive. The localisation of pancreastatin showed a parallel distribution with chromogranin A. Coexistence of pancreastatin with calcitonin generelated peptide (CGRP) immunoreactivity in cell bodies in the spinal cord, including motoneurones, and with CGRP or galanin immunoreactivities in dorsal root ganglion cells was also noted. The differential pattern of pancreastatin immunostaining was reflected in the extractable levels of peptide with highest concentrations in the cortex (55.8 ± 6.0 pmol/g wet weight, mean ± S.E.M.), thalamus (60.0 ± 5.0 pmol/g), hypothalamus (54.4 ± 6.5 pmol/g), and anterior pituitary (2,714 ± 380 pmol/g). Characterisation of pancreastatin immunoreactivity in the hypothalamus and pituitary by gel permeation and high‐pressure liquid chromatography revealed multiple molecular forms, one of which was indistinguishable from natural porcine pancreastatin. The widespread distribution of pancreastatin immunoreactivity suggests this peptide may play a part in several neuroendocrine, autonomic, somatic, and sensory functions, and its colocalisation with chromogranin A is consistent with a precursor‐product relationship.
Number and size of neurons and synapses in the motor cortex of cats raised in different environmental complexities
Authors: Beaulieu Clermont , Colonnier Marc 
Published: January 2005

AbstractIn a previous study we have shown that the richness of the environment affects the number of neurons, the size of their nuclei, the number of round‐asymmetrical synapses per neuron, the numerical density (number per unit volume; Nv) of flat‐symmetrical synaptic contacts, their number per neuron and their size in the visual cortex of cats. Of these, the number of flat‐symmetrical synapses per unit volume is particularly affected (there are nearly twice as many per mm3 in the impoverished cortex). Several studies in the rat have shown that environmentally induced changes in cortical thickness occur in the occipital regions but are much smaller or absent in the frontal regions. In order to determine if the cat motor cortex is also resistant to environmental changes, we have estimated the number and size of neurons and of synapses in individual laminae of motor cortex, area 4γ, in six pairs of cats raised either in a colony (EC: enriched condition) or in isolation (IC: impoverished condition).For the neurons, we have found that the numerical density (28,900 neurons per mm3 of EC and 29,500 neurons/mm3 of IC motor cortex), the number under 1 mm2 of cortical surface (49,400 and 49,200 in EC and IC cats), and the size of the neuronal nuclei (82 vs 80 μm2 in EC and IC animals) were not significantly affected.The number of flat‐symmetrical synapses per neuron (1,470 in EC vs 1,400 in IC cortex), their size (0.33 μm in both groups) and even their number per unit volume, which was so greatly affected in the visual cortex, remains unchanged (43 million/mm3 and 41 million/mm3 in EC and IC motor cortex). We did find however, a significant difference (p < 0.05) in the numerical density of round‐asymmetrical synapses which is 13% greater in the impoverished motor cortex (216 million/mm3 in EC vs 247 million/mm3 in IC cortex).Our results confirm that the motor cortex is much less affected by the richness of the environment than the visual cortex: In fact, the cat motor cortex is hardly affected at all. Furthermore our results represent the most complete data presently available on the number and size of neurons and synapses in individual laminae of the cat motor cortex.
Cells in laminae III and IV of rat spinal dorsal horn receive monosynaptic primary afferent input in lamina II
Authors: Todd Andrew J. 
Published: January 2005

AbstractIn order to determine how information conveyed by fine primary afferent fibres might reach the deeper laminae of the spinal dorsal horn, 5 Golgistained neurones with somata in lamina III or IV and dendrites that entered lamina II were examined by electron microscopy.Three of the cells were from animals in which 2 or 3 dorsal roots had been cut 26 or 30 hours previously. These cells received numerous synapses in lamina II, and between 13 and 16% of these (24–31% of asymmetric synapses) were from degenerating axons. Synapses with degenerating axons were found throughout the depth of lamina II, including the dorsal part, which receives primary afferent input from myelinated nociceptors and from unmyelinated axons. In addition, all 3 cells were postsynaptic to degenerating axons within lamina III. The 2 cells from unoperated animals also received many synapses within lamina II and at some of these the presynaptic axon was the central terminal of a glomerulus. Only one example of a dendrodendritic synapse involving a stained dendrite was seen. Cells of laminae III and IV may therefore not be a major target for presynaptic dendrites of cells in lamina II.It is concluded that one way in which information carried by primary afferents passes from the superficial dorsal horn to the deeper laminae is through monosynaptic contacts between these afferents and the dorsal dendrites of some cells whose somata are situated in laminae III and IV. If the axons of these cells generate local collaterals, this may account for some of the activation of cells whose dendrites do not enter lamina II.
Auditory cortical projection from the anterior ectosylvian sulcus (Field AES) to the superior colliculus in the cat: An anatomical and electrophysiological study
Authors: Alex Meredith M. , Ruth Clemo H. 
Published: January 2005

AbstractSensory activity in the deep layers of the superior colliculus (SC) is strongly influenced by descending cortical inputs. Elimination (permanent or reversible) of specific regions of visual or somatosensory cortex, known to have direct access to the SC, abolishes or dramatically reduces SC responses to stimuli from those modalities. While many SC neurons are also responsive to auditory cues, the origin of auditory corticotectal connections is not clear at present and their affect on activity in the SC is unknown. Therefore, the present study was undertaken to determine the origin, organization, and functional characteristics of auditory corticotectal projections. Of the auditory cortices (AI; AII; Fields A, P, and VP), only the auditory subregion of the banks of the anterior ectosylvian sulcus (Field AES) showed a robust anatomical projection to the SC. These data were confirmed physiologically: auditory neurons in Field AES projected to the SC and auditory SC neurons responded to stimulation of the Field AES. However, neither anatomical nor physiological techniques revealed a clear topographic relationship between the Field AES and the SC but suggested instead a diffuse and extremely divergent/convergent projection. Stimulation and cryoblockade of Field AES demonstrated the excitatory nature of this corticotectal pathway, whose influence was most evident on SC responses to stimuli of reduced intensity. Given the short latency of this ear‐cortex‐SC circuit and its excitatory influence on unimodal as well as on multisensory auditory neurons, it seems likely that Field AES plays a significant role in facilitating SC responses to auditory stimuli.
Expression of the growth cone specific epitope CDA 1 and the Synaptic vesicle protein SVP38 in the developing mammalian cerebral cortex
Authors: Devoto Stephen H. , Barnstable Colin J. 
Published: January 2005

AbstractCDA 1 is a novel antigen that within the brain is present specifically in neuronal growth cones. Electron microscope immunohistochemistry and subcellular fractionation showed the CDA 1 epitope to be on a cytosolic molecule. In cultured neurons, it is abundant in growth cones and not detectable in neurites or cell bodies.The development of the rat cerebral cortex was investigated by using the monoclonal antibody to CDA 1 and an antibody to SVP38, the synaptic vesicle glycoprotein. CDA 1 immunoreactivity in the rat cerebral cortex peaks just before birth and disappears by postnatal day 12, a few days before the major increase in the number of mature synapses. In contrast, SVP38 is expressed in parallel with the appearance of mature synapses. CDA 1 and SVP38 thus are markers of growth cones and synapses, respectively. Their expression during development reflects some of the structural and functional changes that occur during synapse formation.
New structural features of synapses in the anteroventral cochlear nucleus prepared by direct freezing and freeze‐substitution
Authors: Tatsuoka Hozumi , Reese Thomas S. 
Published: January 2005

AbstractThe rostral anteroventral cochlear nucleus (AVCN) of the chinchilla provides a preparation in which neuronal cell bodies and synapses in the mammalian central nervous system can be examined after direct freezing and freeze‐substitution of rapidly excised brain stem slices. Cell bodies and synapses in the freeze‐substituted AVCN differed from those in perfusion‐fixed AVCN in several interesting respects. Despite of these differences, four types of synaptic terminal were distinguished in freeze‐substituted AVCN and correlated with the four well‐known types of perfusion‐fixed terminal. Since the transmitter at each of the four types of terminal has been tentatively identified, the structure of synaptic vesicles and junctions in the freeze‐substituted terminals could be related to transmitter type. Synaptic vesicles were uniformly round, but their diameters, deployment, and related cytoskeletal elements near the synaptic junction differed in each chemical type of synapse; the synapses thought to be cholinergic, for instance, had only a few vesicles clustered at their presynaptic junctions while the rest of the vesicles were separated from the junction by a network of fine filaments. Two types of filamentous components, short vertical projections from the postsynaptic membrane and thin filaments protruding from these projections, comprised the basic structure of the postsynaptic specialization, but their sizes and distribution differed at each chemical type of terminal. For instance, the postsynaptic specialization at the glycine terminal was distinguished by numerous thin filaments which curved sideways to run parallel to the plasmalemma. Thus, freeze‐substitution gives new information about structural differences between chemically different types of synapses, which may reflect differences in their transmitter storage, release, and reception. In addition, the AVCN preparation is of general interest in making cell bodies in the mammalian central nervous system available to the various structural and analytical techniques which depend on direct, rapid freezing.
Distribution of nuclear pores and chromatin organization in neurons and glial cells of the rat cerebellar cortex
Authors: Garcia‐Segura L. M. , Lafarga M. , Berciano M. T. , Hernandez P. , Andres M. A. 
Published: January 2005

AbstractNuclear pores were assessed on freeze‐fracture replicas from different neuronal and glial cell types of the rat cerebellar cortex. Nuclear diameter and perimeter were measured on semithin sections, and nuclear surface area and volume were calculated from these data. The proportion of inner nuclear membrane in apposition to condensed chromatin was measured on thin sections. The values of nuclear pore numerical density (number/μm2) were as follows (mean ± S.D.): Purkinje cells, 22 ± 3; Golgi cells 17 ± 3; granule cells, 6 ± 4; stellate and basket cells, 6 ± 1; protoplasmic astrocytes, 11 ± 1; Bergmann glia, 10 ± 1; oligodendrocytes, 6 ± 1. The total number of nuclear pores per nucleus varied from 18,451 ± 2,336 (Purkinje cells) to 621 ± 394 (granule cells) among neurons, and from 1,782 ± 162 (protoplasmic astrocytes) to 402 ± 67 (oligodendrocytes) among glial cells. The number of nuclear pores per unit nuclear volume (number/μm3), a parameter related to nucleocytoplasmic transport capacity, varied from 15 ± 2 in Purkinje cells to 6 ± 4 in granule cells. The proportion of nuclear membrane free of condensed chromatin was significantly (P < 0.01) correlated to pore numerical density and total number of pores per nucleus. Some nuclear pores were associated in clusters of two or more pores. The amount of pore clustering was measured by counting the proportion of pores associated in clusters. This proportion varied among the different cell types from 82% in Purkinje cells to 44% in stellate and basket cells. The amount of pore clustering showed a positive linear correlation to pore numerical density and pore number per nucleus. However, the proportion of pores in clusters was not significantly correlated with the amount of condensed chromatin applied against the inner nuclear membrane.
Glutamic‐acid‐decarboxylase‐ and parvalbumin‐like‐immunoreactive structures in the olfactory bulb of the human adult
Authors: Ohm T. G. , Müller H. , Ulfig N. , Braak E. 
Published: January 2005

AbstractThis study examines the distribution and morphological characteristics of glutamic‐acid‐decarboxylase‐like (GAD)‐ and parvalbumin‐like (PA)‐immunoreactive structures in the olfactory bulb of the human adult.GAD‐immunoreactive somata occurred in the glomerular layer, the external granule cell layer, the more superficial portion of the external plexiform layer, and the internal granule cell layer. The cells were small‐ to mediumsized. Demonstration of lipofuscin pigment revealed the presence of unpigmented as well as pigmented neurons, thus suggesting the existence of two subpopulations of GAD‐positive neurons. GAD‐immunoreactive puncta and/or fibers were mainly seen in the periglomerular region and the internal granule cell layer. All other layers of the bulb, as well as the intrabulbar portion of the anterior olfactory nucleus, displayed considerably less of these puncta and/or fibers. The olfactory nerve layer remained practically clear of immunoreactive material.PA‐immunoreactive somata occurred in the glomerular layer and both the external and internal granule cell layer. Only a small number of immunoreactive nerve cells were encountered within the white matter or the olfactory tract. Most PA‐positive neurons displayed characteristics of short axon cells whereas a few others resembled van Gehuchten cells. All of the PA‐immunoreactive neurons were devoid of lipofuscin pigment. Immunoreactive puncta and fibers were present in all layers though predominating in the periglomerular region, the olfactory nerve layer, and the internal granule cell layer. The intrabulbar portions of the anterior olfactory nucleus did not show any immunoreactive structures.