bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of two morphologically distinct subsets of serotoninergic axons in the cerebral cortex of the marmoset
Authors: Hornung Jean‐Pierre , Fritschy Jean‐Marc , Törk Istvan 
Published: January 2005

AbstractThe serotoninergic innervation of the marmoset (New World monkey, Callithrix jacchus) cerebral cortex has been analyzed by using immunocytochemistry. The use of a sensitive monoclonal antibody against serotonin allowed the visualization of the fine morphology of individual axons. Two types of terminal axons were demonstrated: one has sparse, small, ovoid varicosities (dia. less than 1 μm), and the other has large, spheroidal varicosities (up to 5 μm in dia.), which are more densely clustered. The first type of axon is distributed through all cortical layers, with a characteristic laminar distribution that varies from area to area. The second type of axons was distributed sparsely in all regions but was markedly denser in the frontal and anterior parietal lobes, and in the hippocampal formation.Axons with large varicosities typically surrounded certain cell bodies and proximal dendrites, forming pericellular arrays, or baskets. These morphological specializations were most frequent in the frontal and anterior parietal cortex, where they were found around stellate and horizontal cells in layer I and around stellate and bipolar cells in layer II and III. Similar baskets were also found in the hippocampal formation, mainly along the border between the hilus and the granule cell layer of the dentate gyrus, across the CA4 field, and at each side of the pyramidal cell layer of the CA3 regions. The distribution and cellular morphology of the cell surrounded by the 5‐HT basket fibres were suggestive of a subpopulation of interneurons, possibly GABAergic and/or peptidergic. In agreement with previous reports on the innervation of the cerebral cortex of other mammalian species, the marmoset cerebral cortex is innervated by two separate subsystems of serotoninergic axons. One of these may have a strong and specific influence on the cortical inhibitory circuitry, via relay through cortical interneurons.
Organization of the spinal cord in four species of elasmobranch fish: Cytoarchitecture and distribution of serotonin and selected neuropeptides
Authors: Cameron Adrian A. , Plenderleith Mark B. , Snow Peter J. 
Published: January 2005

AbstractAn analysis of Nissl stained sections of the spinal cord taken from four species of elasmobranch showed that seven distinct cytoarchitectonic laminae are present. These laminae are compared with laminae described previously in the spinal cord of other vertebrates.The distribution of immunoreactivity to serotonin, substance P, somatostatin, calcitonin gene‐related peptide, neuropeptide Y, and bombesin was determined in the brown stingray (Dasyatis fluviorum), the eagle ray (Aetobatis narinari), the shovelnose ray (Rhinobatis battilum), and the black‐tip shark (Carcharhinus melanopterus). In all species, dense immunoreactivity to most substances tested was found in the outer part of the substantia gelatinosa. Many fibres and varicosities immunoreactive to substance P, calcitonin gene‐related peptide, and bombesin were found in this region and smaller numbers of fibres were found in the nucleus proprius. Immunoreactivity to somatostatin consisted of coarse fibre bundles that entered the dorsal horn at the nucleus proprius and radiated dorsally to the substantia gelatinosa. Axons and varicosities immunoreactive to serotonin and neuropeptide Y were found in all regions of the dorsal horn but were concentrated in the outer part of the substantia gelatinosa. The distribution of immunoreactivity to met‐enkephalin in the shovelnose ray was concentrated in the lateral third of the substantia gelatinosa and to a lesser extent in the nucleus proprius.The distribution of these substances is compared with that described in other vertebrates. Although the sensory information reaching the elasmobranch spinal cord is limited, compared with that of mammalian species, the distribution of these neuroactive factors in the dorsal horn of the two groups is strikingly similar.
Distribution of motor neurons into anatomical groups in the grasshopper metathoracic ganglion
Authors: Siegler Melody V. S. , Pousman Cynthia A. 
Published: January 2005

AbstractMotor neurons of the main muscles of the hind legs and the hind wings of the grasshopper are distributed into eight anatomical groups within each half of a bilaterally symmetrical segmental ganglion. A group contains 5 to 24 identified motor neurons, accounting for 164 (82 pairs) of the some 200 motor neurons within the population. The motor neurons within a given group may contribute axons to more than one of the lateral nerves, and conversely each lateral nerve contains axons arising from motor neurons in separate groups. Groups may include synergistic and antagonistic motor neurons as well as those that have unrelated functions. The motor neurons of a given muscle may occur together in a single group, or separately in two or more groups. The description of groups provides a way of classifying neurons to simplify and organize the large amount of data on the structure and function of individually identified neurons within the ganglion. The organization of the motor neurons into groups may reflect their developmental origin from individual neuroblasts, and the detailed information about the pattern of groups in the adult thus allows specific predictions to be made about the composition of neurons within neuronal lineages.
Effect of temperature on long‐term survival of anucleate giant axons in crayfish and goldfish
Authors: Blundon Jay A. , Sheller Rebecca A. , Moehlenbruck Jeffrey W. , Bittner George D. 
Published: January 2005

AbstractThe effect of temperature on the electrophysiology and morphology of anucleate axons was examined following severance of crayfish medial giant axons and goldfish Mauthner axons from their respective cell bodies. Although anucleate segments of each giant axon exhibited long‐term survival for weeks to months at 5–25°C in crayfish and 10–30°C in goldfish, the two axons differed in their survival characteristics. All measures of long‐term survival in crayfish medial giant axons were independent of animal holding temperature, whereas all measures in Mauthner axons were dependent on holding temperature. Medial giant axons survived for at least 90 days in crayfish maintained at 5–25°C in this and previous studies. Mauthner axons survived for over 5 months in goldfish maintained at 10°C but survived for 1 month at 30°C. Postoperative time had different effects on many single measures of long‐term survival (axonal diameter, amplitude of action or resting potentials) in medial giant axons compared to Mauthner axons. For example, resting and action potentials in crayfish medial giant axons remained remarkably constant at all holding temperatures for 0–90 postoperative days. In contrast, resting and action potentials in goldfish Mauthner axons declined abruptly in the first 10–20 postoperative days followed by a slower decline at each holding temperature. We suggest that the mechanism of long‐term survival is not necessarily the same in all anucleate axons.
Proctolin in the innervation of the locust mandibular closer muscle modulates contractions through the elevation of inositol trisphosphate
Authors: Baines Richard A. , Lange Angela B. , Downer Roger G. H. 
Published: January 2005

AbstractExtracts of the locust (Locusta migratoria) mandibular closer muscle separated on reverse‐phase HPLC and tested for bio‐activity on the locust oviduct contain a bio‐active substance that coelutes with authentic proctolin. Furthermore, the effect on oviduct contractions of this compound is indistinguishable from that of authentic proctolin. Antiserum to proctolin stains numerous axons with beaded endings that run along the fibres of the closer muscles and, in addition, the antiserum stains a number of cell bodies in the suboesophageal ganglion, some of which have axons in the mandibular nerve that innervates the mandibular musculature.The function of proctolin appears to be modulatory as its presence significantly increases the amplitude of neurally evoked contractions of the closer muscle. This effect can be mimicked by the addition of inositol 1,4,5,‐trisphosphate (IP3) to preparations in which the muscles have been permeabilized with dimethyl sulfoxide. The involvement of this second messenger is further implicated as we also show that proctolin produces a large, significant increase in the IP3 content of homogenized muscle.
Primary afferent origin of substance P‐containing axons in the superficial dorsal horn of the rat spinal cord: Depletion, regeneration and replenishment of presumed nociceptive central terminals
Authors: Knyihár‐Csillik Elizabeth , Török Ágotha , Csillik Bert 
Published: January 2005

AbstractSubstance P‐like immunoreactivity (SPLI) was localized in the superficial spinal dorsal horn of the rat by means of light and electron microscopic immunocytochemical techniques. Serial immunocytochemical sections were subjected to densitometric measurements with an electronic Image Analyser, and with aid of a computer program, a two‐dimensional reconstruction of the fine neuroanatomical structure of the SPLI‐active regions of the lumbosacral upper superficial spinal dorsal horn was obtained. SPLI activity in the superficial dorsal horn outlines four well‐marked and distinctly differing regions, called, in the mediolateral sequence, areas A, B, C, and D, plus Cajal's noyeau interstitiel (“lateral spinal nucleus” = “nucleus of the dorsolateral fascicle,” L). Lumbosacral dorsal rhizotomy results in an almost complete depletion of SPLI from ipsilateral areas A, B, C, and D; it induces decreased SPLI in the area of the lateral spinal nucleus (L), ipsi‐ or contralaterally in an alternating fashion. Transection of the segmentally related, ipsilateral peripheral nerve induces a marked depletion of SPLI from areas A, B, and C but only a slight decrease in area D and virtually none in the area of L. Whereas a simple crush of the peripheral nerve (axocompression) induces only a slight depletion of SPLI, if any, semiautomatic densitometric analysis of serial immunocytochemical sections proves that a controlled crush injury (axocontusion) results in depletion of SPLI from the upper dorsal horn, similar to transection of the peripheral nerve. Following regeneration of the ipsilateral, segmentally related peripheral nerve, the original immunocytochemical structure of the superficial dorsal horn is re‐established by SPLI‐positive axonal sprouts originating from previously damaged dorsal root axons.
Comparative study of histamine immunoreactivity in nervous systems of Aplysia and Pleurobranchaea
Authors: Soinila Seppo , Mpitsos George J. , Panula Pertti 
Published: January 2005

AbstractThe distribution of histamine in the nervous system of the marine molluscs Aplysia californica and Pleurobranchaea californica was studied by using a newly available immunohistochemical localization technique and specific antiserum against histamine‐protein conjugate. We examined several sets of complete histological sections through the major ganglia of both animals, as well as all nerve roots of the buccal and cerebral ganglia and the corresponding target tissues. The results indicate that histamine is present in several neurons and/or nerve fibers of all major ganglia. An especially dense histamine fiber network in the buccal ganglion of both species suggests a major role for histamine in regulation of buccal‐oral behaviors. Histamine was also observed in several identified nerve roots of the buccal and cerebral ganglia, as well as in the corresponding target tissues. Its localization in the Aplysia radular sac and in the statocyst neurons of both species suggest a role for histamine in sensory functions. Our study revealed many previously unknown histamine cells or cell clusters, some of which may be identifiable by electrophysiological methods. The findings also point to possible reinterpretation of previous findings, indicating that histamine may be a cotransmitter in identified cells, whereas the methodology itself suggests that special precautions must be taken to avoid spurious interpretations of specificity. As has now been observed in studies of serotonergic immunohistochemistry and in our own findings on VIP, histamine terminals were observed to lie in close contact with somata and axon hillocks, all of which suggest that axo‐somatic connections in molluscs may be more prevalent than previously considered.
Peripheral and central terminations of hypoglossal afferents innervating lingual tactile mechanoreceptor complexes in Fringillidae
Authors: Wild J. Martin 
Published: January 2005

AbstractInjections of cholera toxin B subunit conjugated to horseradish peroxidase (CTB‐HRP) were made into the lingual branch of the hypoglossal nerve in four species of finch in order to identify the innervation of the mechanoreceptors of the dermal papillae of the tongue, and simultaneously to determine the pattern of central projections of lingual hypoglossal afferents. The results showed that hypoglossal fibers innervate all the Herbst corpuscles and terminal cell receptors of the elaborately organized papillae of the dorsum of the tongue, of the shorter papillae in the ventral tongue, and the loose collection of Herbst corpuscles in the subpapillary region. Labelled fibers were also observed in the intralingual glands, in the intrinsic tongue muscles, and in the posterodorsal epithelium where they formed budlike structures.Retrogradely labelled cell bodies were located in the jugular ganglion and their central processes ascended and descended throughout the brainstem within the descending trigeminal tract (TTD). Terminal fields were observed within the dorsolateral part of the nucleus caudalis of TTD, predominantly ipsilaterally, and within the medial part of the dorsal horn of the first 4–6 cervical segments bilaterally. There were dense patches of termination over a dorsolateral subnucleus of the interpolated nucleus of TTD, and within two regions of the principal sensory trigeminal nucleus: a large one laterally and a small one medially.Terminal fields were also observed within the nucleus ventralis lateralis anterior of the rostral solitary complex, and within adjacent nuclei, which are probably equivalent to the dorsal sensory nuclei of the facial and glossopharyngeal nerves of other avian species.The results are interpreted in the light of the role of the tongue in species‐specific patterns of feeding in finches, and the possible requirement for the central integration of touch and taste.
Fine structure of the lateral mammillary projection to the dorsal tegmental nucleus of gudden in the rat
Authors: Hayakawa Tetsu , Zyo Katuya 
Published: January 2005

AbstractThe synaptic organization of projections from the lateral mammillary neurons within the dorsal tegmental nucleus of Gudden is studied in the rat with the aid of anterograde transport of horseradish peroxidase conjugated with wheat germ agglutinin (WGA‐HRP) and visualized with tetramethylbenzidine. The dorsal tegmental nucleus consists of the pars ventralis (TDV) and the pars dorsalis (TDD). The normal neuropil of the dorsal tegmental nucleus contains three classes of axodendritic terminals, that is, terminals containing round, flat, and pleomorphic vesicles. They make up 44%, 5%, and 51%, respectively, of all axodendritic terminals in the TDV, and 62%, 1%, and 37% in the TDD.Injection of WGA‐HRP into the lateral mammillary nucleus permits ultrastructural recognition of many anterograde labeled terminals within both the TDV and TDD. In the TDV, 81% of the labeled terminals contain round synaptic vesicles and make asymmetric synaptic contacts. A few of the labeled terminals contain pleomorphic vesicles and make symmetric synaptic contacts. More than 50% of the labeled terminals contact intermediate dendrites (1–2 μm diameter). In the TDD, almost all labeled terminals are small, contain round vesicles, and make asymmetric synaptic contacts. These terminals mainly contact intermediate as well as distal (less than 1 μm diameter) dendrites. There are only a few labeled terminals with pleomorphic vesicles and no terminals with flat vesicles. The termination pattern of the lateral mammillary neurons in the TDV is similar to that in the TDD. Anterograde labeled axon terminals often contact retrograde labeled dendrites in the TDV. No reciprocal connections are present in the TDD. These results suggest that the TDV and the TDD receive mainly excitatory and a few inhibitory inputs from the lateral mammillary nucleus. The TDV neurons also have direct reciprocal connections with the lateral mammillary neurons.
Immunohistochemical study of the serotoninergic innervation of the basal ganglia in the squirrel monkey
Authors: Lavoie Brigitte , Parent André 
Published: January 2005

AbstractA specific antibody raised against 5‐hydroxytryptamine (5‐HT) conjugated to bovine serum albumin was used to study the serotoninergic innervation of the basal ganglia in the squirrel monkey (Saimiri sciureus). At midbrain level, numerous fine 5‐HT‐immunoreactive axons were seen to arise from the immunopositive neurons of the dorsal raphe nucleus and less abundantly from those of the nucleus centralis superior. The bulk of these axons formed a rather loosely arranged bundle that arched ventrorostrally through the central portion of the midbrain tegmentum and ascended toward the ventral tegmental area. Several fascicles detached themselves from this bundle to reach the substantia nigra where they arborized into a multitude of heterogeneously distributed 5‐HT terminals. The 5‐HT innervation was particularly dense in the pars reticulata but much less so in the pars compacta of the substantia nigra. More rostrally other 5‐HT fibers swept dorsolaterally and formed a remarkably dense network of varicose fibers within the subthalamic nucleus. A multitude of 5‐HT axons continued their ascending course within the lateral hypothalamic area, and many of them swept laterally to invade the lenticular nucleus. At pallidal levels, the 5‐HT axons arborized much less profusely in the external segment than in the internal segment, which contained numerous 5‐HT varicose fibers and terminals arranged in a typical bandlike pattern. At striatal levels, the 5‐HT terminals were particularly abundant in the ventral striatum, including the nucleus accumbens and deep layers of the olfactory tubercle. They also abounded in the ventrolateral region of the putamen and the ventromedial aspect of the caudate nucleus. Overall, the number of 5‐HT fibers and terminals decreased progressively along the rostrocaudal axis of the striatum and several large and elongated zones rather devoid of 5‐HT immunoreactivity were visualized, particularly in the caudate nucleus and the dorsal putamen. These zones of poor 5‐HT immunoreactivity were in register with similar areas devoid of tyrosine hydroxylase immunoreactivity as seen on contiguous sections. These findings reveal that all the core structures of the basal ganglia in primates receive a significant serotoninergic input, but that the densities and patterns of innervation vary markedly from one structure to the other.
Thalamic projections to sensorimotor cortex in the macaque monkey: Use of multiple retrograde fluorescent tracers
Authors: Darian‐Smith Corinna , Darian‐Smith Ian , Cheema Surindar S. 
Published: January 2005

AbstractWe used several fluorescent dyes (Fast Blue, Diamidino Yellow, Rhodamine Latex Microspheres, Evans Blue, and Fluoro‐Gold) in each of eight macaques, to examine the patterns of thalamic input to the sensorimotor cortex of macaques 12 months or older. Inputs to different zones of motor, premotor, and postarcuate cortex, supplementary motor area, and areas 3b/1 and 2/5 in the postcentral cortex, were examined. Coincident labeling of thalamocortical neuron populations with different dyes (1) increased the precision with which their soma distributions could be related within thalamic space, and (2) enabled the detection by double labeling, of individual thalamic neurons that were common to the thalamic soma distributions projecting to separate, dye‐injected cortical zones.Double‐labeled thalamic neurons projecting to sensorimotor cortex were rarely seen in mature macaques, even when the injection sites were only 1–1.5 mm apart, implying that their terminal arborizations were quite restricted horizontally. By contrast, separate neuron populations in each thalamic nucleus with input to sensorimotor cortex projected to more than one cytoarchitecturally distinct cortical area. In ventral posterior lateral (oral) (VPLo), for example, separate populations of cells sent axons to precentral medial, and lateral area 4, medial premotor, and postarcuate cortex, as well as to supplementary motor area.Extensive convergence of thalamic input even to the smallest zones of dye uptake in the cortex (≈0.5 mm3) characterized the sensorimotor cortex. The complex forms of these projection territories were explored using 3‐dimensional reconstructions from coronal maps. These projection territories, while highly ordered, were not contained by the cytoarchitectonic boundaries of individual thalamic nuclei. Their organization suggests that the integration of the diverse information from spinal cord, cerebellum, and basal ganglia that is needed in the execution of complex sensorimotor tasks begins in the thalamus.