bluuebunny/crossref_metadata_2025_split huggingface dataset:
The motor neurons innervating the direct flight muscles of Drosophila melanogaster are morphologically specialized
Authors: Trimarchi James R. , Schneiderman Anne M. 
Published: January 2005

AbstractThe anatomy of the motor neurons innervating six direct flight muscles in Drosophila melanogaster has been investigated by using a horseradish peroxidase backfilling technique. The somata of these motor neurons are arranged in two distinct clusters ipsilateral to the muscle they innervate. One cluster of cell bodies is located in the ventrolateral region between the prothoracic neuromere and the mesothoracic leg‐related neuropil and the other is situated dorsally and posteriorly to the mesothoracic leg‐related neuropil. Axons from somata in the ventrolateral cluster run in the anterior dorsal mesothoracic nerve, while axons from somata in the other cluster run in the mesothoracic accessory nerve. This distribution of somata and axons is discussed in the light of the morphological similarity and proximity of these functionally related muscles.On the basis of the branching patterns of their neurites, direct flight muscle motor neurons can be classified as stubbly, fibrous or tufted. The terminal arborizations of the motor neurons over the direct flight muscles are also morphologically specialized. Both the central and the peripheral morphological specializations of the direct flight muscle motor neurons correlate with the activity patterns exhibited by their associated muscles during flight and courtship song. © Wiley‐Liss, Inc.
Immunohistochemical detection of calcium/calmodulin‐dependent protein kinase II in the spinal cord of the rat and monkey with special reference to the corticospinal tract
Authors: Terashima Toshio , Ochiishi Tomoyo , Yamauchi Takashi 
Published: January 2005

AbstractCalcium/ calmodulin‐dependent protein kinase II is a prominent enzyme in the mammalian brain that phosphorylates a variety of substrate proteins. In the present study, monoclonal antibodies that specifically recognize either the α or the β isoforms of this enzyme were used to determine the distribution of these isoforms within the rat and monkey spinal cord. In the rat, the corticospinal tract consists of two components: the dorsal corticospinal tract, which occupies the ventralmost aspect of the dorsal funiculus; and the ventral corticospinal tract, which occupies an area adjacent to the ventral median fissure. Both dorsal and ventral corticospinal tract fibers were strongly immunopositive for the α‐antibody. Unilateral ablation of the sensorimotor cortex of the rat eliminated the α‐immunoreactive staining in the contralateral dorsal corticospinal tract. The neuropil in the superficial laminae of the dorsal horn (Rexed's laminae I and II) was densely stained with the α‐antibody, whereas the neuropil in laminae IV‐X was immunonegative. Dense α‐immunopositive neurons were also distributed in the head of the dorsal horn (laminae I‐IV). In contrast to the strong α‐immunoreactivity seen in the dorsal corticospinal tract fibers, only very weak β‐immunoreactivity was observed in this tract. Moderate β‐immunoreactive products were distributed homogenously throughout the neuropil of the gray matter, although the neuropil of the superficial laminae of the dorsal horn (laminae I and II) was stained more strongly than the other regions of the gray matter (laminae III‐X). Neuronal components in all laminae were immunopositive for the β‐antibody. Thus, motoneurons in the ventral horn, which were immunonegative for the α‐antibody, were immunopositive for the β‐antibody. This selective distribution pattern of immunoreactivity of α‐ and β‐antibodies in the rat was also present in the monkey spinal cord, although the α‐immunopositive corticospinal tract fibers in the monkey descended in the lateral funiculus as the lateral corticospinal tract instead of passing through the dorsal funiculus, as is the case in the rat. The differential distribution of immunoreactivity in the spinal cord suggests that these two isoforms of calcium/ calmodulin‐dependent protein kinase II may have different functional roles in the spinal cord. © Wiley‐Liss, Inc.
Morphological assessment of grafted rat and mouse cortical neurons: A light and electron microscopic study
Authors: Lübke Joachim , Wood Matthew J. A. , Clarke Deborah J. 
Published: January 2005

AbstractThe morphology of cortical neurons grafted into (or near) the rat striatum was studied by means of intracellular Lucifer yellow injections in fixed slices. Rat donor syngeneic cortical tissue (from postnatal day 1 old rats; AO strain) as well as mouse donor xenogeneic cortical tissue (prenatal day 19; C3H/HE strain) were grafted as solid pieces into 8–12 week‐old rats (AO strain). Recipients of mouse xenografts were immunosuppressed with a monoclonal antibody against the interleukin‐2 receptor. After perfusion and sectioning of the graft‐containing areas, individual slices were incubated in the DNA stain 4.6‐diamidino‐2‐phenylindole (DAPI) to visualize the cell nuclei. Grafts could be easily identified by a surrounding rim of astrocytes which outline the border between grafted and host tissue. Grafted cortical neurons were intracellularly filled with Lucifer yellow, DAB‐photoconverted, and further processed for light and electron microscopy.In general, no cortical lamination could be observed in the grafted rat and mouse cortical tissue, but neurons were loosely packed throughout the graft. Two major cell types could be identified in all grafts investigated so far. The majority resembled those described as spiny neurons (85%), which could be further classified into pyramid‐like, spiny stellate‐like or fusiform spiny neurons, with somata ranging between 15 and 25 μm in diameter. The remaining 15% resembled non‐spiny neurons with either a multipolar basket‐like or fusiform morphology. Dendrites of spiny and non‐spiny neurons, which could extend to distances up to 400 μm, were never seen to cross the astrocytic border, but some main axon and axonal collaterals of spiny neurons were found to leave the graft. On the basis of light microscopic observations no difference was found between mouse and rat grafted cortical neurons. The results of this study show that grafted cortical neurons retain some of the characteristic features of neurons in the intact adult cerebral cortex, although there appears to be a greater preponderance of spiny neurons in grafted tissue. This may reflect an immaturity of the grafted tissue or a response to the striatal environment.
Peptidergic neurons in the snail Helix pomatia: Distribution of neurons in the central and peripheral nervous systems that react with an Antibody raised to the insect neuropeptide, leucokinin I
Authors: Elekes K. , Hernádi L. , Muren J. E. , Nässel D. R. 
Published: January 2005

AbstractIn this study, antiserum raised against an insect myotropic peptide, leucokinin I (DPAFNSWGamide), was: used for mapping leucokinin‐like immunoreactive (LK‐LI) neurons in the gastropod mollusc, Helix pomatia. Immunocytochemistry performed on both whole‐mounts and cryostat sections demonstrated LK‐LI neurons in all ganglia of the central nervous system (CNS), except the visceral ganglion. Altogether about 700 immunolabelled neurons have been found, with nearly one‐half (46%) in the cerebral ganglia. A large proportion of the LK‐LI neurons have small cell bodies and are likely to be interneurons. The most prominent LK‐LI cell group is represented by the entire neuron population of the mesocerebri, which is the major source of a thick fiber bundle system, encircling and innervating the whole CNS. One single LK‐LI giant neuron was found, which is located in the left pedal ganglion and is termed GLPdLKC (giant left pedal leucokinin immunoreactive cell). This cell has not been identified previously. The ganglion neuropils are heavily innervated by varicose LK‐LI fiber arborizations. Some integrative centers, such as the medullary neuropil of the procerebri, reveal an extreme density of LK‐LI innervation. All major peripheral nerves contain a large number of LK‐LI axons, and LK‐LI innervation is found in the musculature of different peripheral organs (buccal mass, lip, tentacles, oviduct, intestine). Among the peripheral organs investigated, the intestine contains a rich varicose LK‐LI network, composed of both intrinsic and extrinsic elements. Radioimmunoassay (RIA) demonstrates a very high content of LK‐LI material in Helix ganglion extracts (about 50 pmol/CNS). This is the first report on the occurrence of a substance resembling the myotropic neuropeptide leucokinin I in a phylum outside arthropods. Based on our immunocytochemical observations, a role for leucokinin‐like peptides in both central and peripheral regulatory processes in Helix is suggested. According to double‐labelling experiments, only a small number of the LK‐LI neurons are labelled with an antibody to the vertebrate tachykinin substance P.
Nerve growth factor‐like immunoreactive profiles in the primate basal forebrain and hippocampal formation
Authors: Mufson Elliott J. , Conner James M. , Varon Silvio , Kordower Jeffrey H. 
Published: January 2005

AbstractThe distribution of nerve growth factor (NGF), the prototypic neurotrophin, within the basal forebrain and hippocampal formation of young adult monkeys and aged humans was characterized with and affinity purified polyclonal β‐NGF antibody raised against mouse β‐NGF. In the basal forebrain of both primates, a granular NGF‐like immunoreactive (ir) reaction product was observed within neurons of the medial septum, nucleus of the diagonal band, and nucleus basalis of Meynert. NGF‐like immunoreactivity exclusively colocalized within p75 NGF receptor (NGFR) containing basal forebrain neurons. The intensity of NGF immunolabeling varied between cell bodies. Many NGF‐ir perikarya were highly immunoreactive. In other basal forebrain neurons, NGF‐like immunoreactivity was either undetectable or minimally expressed. In the hippocampus of both species, NGF‐like immunoreactivity was mainly localized within the hilus of the dentate gyrus and within CA3 and CA2 hippocampal subfields. A marked diminution in NGF‐like staining was seen in CA1. Within the hippocampal formation, NGF‐like immunoreactivity was heaviest within the neuropil of stratum radiatum, intermediate in stratum oriens, and lightest in stratum pyramidal. NGF‐like immunoreactivity was not found within the granule or pyramidal cells of the dentate gyrus and hippocampal formation, respectively. These findings demonstratre the presence of an NGF‐like antigen in association with monkey and human magnocellular basal forebrain neurons and within their hippocampal target sites. This lends support to the hypothesis that NGF is internalized from sources located within target regions of the primate cholinergic basal forebrain neurons and is retrogradely transported to these cell bodies where the NGF trophic effect likely occurs.
Morphogenesis of catecholaminergic interneurons in the frog spinal cord
Authors: Heathcote R. David , Chen Aileen 
Published: January 2005

AbstractDuring embryonic and larval development of the frog Xenopus laevis, a bilateral population of cerebrospinal fluid‐contacting neurons matures in the ventral spinal cord. These cells are catecholaminergic and form a dispersed or nonrandom pattern of spacing within each of their spinal cord columns. In order to test the mechanisms underlying pattern formation of these neurons, it is first necessary to understand their normal morphogenesis. Morphogenetic changes were examined by using immunocytochemistry for tyrosine hydroxylase as a cell marker. Immunoreactivity in spinal cord cells was detected as early as 1.4 days (stage 28) of embryonic development. Subsequently, these cells underwent changes in shape, and rapid, regressive changes in cell size. The population emerges gradually during development, but the major characteristic of nonrandom spacing, their dispersion from other catecholaminergic cells, is apparent at early stages of differentiation. Increases in cell density occur over an extended period of time and can be divided into an initial phase of large, rapid changes and a subsequent plateau phase of gradual changes. The two longitudinal columns of catecholaminergic cells that are characteristic of older animals become apparent just before hatching, when density increases until cells on both sides of the midline are present in the same region. Although the dispersed pattern exists within each column, cross‐correlation analysis shows that there is a random relationship between cells in opposite columns. During larval development, the catecholaminergic cell domain expands in both a rostral and caudal direction. The morphogenetic changes of the catecholminergic cell population begin to show how the cells become partitioned within the floor plate region of the spinal cord. © 1994 Wiley‐Liss, Inc.
Age and damage induced changes in amyloid protein precursor immunohistochemistry in the rat brain
Authors: Beeson James G. , Shelton Earl R. , Chan Hardy W. , Gage Fred H. 
Published: January 2005

AbstractAlzheimer's disease (AD) is characterized by the extensive deposition of the 42‐amino‐acid β‐amyloid or A4 protein in neuritic plaques and neurofibrillary tangles within the brain. This protein is liberated from the much larger amyloid protein precursor (APP). Multiple species of APP have been proposed, including several forms that contain a 56 amino acid insert sequence analogous to the Kunitz protease inhibitors. Although expression of APP mRNA is reportedly altered in AD brain and various roles for APP have been proposed, the pathogenesis of amyloid deposition and AD remains unclear. AD is also characterized by specific memory impairments associated with decreased cholinergic activity. While aging rats do not develop mature amyloid pathology, behaviorally impaired aged rats demonstrate an analogous cholinergic decline. In this study, we examined behaviorally characterized aged rats and normal young controls for changes in APP immunohistochemistry by using anti‐APP antibodies, which detect N‐ or C‐terminal regions and which distinguish APP species with or without the Kunitz protease inhibitor domain. The results show specific age‐ and behavior‐related changes in cortical APP immunoreactivity as well as limited numbers of APP immunoreactive deposits in the aged rats. Additionally, we found that lesions of the fimbria‐fornix pathway, which in part mimic the memory impairments and loss of cholinergic activity seen in AD, result in the marked accumulation of APP immunoreactive material in the region of cholinergic fiber degeneration in the hippocampus. These findings are discussed in relation to the pathogenesis of AD in humans. © 1994 Wiley‐Liss, Inc.
Efferent connections from the lateral hypothalamic region and the lateral preoptic area to the hypothalamic paraventricular nucleus of the rat
Authors: Larsen Philip J. , Hay‐Schmidt Anders , Mikkelsen Jens D. 
Published: January 2005

AbstractThe lateral preoptic and lateral hypothalamic regions contain the majority of the cell groups embedded in the fibre trajectories of the medial forebrain bundle on its course through the hypothalamus. Recent studies have extended considerably the parcellation of the lateral hypothalamic region, and, therefore, the need to emphasize new insights into the anatomical organisation of projections from the neurons of the lateral hypothalamic region. In the present study we describe the anatomical organisation of efferent projections from the lateral preoptic and lateral hypothalamic regions to the hypothalamic paraventricular nucleus (PVN) on the basis of retrograde‐ and anterograde‐tracing techniques. Iontophoretic injections of the retrograde tracer, cholera toxin subunit B, into the PVN revealed that most hypothalamic nuclei project to the PVN. Within the lateral hypothalamic region, retrogradely labelled cells were concentrated in the intermediate hypothalamic area, the lateral hypothalamic area, and the perifornical nucleus, whereas fewer retrogradely labelled cells were found in the lateral preoptic area.To determine the distribution of terminating fibres in subnuclei of the heterogeneous PVN, iontophoretic injections of the anterograde tracer Phaseolus vulgaris‐leucoagglutinin were delivered into distinct areas of the lateral hypothalamic region. Neurons of the intermediate hypothalamic area projected mainly to the PVN subnuclei, which contained parvicellular neuroendocrine cells. In contrast, neurons of the rostral and tuberal parts of the lateral hypothalamic area and the perifornical nucleus projected to the PVN subnuclei, which contained parvicellular neurons that send descending projections to preganglionic cell groups in the medulla and spinal cord. The perifornical nucleus was the only area within the lateral hypothalamic region that consistently innervated magnocellular perikarya of the PVN. Finally, all areas of the lateral hypothalamic region contributed substantially to fibres terminating in the perinuclear shell of the PVN. These results demonstrate that anatomically distinct areas of the lateral hypothalamic region have distinct projections to subnuclei of the PVN and further substantiate the view that the lateral hypothalamic region as well as the PVN constitute anatomically and functionally heterogeneous structures. © 1994 Wiley‐Liss, Inc.
Neural network controlling feeding in Lymnaea stagnalis: Immunocytochemical localization of myomodulin, small cardioactive peptide, buccalin, and FMRFamide‐ related peptides
Authors: Santama Niovi , Brierley Matthew , Burke Julian F. , Benjamin Paul R. 
Published: January 2005

AbstractThis paper investigates the distribution of four classes of neuropeptides, myomodulin, small cardioactive peptide (SCP), buccalin, and FMRFamide, in central neurons forming the network that underlies feeding behavior in the snail Lymnaea stagnalis. Intracellular dye‐marking and immunocytochemical analysis, using antisera to the different classes of peptides, were applied to identified neurons of all three levels of the hierarchy of the circuitry: modulatory interneurons (cerebral giant cells, CGC; slow oscillator, SO), central pattern generator (CPG) interneurons (N1, N2, N3), motoneurons (B1–B10), and their peripheral target organs. Myomodulin immunoreactivity was detected in the CGC interneurons, in the SO, and in ventral N2‐type CPG interneurons. Several large buccal motoneurons, the paired B1, B2, B3, B7, and neurons located in the dorsal posterior area (putative B4 cluster types) were also myomodulin immunoreactive. Target organs of buccal motoneurons, the buccal mass, salivary glands, and oesophagus contained myomodulin‐immunopositive fibers. SCP appeared in N2‐type interneurons and was found colocalized with myomodulin in the B1 and B2 motoneurons. SCP‐containing neurons in the B4 cluster area were also detected. The buccal mass and salivary glands exhibited SCP‐immunoreactive fibers. Buccalin immunoreactivity was scarce in the buccal ganglia and was identified only in N1‐type interneurons and three pairs of dorsal posterior neurons. In the periphery, immunoreactive fibers were localized in the oesophagus only. None of the buccal neuronal types examined revealed immunoreactivity to SEQPDVDDYLRDVVLQSEEPLY (“SEEPLY”), a peptide encoded in the FMRFamide precursor protein of Lymnaea. SEEPLY immunoreactivity was confined to a pair of novel ventral neurons with projections to the laterobuccal nerve innervating the buccal mass. Immunoreactive fibers were also traced in this organ. © 1994 Wiley‐Liss, Inc.
A study of SMI 32‐stained pyramidal cells, parvalbumin‐immunoreactive chandelier cells, and presumptive thalamocortical axons in the human temproal neocortex
Authors: del Río María R. , DeFelipe Javier 
Published: January 2005

AbstractImmunocytochemical studies in the primate neocortex have shown that particular populations of pyramidal cells can be identified by antibody SMI 32 that recognizes a nonphosphorylated epitope of neurofilament protein, while chandelier cells (a powerful type of cortical inhibitory interneuron) and presumptive thalamocortical axons can be identified by antibodies directed against the calcium‐binding protein parvalbumin (PV). We used these antibodies in correlative light and electron microscopic immunocytochemical studies to analyze certain aspects of the synaptic circuitry of human temporal neocortex. In sections cut in the tangential plane, many PV‐immunoreactive chandelier cell axon terminals and apical dendrites of SMI 32‐stained pyramidal cells were distributed in small clusters. Combination of immunocytochemistry for PV and SMI 32 revealed four subpopulations of pyramidal cells with regard to the immunocytochemical staining by SMI 32 and the innervation of their axon initial segments by PV‐positive or ‐negative chandelier cell axon terminals, but there were differences in the concentration and proportion of these subpopulations by layers. Furthermore, we present electron microscopic evidence suggesting that the characteristic layer III dense band of PV‐immunoreactive puncta is made up mainly of presumptive thalamocortical axon terminals. Besides, coincidence was found between the dense PV‐immunoreactive band and the dendritic plexus formed by the SMI 32‐stained pyramidal cells in the lower half of layer III, which leads us to think that they are probably a major target of PV‐immunoreactive thalamic terminations. © 1994 Wiley‐Liss, Inc.
Distribution of input synapses from processes exhibiting GABA‐ or glutamate‐like immunoreactivity onto terminals of prosternal filiform afferents in the locust
Authors: Watson A. H. D. , Pflüger H.‐J. 
Published: January 2005

AbstractThe locust prosternum carries a population of long filiform hairs that are very sensitive to air currents. The sensory afferent neurons that innervate the hairs make strong monosynaptic connections with an identified intersegmental interneuron (A4I1) which is known to contact motor neurons that supply muscles controlling wing angle during flight. In order discover how the synapse between the afferents and interneuron A4I1 might be modulated, the afferents were labelled intracellularly by backfilling with horseradish peroxidase to reveal their central terminals which lie in the prothoracic ganglion. A postembedding immunogold method was used to make a quantitative assessment of the prevalence of immunoreactivity for GABA and glutamate in processes presynaptic to the afferent terminals. In one afferent neuron, where 77 synapses were examined, 40 (52%) of the presynaptic processes were immunoreactive for GABA. When adjacent sections through the same terminal branches were labelled with the two antibodies, it was demonstrated that GABA‐ and glutamate‐like immunoreactivity was present in different populations of presynaptic processes. A series of 110 ultrathin sections was cut through one set of afferent terminal branches and alternate grids were stained with GABA and glutamate antibodies. From these sections, the terminals were reconstructed and the position of 35 input and 21 output synapses mapped. Of the 35 input synapses, 18 (51%) were immunoreactive for GABA, 14 (40%) were immunoreactive for glutamate and 3 (9%) were unlabelled by either antibody. On these terminals, the different classes of input synapses appeared to be intermingled at random with the output synapses made by the afferent, and no pattern govering synapse distribution could be discerned. © 1994 Wiley‐Liss, Inc.