bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunohistochemical localization of seven different peptides in the human spinal cord
Authors: Chung K. , Carlton S. M. , Westlund K. N. , Briner R. P. 
Published: January 2005

AbstractIt is necessary to study the normal chemical contents in the human spinal cord in order to understand neurochemical changes that might occur under pathological conditions. In the present study, the comparative distribution of seven peptides was examined immunohistochemically in four levels (cervical, C; thoracic, T; lumbar, L; sacral, S) of the human spinal cord by means of the peroxidase‐antiperoxidase technique. The peptides examined included bombesin (BOM), substance P (SP), cholecystokinin (CCK), somatostatin (SOM), methionine‐enkephalin (M‐ENK), vasoactive intestinal polypeptide (VIP), and thyrotropin releasing hormone (TRH). Among the seven peptides examined, four (BOM, CCK, SOM, and TRH) have never been described in the human spinal cord and the present work clearly demonstrates their existence in specific patterns. The terminals that were immunostained for BOM and CCK were localized in high concentration in the superficial dorsal horn (laminae I‐II), in moderate amounts in the lateral part of laminae V and VII, and lesser amounts in the intermediate gray (lamina VII) and the dorsal part of the central gray (lamina X). Whereas BOM showed a similar distribution pattern at all spinal levels, CCK was mainly found in thoracic and lumbar levels. The SOM terminals were localized in the superficial dorsal horn (the highest density in lamina II but very few in lamina I), the intermediolateral cell column, intermediate gray, and central gray. This peptide was more widely distributed in the sacral cord with its terminal field extending into the ventral horn. The TRH terminals were mainly located in the ventral horn. Frequently, TRH terminals were seen adjacent to large ventral horn neurons. Furthermore, many neurons in the ventral and intermediate gray and Clarke's column demonstrated TRH immunoreactivity. The other three peptides (SP, M‐ENK, and VIP) have been previously demonstrated in the human spinal cord and the present study confirmed their general spinal distribution with minor differences.
Amacrine and ganglion cells with corticotropin‐releasing‐factor‐like immunoreactivity in the turtle retina
Authors: Williamson Douglas E. , Eldred William D. 
Published: January 2005

AbstractThis study, which uses immunocytochemical methods at the light microscopical level, examines the cell types in the turtle retina that contain corticotropin‐releasing factor (CRF)‐like immunoreactivity. Two anatomically distinct amacrine cell types are labeled when antiserum directed against ovine CRF is used to label the turtle retina. These cell types each have a different dendritic arborization pattern and regional distribution. Type A cells are found only in the visual streak and have elongated dendritic arborizations that run parallel to the visual streak. These cells arborize primarily in stratum 1 and near the border of strata 2 and 3, with some processes extending into stratum 5. Type B amacrine cells are found only ventral to the visual streak and arborize primarily in a wide band in strata 4 and 5 with sparse dendritic arborizations in stratum 1. No labeled amacrine cells of any type were found dorsal to the visual streak. The asymmetric dendritic arborizations of the type A amacrine cells and the different regional distributions of the A and B cell types suggest that these two amacrine cell types perform distinct physiological functions.In addition to these labeled amacrine cells, there are also some immunoreactive cell bodies in the ganglion cell layer. Rhodamine crystals were applied to the optic tectum to retrogradely label the ganglion cell bodies. Double label studies indicate that some of the rhodamine‐labeled ganglion cells also contain CRF‐like immunoreactivity. The localization of CRF‐like immunoreactivity in two distinct amacrine cell types and in ganglion cells suggests that it may play multiple roles in visual processing in the turtle retina.
Regeneration of muscle axons in the frog is directed by diffusible factors from denervated muscle and nerve tubes
Authors: Kuffler Damien P. 
Published: January 2005

AbstractIn the frog, peripheral muscle axons regenerate after a lesion to reinnervate the original synaptic sites on muscle fibers. Previous experiments in the frog have shown that satellite cells of the nerve tube direct the outgrowth of regenerating muscle axons over distances of many millimeters. In the present experiments, denervated muscle was used as a target for regenerating muscle axons. Muscle and satellite cells of the nerve tube also were placed in filters to determine if their influence on axonal outgrowth was exerted by diffusible factors. Filters were used with a pore size of 0.22 μm. With this pore size, target cells were isolated from physical contact with the surrounding cells; yet an exchange of fluids–and therefore of molecules released by the target cells–could occur across the filter.In the presence of denervated muscle or satellite cells of the nerve tube in filters, regenerating axons turn and grow toward the target cells. This influence on the direction of axonal outgrowth was produced over distances of 6 mm by muscles and 4 mm by cells of the nerve tubes. This directed outgrowth is in marked contrast to the random pattern of outgrowth in the absence of the targets.The present findings set the stage for tissue culture experiments in which the phenomena observed in vivo can be analyzed in terms of mechanisms. The present finding that denervated muscle attracts regenerating axons means that sufficient material may be available for the characterization and isolation of the relevant molecules.
Differential colocalization of neuropeptide Y‐ and methionine‐enkephalin‐Arg6‐Gly7‐Leu8‐ like immunoreactivity in catecholaminergic neurons in the rat brain stem
Authors: Murakami Sadatsugu , Okamura Hitoshi , Pelletier Georges , Ibata Yasuhiko 
Published: January 2005

AbstractThe present study, using a combination of catecholamine (CA) histofluorescence and peptide immunocytochemistry in the same tissue sections, investigated the coexistence of neuropeptide Y (NPY) and methionine‐enkephalin‐Arg6‐Gly7‐Leu8 (MEAGL)‐like immunoreactivity (LI) in catecholaminergic neurons of colchicine‐treated rat brain stems. Of the total number of catecholaminergic neurons in the A1/C1, A2/C2, A3, A4, and A6 regions approximately 83, 28, 98, 76, and 36%, respectively, contained both NPY‐LI and CA. Of the total number of catecholaminergic neurons in A1/C1, A2/C2, A3, and A5 regions, approximately 47, 4, 8, and 17%, respectively, contained both MEAGL‐LI and CA. Moreover, about 24% of the catecholaminergic neurons in the A1/C1 region contained both NPY‐ and MEAGL‐LI. Neither the noradrenergic neurons (A7) in the pons nor any of the dopaminergic neurons in the midbrain (A8, A9, A10) contained NPY‐ or MEAGL‐LI. Neurons containing both NPY‐ and MEAGL‐like immunoreactive peptides without CA were not found in the rat brain stem.These findings indicate that catecholaminergic neurons in the brain stem of the rat can be subdivided into distinct subgroups on the basis of the coexistence of specific peptides.
Structure‐function relationships in rat brainstem subnucleus interpolaris: V. Functional consequences of neonatal infraorbital nerve section
Authors: Jacquin Mark F. 
Published: January 2005

AbstractIn a prior study (Jacquin et al., '86c), the response properties and projections of neonatally axotomized trigeminal (V) primary afferents were studied in the adult rat. Here, single‐unit recording, electrical stimulation, and receptive field (RF) mapping techniques were also used to assess the functional consequences of neonatal infraorbital nerve section upon postsynaptic cells in V brainstem subnucleus interpolaris (SpVi). Of 904 cells studied, 385 were from normal adults and 519 were from neonatally deafferented adults. Infraorbital nerve section at birth resulted in: (1) a substantial reduction in those areas of SpVi containing cells with infraorbital RFs, and only a slight increase in areas solely responsive to noninfraorbital surfaces, (2) an absence of orderly topography within cells expressing regenerate primary afferent inputs, (3) a slight increase in mean discharge latency to V ganglion or thalamic shocks, (4) an increased relative percentage of cells orthodromically activated by diencephalic or cerebellar shocks, (5) a decreased relative percentage of mystacial vibrissa‐sensitive local circuit neurons, with a corresponding increase in local circuit nociceptors and unresponsive cells, (6) an increased relative percentage of mystacial nociceptors, vibrissae, guard hair, and/or skin sensitive cells projecting to thalamus and/or cerebellum, (7) an increased percentage of local circuit neurons with RFs including more than one vibrissa, whereas projection neurons did not differ from normal in the number of vibrissae composing their RFs, and (8) an increased relative percentage of cells expressing interdivisional and intermodality convergence, split RFs, spontaneous activity, directional, high velocity, and neuroma sensitivity.Thus neonatal nerve section produces changes in topography, inputs, projection status, and responses of surviving postsynaptic neurons. Although many of these centrally observed alterations can be attributed to altered peripheral projections in axotomized V primary afferents, others must reflect central reorganization. The central mechanisms responsible for the synthesis of deafferentation‐induced RFs remain to be elucidated.
HRP study of cerebellar corticonuclear‐nucleocortical topography of the dorsal culminate lobule—lobule v—in a prosimian primate (Galago): with comments on nucleocortical cell types
Authors: Haines D. E. 
Published: January 2005

AbstractThe distribution of retrogradely labeled cerebellar nucleocortical (NC) cells and anterogradely labeled corticonuclear (CN) fibers was investigated in a prosimian primate (Galago) by means of horseradish peroxidase as a tracer. Iontophoretic and pressure injections were made in the cortex of lobule V and the resultant patterns of label were determined in the cerebellar nuclei. Following iontophoretic injections in vermal (zone A), intermediate (zones C1, C3), and lateral (zone D) cortices, retrogradely labeled cells were present in medial (NM), anterior interposed (NIA), and lateral (NL) cerebellar nuclei, respectively. Larger injections that involved A‐C2 zones resulted in NC label in NM, medial NIA, and throughout the posterior interposed (NIP) nucleus. Retrogradely labeled NC cells were usually found in areas of their respective nuclei that also contained anterogradely filled CN axons. In addition, retrogradely labeled cells were seen contralateral to some injections. Contralateral NC cells were found mainly in the NM and NIP and seemed to be labeled in response to injections that involved zones A, C2, and possibly x on the opposite side. No contralateral CN labeling was seen. It appears that the NC projections of lobule V follows a basic zonal (sagittal) orientation and that most are reciprocal to CN fibers arising from the same cortical area.There is evidence of zonal heterogeneity in the ipsilateral NC projection. Iontophoretic injections placed in adjacent zones resulted in markedly different numbers of retrogradely labeled NC cells in their respective nuclei. Also, after pressure injections that involved two or more adjoining zones, the number of labeled NC cells was large in one nucleus but minimal in an adjacent nucleus. These data suggest that different cerebellar cortical zones have quantitatively different NC input; this may relate to specific functional demands placed on each nucleus and its corresponding cortical zone.On the basis of their known connections, it is hypothesized that there are at least three and possibly four categories of NC cells. Ipsilateral reciprocal NC cells are found in, or on the periphery of, CN terminal fields formed by axons originating from the same cortical area to which the NC cells project. Ipsilateral nonreciprocal NC cells are located outside the CN terminal field and may even be found in an adjacent nucleus; these are fewer in number than the reciprocal population. Contralateral NC cells are found in the opposite cerebellar nuclei and appear to be topographically related to the ipsilateral contingent as well as to the injection site. It is probable that different types of NC cells have individualized functional characteristics.
Functional subdivisions in the auditory cortex of the guinea pig
Authors: Redies H. , Sieben U. , Creutzfeldt O. D. 
Published: January 2005

AbstractThe auditory fields in the cortex of the guinea pig were investigated with microelectrode mapping techniques. Pure tones of varying frequencies and amplitudes were used as acoustic stimuli. Mainly, multiunit activity was recorded.A large tonotopic area is found in the anterior half of the auditory cortex. This area is named the anterior field (field A). Frequency tuning curves of multiunits in field A are generally narrow. Responses to tone stimuli are strong, and latencies are short. Low best frequencies are represented rostrally, high best frequencies caudally. The tonotopy is continuous and quite regular. Field A is narrow dorsally and becomes gradually broader ventrally. Correspondingly, the isofrequency lines slightly diverge from dorsal to ventral.Caudal to the first field, there is a second, smaller tonotopic area. It lies in the dorsal half of the posterior auditory cortex and is therefore named the dorsocaudal field (field DC). The frequency specificity of the cell clusters in this area is as strong as in field A, but the tonotopy is discontinuous: In the dorsal half of field DC, high best frequencies (16‐32 kHz) are represented rostrally; the low frequencies (0.5‐2.8 kHz) are represented immediately caudal to the high frequencies, while the intermediate frequencies are missing. Ventrally in field DC, the frequency representation is more complete. Except for this discontinuous map, we did not notice any differences between fields A and DC. A third tonotopic field was found rostral to field A. This field extends over a surface of less than 1 mm2 and was named the small field (field S). It contains a complete representation of the frequency range; high best frequencies are located rostrally, low frequencies caudally. The response latencies are slightly longer in field S than in fields A or DC, and the tuning curves are broader.A broad strip of nontonotopic cortex (auditory belt) surrounds fields A and DC caudally. We subdivided this area into the dorsocaudal and the ventrocaudal belt region. In both areas, tuning curves are often broad, and response latencies are longer than in the tonotopic cortex. In the dorsocaudal belt, most multiunits react with a phasic on‐response to pure tones; in the ventrocaudal belt, tonic responses occur more frequently. Another nontonotopic region is located in the anterior auditory cortex, rostral to the tonotopic fields, and was therefore named the rostral belt. Tuning curves in this area are broad, latencies are short, and reponse thresholds are often high.In the discussion, the guinea pig is compared with other mammalian species. Species‐specific features in the organization of the tonotopic cortex of the guinea pig are revealed.
Cranial motor neurons contain either galanin‐ or calcitonin gene‐related peptidelike immunoreactivity
Authors: Moore Robert Y. 
Published: January 2005

AbstractThe demonstration of coexistence of a peptide or peptides in neurons that produce a small molecule neurotransmitter has become increasingly frequent. The calcitonin gene‐related peptide (CGRP) is known to be colocalized in the cholinergic neurons of both cranial and spinal motor nuclei. The present study demonstrates that all somatic motor cranial nerve nuclei contain CGRP‐and galaninlike immunoreactivity. The perikaryal content of both peptides is increased by colchicine pretreatment and by transecting axons arising from the perikarya, and both peptides are found in nerve fibers innervating striated musculature. CGRP‐ and galaninlike immunoreactivity appear to be present in different populations of neurons. In contrast to CGRP, galaninlike immunoreactivity was not detected in spinal motor neurons. These observations suggest that galanin and CGRP participate in the process of synaptic transmission at the neuromuscular junction of cranial motor neurons.
Effects of very early monocular and binocular enucleation on primary visual centers in the tammar wallaby (Macropus eugenii)
Authors: Marotte L. R. , Flett D. L. , Mark R. F. 
Published: January 2005

AbstractThe role of retinal afferents and their binocular interactions in the development of mammalian primary visual centers has been studied in the marsupial wallaby. Monocular and binocular enucleation was performed prior to any retinal innervation of the visual centers. After monocular enucleation retinal projections were traced by horseradish peroxidase histochemistry and compared with those in normal animals and those during development. The topography of retinal projections to the superior colliculus and the dorsal lateral geniculate nucleus after monocular enucleation was determined by making retinal lesions and tracing the remaining projections with horseradish peroxidase. The position and nature of the filling defects in terminal label were compared with controls with similarly placed lesions.The superior colliculus and dorsal lateral geniculate nucleus ipsilateral to the remaining eye were shrunken. Projections to the ipsilateral superior colliculus, ipsilateral accessory optic nuclei, and ipsilateral suprachiasmatic nucleus, although enlarged, never approached the density contralaterally, as was also the case during normal development. The expanded projection in the ipsilateral superior colliculus came primarily from temporal and ventral retina. In the dorsal lateral geniculate nucleus, terminal bands and cellular laminae, although not identical to normal, did develop. During normal development overlap of afferents from the two eyes occurs in the binocular region. The decrease in volume of the nucleus ipsilateral to the remaining eye after monocular enucleation suggests that the monocular region disappears in the absence of appropriate input and the binocular region survives. Contralaterally there was no decrease in volume, compatible with this idea. The topography of retinal projections supports this interpretation. It was normal contralaterally while ipsilaterally it was appropriate for the normal binocular region. There was an expansion of the projection along the lines of projection in what would normally be binocular regions of the nucleus, where retinal afferents failed to segregate in the absence of binocular competition.After binocular enucleation the α and β segments of the dorsal lateral geniculate nucleus were still recognizable but cell‐sparse zones were absent, as was the characteristic orientation of primary dendrites of geniculocortical cells.There are rigid developmental constraints operating on the innervation of territory by retinal afferents from the two eyes, and many features of the mature pattern arise without binocular interactions during development.
Structure and histogenesis of the principal sensory nucleus of the trigeminal nerve: Effects of prenatal exposure to ethanol
Authors: Miller Michael W. , Muller Susan J. 
Published: January 2005

AbstractClinical and experimental evidence shows that prenatal exposure to ethanol causes craniofacial malformations, microcephaly, and abnormal development of the central nervous system. This study describes the effects of ethanol on the development of the principal sensory nucleus of the trigeminal nerve (PSN). The offspring of two groups of rats were examined. Pregnant females in one group were fed a liquid diet containing 6.7% (v/v) ethanol (Et) and rats in the other group were fed an isocaloric liquid control diet (Ct). Each pregnant rat was administered [3H]thymidine on one day during the period from gestational day (G) 10 to G22. After pups grew to 30 days of age, they were killed and their brains were processed by an autoradiographic procedure.Qualitatively, the PSN of Ct‐ and Et‐treated rats appeared similar; they were composed chiefly of small neurons and a few scattered large neurons. On the other hand, quantitative analyses revealed significant differences between both groups. Although the volume of the PSN of Et‐treated rats was not significantly different (‐3.2%) than that for Ct‐treated rats, the PSN of Et‐treated rats had significantly (P <0.01) fewer (30.0%) neurons than did the PSN of Ct‐treated rats. The number of the small neurons, but not of the large neurons, was affected most by the ethanol exposure. Prenatal exposure to ethanol also altered the generation of PSN neurons. Most neurons in the PSN of Ct‐treated rats were born between G12 and G15, the small neurons being generated before the large neurons. In Et‐treated rats, too, small neurons were born before the large neurons; however, the time frame of neuronogenesis was delayed as it occurred between G13 and G16.Thus, prenatal exposure to ethanol produces profound developmental abnormalities that lead to permanent alterations in the structure of the mature central nervous system.
Topography of cones and rods in the tree shrew retina
Authors: Müller Brigitte , Peichl Leo 
Published: January 2005

AbstractThe topographical distribution of cones and rods in the tree shrew retina was analysed quantitatively in whole‐mounted retinae and horizontal semithin sections stained with cresyl violet or toluidine blue. The outer nuclear layer consists of a single layer of photoreceptor nuclei with the rod nuclei slightly displaced towards the outer plexiform layer. This facilitated quantification of the photoreceptor populations. The density of cones ranges from 12,000/mm2 in the peripheral retina to a maximum of 36,000/mm2 in the inferior retina. Unlike ganglion cell density, the density of cones does not peak in the temporal retina. Rod density, between 500/mm2 and 3,500/mm2, also peaks in the inferior retina, but not in the same region as cone density. Rods constitute from 1 to 14% of the photoreceptor population, depending on retinal location, and have a local minimum at the central area. Amongst the cones a regularly arrayed subpopulation of presumed blue‐sensitive cones is distinguished by its special staining properties. These cones constitute between 4 and 10% of the cone population depending on retinal location. A second, irregularly spaced, subpopulation of possibly pathological cones is also described.