摘要:

AbstractThe distribution of FMRFamidelike peptides was studied in the nervous system of the lobsterHomarus americanusby using immunocytochemical and radioimmunological techniques. By radioimmunoassay FMRF‐amidelike immunoreactivity (FLI) was found in low levels (ca. 1 pmol/mg protein) throughout the ventral nerve cord and in much higher amounts (60–100 pmol/mg protein) in the neurosecretory pericardial organs. Immunocytochemical studies showed FLI in approximately 300–350 cell bodies, and in distinct neuropil regions, neuronal fiber tracts, and varicose endings. Specificity of the immunostaining was tested by preabsorbing the antiserum with FMRFamide, with peptides having similar carboxyl termini to FMRFamide (Met‐enkephalin‐Arg‐Phe, Phe‐Met‐Arg‐Tyr‐amide), with several amidated peptides (α‐melanocyte‐stimulating hormone, substance P, oxytocin), and with proctolin, a peptide found widely distributed in the lobster nervous system. Of these substances, only FMRFamide blocked the staining.In addition to the pericardial organs, significant levels of FLI were found in neurosecretory regions associated with thoracic second roots and in the connective tissue sheath that surrounds the ventral nerve cord. In all three regions, immunocytochemical studies showed the FLI to be localized to fine fibers and associated terminal varicosities lying close to the surface of the tissue, with no obvious target in their immediate vicinity. When examined at the ultrastructural level, the immunoreactive varicosities of the thoracic second roots and of the ventral nerve cord sheaths were found a few microns from the surface of the tissue and contained electron‐dense granules. In the immunoreactive nerve cord sheath endings, in addition to the large, dense granules, small, clear vesicles were found. The appearance and location of these terminals suggest a neurohormonal role for FMRFamidelike peptides in lobsters. The observation that low levels of FLI are found in the hemolymph supports this suggestion. In addition, the localization of FLI to particular neuronal somata, fiber tracts, and neuropil regions suggests possible functional roles for these peptides in (1) integration of visual and olfactory information, (2) function of the anterior and posterior gut, and (3) the cont

ISSN:0092-7317    

DOI:10.1002/cne.902660102

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractIn the preceding paper (Kobierski et al:J. Comp. Neurol. 266:1–15, '87) FMRFamidelike immunoreactivity (FLI) was localized to specific cells and processes in the nervous system of the lobsterHomarus americanus.In an effort to establish a role for this material we have purified and characterized a variety of immunoreactive peptides that can be extracted from the secretory pericardial organs. By using gel‐filtration chromatography and three different HPLC systems, it has been established that little or no authentic FMRFamide is present. Of the major immunoreactive components two peptides were purified in sufficient quantity for microsequence analysis and have been tentatively identified as the octapeptides Ser‐Asp‐Arg‐Asn‐Phe‐Leu‐Arg‐Phe‐amide (FLI 3) and Thr‐Asn‐Arg‐Asn‐Phe‐Leu‐Arg‐Phe‐amide (FLI 4). Both of these are novel neuropeptides with some sequence homology to the previously described FMRFamide family.The pericardial organs release FLI when depolarized with 100 mM K+in the presence of calcium. Between 75 and 80% of this release is accounted for by FLI 3 and FLI 4. One of these peptides (FLI 4) has been synthesized and shown to cochromatograph with the endogenous immunoreactive material. Preliminary studies show that this peptide can act as a modulator of exoskeletal

ISSN:0092-7317    

DOI:10.1002/cne.902660103

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe experiments described in this report were designed to determine whether changing the somatosensory representation in the deep laminae of the hamster's superior colliculus would result in a corresponding reorganization in the visual map in the overlying superficial layers. The somatosensory representation was altered by transecting the infraorbital (IO) nerve on the day of birth. This trigeminal branch supplies, among other targets, the snout and mystacial vibrissa follicles. These peripheral structures compose a major portion of the somatosensory representation in the deep collicular laminae. The effects of these lesions were assessed in anatomical and physiological experiments when the animals reached adulthood.Retrograde tracing with true blue demonstrated a 48% reduction in the number of trigeminocollicular neurons in the partially deafferented subnucleus interpolaris (the main source of trigeminal input to the rodent colliculus–e.g., Killackey and Erzurumlu:J. Comp. Neurol. 201:221–242, '81), but anterograde tracing with horseradish peroxidase (CHRP) and wheat germ agglutinin‐conjugated HRP showed that the terminal field of the trigeminocollicular projection from the deafferented subnucleus was essentially normal. This pathway terminated as a series of patches along the border between thestratum griseum intermediateandstratum album intermediumand encompassed approximately 75% of the rostrocaudal extent of the colliculus.The electrophysiological experiments revealed a marked change in somatosensory collicular topography. There was an underrepresentation of the vibrissae and the entire IO peripheral field in the deep laminae of the nerve‐damaged animals, and neurons with trigeminal ophthalmic and mandibular receptive fields were recorded from portions of the colliculus in which only whisker‐sensitive neurons would be normally isolated. There were no corresponding changes in the organization of the visual representation.These results support the conclusion that the organization of the visual representation in the superficial laminae and the organization of the somatosensory map in the deep layers of the mammalian superior colliculus follow independent developmental

ISSN:0092-7317    

DOI:10.1002/cne.902660104

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe distribution of GABA‐like (GABA‐Li) immunoreactivity in the rat amygdaloid complex was studied by using an anti‐GABA antibody. GABA‐Li positive neurons and processes were present in every nucleus of the complex. Three patterns of immunoreactivity were revealed: (1) the intercalated masses and the lateral olfactory tract nucleus exhibited the most intense staining of the neuropil, and virtually every neuron was labeled, (2) the central and medial nuclei contained intensely labeled neuropil and moderately labeled neurons, and (3) in the remaining nuclei, the neuropil was weakly labeled, and relatively numerous GABA‐Li neurons were present. Our results suggest that: (1) the intercalated masses and lateral olfactory tract nucleus consist of large aggregates of GABA‐Li immunoreactive neurons, and (2) the lateral, basal dorsal, and the posterior cortical nuclei may constitute a significant source of GABAergic connections to other amygdaloid nuclei, in particular to the medial and cen

ISSN:0092-7317    

DOI:10.1002/cne.902660105

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractPause neurons (PNs) are inhibitory neurons close to the midline at the pontomedullary junction that fire tonically and then cease firing just prior to quick eye movements of visual or vestibular origin. Previous physiological evidence has shown that these neurons have a role of central importance in the generation of rapid eye movements in any direction and all major models of ocular motor control incorporate PNs as major elements. In this study in cats, we injected horseradish peroxidase intracellularly into somata or axons of physiologically identified PNs. After appropriate tissue preparation, cell body and axonal reconstructions were performed, with the aid of a camera lucida‐equipped microscope. Fifty‐three PNs were stained and reconstructed. These consisted of 17 cell bodies and dendrites and 36 axons. Seven of these included both cell bodies and axons. PN somas lay close to the midline in the nucleus raphe pontis and centralis superior, had extensive dendritic arborizations tending to arise from either pole of the elongated soma, and had axons which typically crossed the midline and bifurcated into long branches which extended rostrally and caudally, inferior to the medial longitudinal fasciculus. There were major terminal arborizations and boutons in areas just rostral and caudal to the abducens nucleus in areas where two types of premotor neurons, excitatory and inhibitory burst neurons, are concentrated. Many axosomatic contacts were noted. Other terminal arborizations and boutons were found close to the midline in a region rostral to abducens nucleus containing other neurons known to burst prior to quick eye movements, and in the nucleus reticularis gigantocellularis. Rostral stem axons could be traced to the level of the trochlear nucleus and inferior to the medial longitudinal fasciculus. The caudal stem axons could be traced parallel to the midline and inferior to the medial longitudinal fasciculus and as far caudally as the hypoglossal nucl

ISSN:0092-7317    

DOI:10.1002/cne.902660106

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractBy analyzing regional variations of afferent connectivity, we have identified a medial subdivision of feline area 6 (area 6m) which differs from all surrounding sectors of the frontal lobe in its pattern of inputs. Area 6m is located in the ventral bank of the cruciate sulcus and on the adjacent medial face of the frontal, lobe and is partially coextensive with the medial frontal eye field as identified previously in electrophysiological experiments.Area 6m is innervated by axons from visual, association, and oculomotor areas and does not receive projections from somesthetic or somatomotor areas. Cortical sources of input to area 6m include several retinotopically organized extrastriate visual areas (AMLS, ALLS, and PLLS), association areas with strong links to the visual system (area 7, granular insula, posterior ectosylvian gyrus, and cingulate gyrus), and a lateral division of area 6 (area 6l) with oculomotor functions. Thalamic afferents of area 6m derive from the paralamellar ventral anterior nucleus, from a dorsolateral division of the mediodorsal nucleus, and from the rostral intralaminar nuclei. The claustrum and the basolateral nucleus of the amygdala project to area 6m. Projections from area 7, the posterior cingulate area, the ventral anterior nucleus, and the mediodorsal nucleus are spatially ordered in a pattern such that parts of area 6 close to the fundus of the cruciate sulcus receive input from neurons positioned anteriorly in the cortical areas, dorsolaterally in the ventral anterior nucleus, and ventrolaterally in the mediodorsal nucleus.Our results indicate that area 6m probably is involved in the voluntary control of gaze and attention rather than in skeletomotor functions.

ISSN:0092-7317    

DOI:10.1002/cne.902660107

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractExcitatory motor neurons in the leech are cholinergic. By using a combination of intracellular Lucifer yellow injection and indirect immunofluorescence, we localized FMRFamidelike immunoreactivity to a number of the motor neurons innervating longitudinal and dorsoventral muscle in the leech. All excitatory motor neurons innervating longitudinal muscle (cells 3, 4, 5, 6, 8, L, 106, 107, 108) were labeled with an antiserum to FMRFamide, while the inhibitory motor neurons innervating longitudinal muscle (cells 1, 2, 7, 9, 102) were not. The excitatory motor neuron innervating medial dorsoventral muscle (cell 117) was labeled, while the excitatory motor neuron innervating lateral dorsoventral muscle (cell 109) was not. The inhibitory motor neuron innervating dorsoventral muscle (cell 101) was also labeled. Nerve terminals along dorsoventral muscle were also labeled with the antiserum.FMRFamide was bath applied to strips of longitudinal muscle while recording tension, and the muscle's response was compared to its response to the previously identified neuromuscular transmitter ACh. Brief applications of FMRFamide caused a contraction approximately one‐tenth as large as that caused by an equimolar amount of ACh. The muscle response to FMRFamide was unaffected by curare. During extended exposures, FMRFamide caused a maintained contraction in longitudinal muscle without any apparent desensitization of the FMRFamide receptors and occasionally triggered an irregular myogenic rhythm. This extended exposure to FMRFamide caused a post‐exposure potentiation of the longitudinal muscle's response to ACh that shorter applications of FMRFamide did not. Thus FMRFamide may act as a transmitter or modulator in cholinergic motor neurons innervating longitudinal and dorsoventral muscles in the le

ISSN:0092-7317    

DOI:10.1002/cne.902660108

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe intermediate‐filament proteins expressed in the goldfish retina were investigated by immunohistochemistry and by immunoblotting. Polyclonal antibodies that previously had been raised against the goldfish optic nerve neurofilament (ON1and ON2) and glial filament (ON3and ON4) proteins were used in this study. Anti‐ON1/ON2antiserum reacted on a retinal immunoblot with two proteins having molecular weights and isoelectric points corresponding to those of ON1and ON2. Histologically, the most pronounced anti‐ON1/ON2reactivity was observed in the ganglion cell layer of the goldfish retina. The anti‐ON3/ON4antiserum reacted with a single protein on a retinal immunoblot. This protein had a molecular weight and isoelectric point which corresponded to the goldfish optic nerve glial filament proteins. This anti‐serum labeled horizontal cells in retina sections. Three previously unidentified goldfish visual‐pathway intermediate‐filament proteins sharing a molecular weight of 60K were observed on two‐dimensional gels of retinal cytoskeletal proteins and on retinal immunoblots which were probed with a monoclonal antibody which recognizes an epitope common to all intermediate Filament proteins.The possible existence of homologs of mammalian GFAP and vimentin in the goldfish retina was also explored. Antibodies directed against mammalian GFAP and vimentin labeled the Müller fibers and the cone horizontal cells, respectively. However, immunoblot analysis and a comparison of the two‐dimensional gel electrophoresis patterns of goldfish retinal and rat spinal cord cytoskeletal proteins demonstrated a lack of goldfish proteins identical to the mammalian intermediate

ISSN:0092-7317    

DOI:10.1002/cne.902660109

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe thalamic projections to the hippocampal formation and to the subicular and entorhinal areas in the cat have been studied with retrograde transport of horseradish peroxidase (HRP) or wheat germ agglutinin conjugated to HRP (WGA‐HRP) and anterograde transport of WGA‐HRP. Retrograde transport tracers injected in various parts of these cortices resulted in labeled cells in the midline, anterior, and lateral dorsal nuclei. Injections into the hippocampal formation or the subiculum led to retrograde labeling of cells in the reuniens nucleus of the ipsilateral thalamus throughout its rostrocaudal extent, whereas the restricted injections into the dentate gyrus and the inferior region of the hippocampus led to no labeling. Following an injection into the pre‐ and parasubiculum, a large number of labeled cells were seen not only in the reuniens nucleus but in other midline nuclei. In addition, a substantial number of labeled cells were also detected in the anterior and lateral dorsal nuclei, particularly in the anterodorsal nucleus, which contained densely arranged labeled cells throughout almost the entire rostrocaudal extent. An injection into the medial entorhinal area labeled a number of cells in the anterior nuclei and in the reuniens nucleus, particularly its dorsal part. Injections into various subdivisions of the lateral entorhinal area yielded different patterns of distribution of labeled cells in the thalamic nuclei. An injection into the ventromedial division (VMEA) led to abundant labeling of cells in the paraventricular and reuniens nuclei. After an injection into the ventral division (VLEA), numerous labeled cells were detected in the reuniens nucleus and a lesser number in the paraventricular nucleus at anterior levels. When an injection was made into the dorsal division (DLEA), a large number of labeled cells were detected in the reuniens nucleus, and less numerous labeled cells were found in the central medial nucleus. There appears to be a topographic arrangement of cortical projections of the reuniens nucleus. The pre‐ and parasubiculum receive projections from the most medial part of the reuniens nucleus near the midline, and the DLEA receives projections from the medial part of the nucleus. The cells projecting to the VLEA and MEA are distributed in the central part of the reuniens nucleus, and those to the VMEA are distributed in the lateral part. Anterograde experiments were also performed; injections of WGA‐HRP into the reuniens nucleus resulted in terminal labeling in the superficial layers of the subicular area and the neighboring hippocampus and in the entorh

ISSN:0092-7317    

DOI:10.1002/cne.902660110

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY

ISSN:0092-7317    

DOI:10.1002/cne.902660101

出版商:Alan R. Liss, Inc.    

年代:1987

数据来源: WILEY