摘要:

AbstractImmunocytochemical analysis of the thoraco‐abdominal ganglia of the fliesDrosophila melanogasterandCalliphora vomitoriarevealed neurons displaying substance P‐ (SPLI), FMRFamide‐(FLI), and cholecystokinin‐like (CCKLI) immunoreactivity. It could be demonstrated that a number of neurons contain peptides reacting with antisera against all the three types of substances, others were either FLI or CCKLI alone. No neurons displayed only SPLI. Instead, the total number (about 30) of SPLI neurons constitute a subpopulation of the FLI/CCKLI neurons. Many of the identifiable immunoreactive neurons seem to be homologous in the two fly species. One set of six large neurons, termed ventral thoracic neurosecretory neurons (VTNCs), are among those that are SPLI, FLI, and CCKLI in bothDrosophilaandCalliphora. With the present immunocytochemical technique, the detailed morphology of the VTNCs could be resolved. These neurosecretory neurons supply the entire dorsal neural sheath of the thoraco‐abdominal ganglia with terminals, thus forming an extensive neurohaemal area. The VTNCs also have processes connecting the thoracic neuromeres to the cephalic suboesophageal ganglion, as well as extensive arborizations in the thoracic ganglia, suggesting an important role in integrating and/or regulating large portions of the central nervous system, in addition to their neurosecretory function. Most of the other SPLI, FLI, and CCKLI neurons in the thoraco‐abdominal ganglia seem to be interneurons. However, there are four FLI neurons that appear to be efferents innervating the hindgut and a few abdominal FLI and CCKLI neurons may be additional neurosecretory cells. From the present study it appears as if neuropeptides related to substance P, FMRFamide and CCK have roles as neurotransmitters/neuromodulators and circulating neurohormones inDrosophilaan

ISSN:0092-7317    

DOI:10.1002/cne.902940202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe purpose of this study was to test whether a new retrograde tracer, the B subunit of cholera toxin conjugated to colloidal gold particles (Ctb‐gold), was taken up and transported by neurons in the central nervous system of the rat. Retrograde transport of CTB‐gold was assessed from axon terminals, from damaged nerve fibers, and from axons of passage. For light microscopy, CTB‐gold was visualized by silver intensification; for electron microscopy, sections were silver‐intensified with or without subsequent gold toning.Retrogradely transported CTB‐gold was detected in neurons after survival times of 12 hours to 42 days and appeared as black punctate deposits in perikarya and proximal dendrites at the light microscope level. Ultrastructurally, the deposits were usually associated with lysosomes.Injections of CTB‐gold into the caudal ventrolateral medulla or into the lateral horn of the spinal cord gave small well‐defined injection sites and resulted in retrograde labelling in medullary neurons in the same locations as similarly placed injections of wheat germ agglutinin‐horseradish peroxidase. When injected into the superior cervical ganglion, CTB‐gold was transported to nerve cell bodies in the spinal cord, but application of CTB‐gold to the cut cervical sympathetic trunk did not label neurons in the spinal cord. Injection of CTB‐gold into the nodose ganglion retrogradely labelled neurons in the dorsal motor nucleus of the vagus and the nucleus ambiguus. CTB‐gold was not transported anterogradely from injections sites within the medulla.Nerve fibers and cell bodies containing neuropeptides, monoamines, or neurotransmitter‐synthesizing enzymes were readily immunostained after silver intensification of retrogradely transported CTB‐gold. Immunoreactivity for neuropeptides and enzymes was also demonstrated ultrastructurally after silver intensification and gold toning.These results show that CTB‐gold is retrogradely transported from nerve terminals and fibers of passage but not from damaged axons. CTB‐gold gives well‐localized injection sites and persists in neurons for weeks. Transported CTB‐gold is easily visualized and its detection is compatible with light and electron microscopic immunocytochemistry. These properties make CTB‐gold a valuable tool for studying the connectivity and neurochemistry of pa

ISSN:0092-7317    

DOI:10.1002/cne.902940203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractCorticotropin‐releasing factor and enkephalin‐containing neurons are found in the paraventricular nucleus of the rat hypothalamus. Their immunocytochemical distribution suggests that a subpopulation of neurons of the paraventricular nucleus might contain both peptides. The present study describes the coexistence of corticotropin‐releasing factor and enkephalin in parvicellular neurons of the paraventricular nucleus. Immunocytochemical labeling of peptides was combined with in situ hybridization of mRNA to visualize peptide and mRNA labeling in the same tissue section. This resulted in several observations: (1) neurons labeling for the peptide corticotropin‐releasing factor also contain the mRNA to synthesize corticotropin‐releasing factor, (2) neurons labeling for the peptide enkephalin also contain the mRNA to synthesize the peptide enkephalin, (3) a subpopulation of corticotropin‐releasing factor neurons contains the mRNA to synthesize enkephalin, and (4) a subpopulation of enkephalin neurons contains the mRNA to synthesize corticotropin‐releasing factor. A large percentage of enkephalin immunoreactive neurons contains corticotropin‐releasing factor mRNA, where as a smaller percentage of corticotropin‐releasing factor immunoreactive neurons contains enkephalin mRNA. These double‐labeled neurons are present throughout the rostral‐caudal extent of the paraventricular nucleus; the majority of these neurons is present in the medial parvicellular pa

ISSN:0092-7317    

DOI:10.1002/cne.902940204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThree classes of neurons within the lateral tegmental field of the rat medulla having different target projections were identified by retrograde labelling with three different fluorescent tracers. Labelled bulbospinal premotor and propriobulbar interneurons of the ventral respiratory group and vagal motoneurona of nucleus ambiguus formed partially intermingled longitudinal columns encompassed within a common region of the lateral tegmental field. Labelled neurons of each class were organized in a nonuniform distribution within these columns forming subdivisions distinguished by neuron morphology, orientation, and target projection. The three major rostrocaudal divisions of the ventral respiratory group (VRG) previously identified in the cat and rabbit were identified here in the rat, suggesting a common pattern of VRG organization among these species.

ISSN:0092-7317    

DOI:10.1002/cne.902940205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractBulbospinal and propriobulbar respiratory neurons of the ventral respiratory group and catecholamine neurons of the A1 and C1 cell groups were simultaneously labelled in the rat medulla by a combination of retrograde tracing and immunohistochemical identification. The ventral respiratory group and catecholamine cell groups form adjacent, parallel cell columns in the lateral tegmental field of the ventrolateral medulla. The ventral respiratory group is located immediately dorsal to the A1 and C1 groups, although some A1 neurons are intermingled with neurons of the rostral ventral respiratory group, and some C1 neurons are intermingled with those of the Bötzinger complex. The proximate populations of respiratory, catecholamine, and (presumptive) cardiovascular neurons identified in this study provide further support to the hypothesis that this regin of the lateral tegmental field of the ventrolateral medulla is a site of cardiorespiratory coordination

ISSN:0092-7317    

DOI:10.1002/cne.902940206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe mammalian cerebellum is divided into multiple parasagittal compartments as defined by the organization of afferent and efferent projections and by the pattern of expression of several biochemical markers. One such marker is the antigen zebrin I, a 120 kD polypeptide of unknown function that is expressed differentially by a subset of Purkinje cells. Zebrin I+ Purkinje cells are grouped into an array of 14 parasagittal bands interposed by zebrin I− compartments. This Purkinje cell compartmentation corresponds to compartments in the olivocerebellar projection. The afferent axon compartments are present prior to the expression of the mature zebrin I phenotype, thus raising the possibility that differential afferent input regulates the zebrin I phenotype of the target of that input. Lesion studies in the neonate preclude a role for afferent inputs in the regulation of zebrin I expression postnatally, but a prenatal role in commitment still remains open. To explore this possibility, cerebellar anlagen were dissected from embryos at embryonic days 12–15, that is, prior to any contact with afferents, and transplanted ectopically into adult hosts. In the first series of experiments, the grafts were placed into the anterior chamber of the eye, and in the second series, into cavities prepared in the neocortex. Grafts were allowed to mature and then were immunoperoxidase or immunofluorescence stained for zebrin I immunoreactivity. Zebrin I was expressed by grafted Purkinje cells in cortico and in oculo. Double‐labelling experiments confirmed that both the zebrin I+ and the zebrin I− phenotypes were present. The zebrin I immunoreactivity revealed that the zebrin I+ Purkinje cells resemble those in situ with an extensive dendritic arborization that extends through the molecular layer perpendicular to the long axes of the folia. In conclusion, the present data suggest that afferent input does not play a role in the determination of the zebrin I phenotype of Purkinj

ISSN:0092-7317    

DOI:10.1002/cne.902940207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThyrotropin‐releasing hormone stimulates vagally mediated gastric acid secretion and motility by an undefined central mechanism in the rat. The present study sought to determine the anatomical basis for this stimulatory effect by examining the ultrastructural relationship of nerve terminals immunoreactive for thyrotropin‐releasing hormone with the dendrites of gastric vagal motoneurons. A light and electron microscopic double immunostaining technique was employed using the beta subunit of unconjugated cholera toxin as a neural tracer. Cholera toxin (50 μl, 0.25%) was injected into the ventral stomach musculature in five rats. After 72 hours' survival, animals were sacrificed by transcardiac perfusion fixation. Retrogradely transported choleratoxin was immunocytochemically localized in vagal gastric motoneurons and their dendrites in the dorsal motor nucleus of the vagus and nucleus of the solitary tract, alone or in combination with the immunocytochemical localization of thyrotropin‐releasing hormone.Ultrastructural analysis of double‐labeled material revealed thyrotropin releasing hormone‐immunoreactive nerve terminals making asymmetric synaptic contacts on the retrogradely labeled dendrites of vagal gastric motoneurons. Nerve terminals immunoreactive for thyrotropin‐releasing hormone also made asymmetric and symmetric synaptic contacts with unlabeled dendrites of undetermined perikaryal origin. In addition, nonsynaptic varicosities immunoreactive for thyrotropin‐releasing hormone were frequently observed in the vagal nuclei. The synaptic contacts between thyrotropin‐releasing hormone‐immunoreactive nerve terminals and vagal gastric motoneuronal dendrites provide one possible basis for the profound stimulatory effect of central thyrotropin‐releasing hormone on gastric

ISSN:0092-7317    

DOI:10.1002/cne.902940208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractImmunohistochemistry was utilized to investigate the light and electron microscopic localization of neurotensinlike immunoreactive (NT) amacrine cells in the chicken retina. The NT cells possess oval cell bodies (7 μm in diameter) that are located in either the second or third tier of cells from the border of the inner nuclear and inner plexiform layers. The processes of such cells extend into the inner plexiform layer where they ramify as a narrow plexus in sublamina 1 and as a broad plexus in sublaminas 3 and 4. Additionally, stained processes are observed occasionally within sublamina 5.At the ultrastructural level, NT‐positive somas exhibit a rather dense and evenly distributed peroxidase reaction product throughout their cytoplasm. The nucleus of NT amacrine cells possess a round, unindented nuclear membrane. NT‐immunoreactive processes in the inner plexiform layer interact synaptically only with non‐NT cells. NT processes receive synaptic input mainly from the processes of amacrine cells and to a lesser degree from bipolar cells. The large majority of NT‐stained varicosities form presynaptic contacts onto the processes of amacrine cells, but are also presynaptic to bipolar cell axon terminals. Moreover, each of the above synaptic relationships can be identified in each of sublaminas 1 and 3 to 4 of the inner plexiform layer. In addition, NT processes are presynaptic to processes devoid of synaptic vesicles that may originate from ganglion cells. Finally, NT processes occasionally form synaptic contacts onto somas situated in the most proximal row of the inner nucle

ISSN:0092-7317    

DOI:10.1002/cne.902940209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractMedial agranular cortex (AGm) is a narrow, longitudinally oriented region known to have extensive corticocortical connections. The rostral and caudal portions of AGm exhibit functional differences that may involve these connections. Therefore we have examined the rostrocaudal organization of the afferent cortical connections of AGm by using fluorescent tracers, to determine whether there are significant differences between rostral and caudal AGm. Mediolateral patterns have also been examined in order to compare the pattern of corticocortical connections of AGm to those of the laterally adjacent lateral agranular cortex (AGl) and medially adjacent anterior cingulate area (AC).In the rostrocaudal domain, there are notable patterns in the connections of AGm with somatic sensorimotor, visual, and retrosplenial cortex. Rostral AGm receives extensive afferents from the caudal part of somatic sensorimotor area Par I, whereas caudal AGm receives input largely from the hindlimb cortex (area HL). Middle portions of AGm show an intermediate condition, indicating a continuously changing pattern rather than the presence of sharp border zones. The whole of the second somatic sensorimotor area Par II projects to rostral AGm, whereas caudal AGm receives input only from the caudal portion of Par II. Visual cortex projections to AGm originate in areas Oc1, Oc2L and Oc2M. Connections of rostral AGm with visual cortex are noticeably less dense than those of mid and caudal AGm, and are focused in area Oc2L. The granular visual area Oc1 projects almost exclusively to mid and caudal AGm. Retrosplenial cortex has more extensive connections with caudal AGm than with rostral AGm, and the agranular and granular retrosplenial subregions are both involved. Other cortical connections of AGm show little or no apparent rostrocaudal topography. These include afferents from orbital, perirhinal, and entorhinal cortex, all of which are bilateral in origin.In the mediolateral dimension, AGm has more extensive corticocortical connections than either AGl or AC. of these three neighboring areas, only AGm has connections with the somatic sensorimotor, visual, retrosplenial and orbital cortices. In keeping with its role as primary motor cortex, AGl is predominantly connected with area Par I of somatic sensorimotor cortex, specifically rostral Par I. AGl receives no input from visual or retrosplenial cortex. Anterior cingulate cortex has connections with visual area Oc2 and with retrosplenial cortex, but none with somatic sensorimotor cortex. Orbital cortex projections are sparse to AGl and do not appear to involve AC.The rostrocaudal topography demonstrated within AGm is consistent with known functional differences between rostral and caudal AGm, suggesting that rostral AGm be considered a multimodal association area with properties of supplementary motor cortex. In addition, all of AGm appears to represent a frontal eye field. The mediolateral organization described indicates that AGm is distinct from the neighboring areas AGl and AC because of its more diverse corticocortical connections.

ISSN:0092-7317    

DOI:10.1002/cne.902940210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractGalanin‐like immunoreactivity (GAL‐ir) was examined within the basal forebrain and adjacent regions of eight young adult New World monkeys (Cebus apella), one aged Old World monkey (Macaca mullata), and eight humans without clinical or pathological evidence of neurological disease. All monkeys demonstrated similar patterns of immunoreactive profiles characterized by a continuum of GAL‐in magnocellular neurons located within the medial septum, diagonal band nuclei, and nucleus basalis. Colocalization experiments revealed that most (>90%) of GAL‐ir basal forebrain neurons also expressed the receptor for nerve growth factor (NGFR), an excellent marker for primate cholinergic basal forebrain neurons. A few smaller parvicellular GAL‐ir neurons were also observed within the monkey basal forebrain. In contrast, identical cytochemical experiments revealed that virtually none of the magnocellular neurons within the basal forebrain of humans were GAL‐ir. Rather, a network of GAL‐containing fibers and terminal‐like profiles were observed encompassing the magnocellular cholinergic neurons in humans. This immunohistochemical species difference does not appear to be mediated by procedural or technical factors since human brains contained numerous GAL‐ir perikarya and fibers within adjacent regions including the bed nucleus of the stria terminalis and medial hypothalamus. These data demonstrate that there is a prominent phylogenetic transformation in primates with respect to the processing of GAL‐mediated information. This species difference potentially relates to the severe basal forebrain degeneration reported in human dementias and illustrates the possible need for a reevaluation of the use of monkeys as an animal model of human basal forebrain‐related

ISSN:0092-7317    

DOI:10.1002/cne.902940211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY