摘要:

AbstractThe organization of the projections from the cingulate cortex to the striatum in the monkey was studied using the retrograde tracers Lucifer Yellow conjugated to dextran amines and horseradish peroxidase conjugated to wheat germ agglutinin. These tracers were injected into the different regions of the ventral (limbic) striatum and the dorsal (sensorimotor) striatum. The shell region of the nucleus accumbens was defined using calbindin‐D28Kimmunohistochemistry. Following injections into the ventral striatum, there are numerous retrogradely labeled neurons in the various regions of the primate cingulate cortex, most of which are derived from layer V. The cytoarchitectural subdivisions of cingulate cortex include the anterior cingulate cortex, areas 25, 24a–c, and 24a'–c', and the posterior cingulate cortex, areas 23a–c, 29, 30, and 31. There is a topographical organization of the projections from these different cingulate areas to the ventral and dorsal striatum. The medial ventral striatum receives input from the rostral part of the anterior cingulate cortex (areas 25 and 24a, b). The shell region of the nucleus accumbens receives fibers from areas 25, 24a,b, and 24a',b'. Projections to the central ventral striatum including the core of the nucleus accumbens are derived primarily from areas 25, 24a, 24b, and the medial part of area 24c. However, few labeled cells are detected in areas 24c and 24c'. The lateral ventral striatum receives input primarily from areas 24b, 24b' and 23b and medial portion of area 24c. The medial ventral striatum and the shell of the nucleus accumbens have a similar distribution of labeled cells, such that these regions derive their input almost entirely from the rostral anterior cingulate cortex. In contrast to the ventral striatum, the dorsal sensorimotor striatum receives projections from areas 24c, 24c' 23c and 31. These arise primarily from the lateral portion of lower bank and the fundus of the cingulate sulcus.Our results demonstrate that areas 24c, 24c' and 23c, the lateral portion of the lower bank and the fundus of the cingulate sulcus project to the dorsal sensorimotor striatum. The medial portion of the lower bank of the cingulate cortex projects to the ventral striatum including the core of the nucleus accumbens. Different projections to striatum from discrete subdivisions of cingulate cortex indicate that these areas are heterogeneous and have different functions such that the fundus of the cingulate sulcus is related to skeletomotor function, whereas the medial portion of the lower bank of the cingulate sulcus is associated with the limbic‐related and association cortical function. The lateral portion of the lower bank may be a transition area and related to both motor and limbic

ISSN:0092-7317    

DOI:10.1002/cne.903500302

出版商:Wiley‐Liss, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractFluorescent double retrograde‐tracing studies combined with fluorescent immunostaining for serotonin were carried out to determine the potential patterns of divergence in axonal projections to autonomic and somatic motor sites from medullary raphe and parapyramidal neurons. Injections (20–60 nl) of combinations of fluorescent retrograde tracers (Fast Blue, fluoro‐gold, green latex microspheres, Diamidino Yellow) were made into the intermediolateral cell column (IML) of the spinal cord and the brainstem lateral tegmental field or ventral horn of the lumbar spinal cord of male Wistar rats. The animals were perfused after a 7–10‐Day survival period, and the brains were removed, sectioned (50μm), and immunostained for serotonin.Following injections of different retrograde‐tracer substances into the IML of the thoracic cord and the ventral horn of the lumbar cord, 36% of the neurons with axon collateral projections to the IML and the lumbar ventral horn were serotoninergic. Following injections of different retrograde‐tracer substances into the IML and the lateral tegmental field, 26% of the neurons with axon collateral projections to the IML and the lateral tegmental field were serotoninergic. Many of the medullary neurons with projections to the lateral tegmental field and the lumbar cord were located dorsal and lateral to those neurons with projections to the IML. The results indicate that serotoninergic and nonserotoninergic neurons of the midline raphe system and parapyramidal region have axon collateral branches to the IML and the lateral tegmental field or the IML and the lumbar ventral horn. These projection neurons may form the anatomical substrate for the integration of autonomic and somatic

ISSN:0092-7317    

DOI:10.1002/cne.903500303

出版商:Wiley‐Liss, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractUsing several cell‐specific markers, the pattern of proliferation, morphogenesis, and neuronal differentiation of theDrosophilalarval stomatogastric nervous system (SNS) was analyzed. In the late embryo, four SNS ganglia (frontal ganglion, hypocerebral ganglion, paraesophageal ganglion, ventricular ganglion) can be distinguished. In the early embryo, the precursor cells of the SNS (SNSPs), being an integral part of the anlage of the esophagus, undergo four synchronous rounds of division. Subsequently, SNSPs segregate from the esophageal epithelium in a complex and stereotyped pattern. The majority of SNSPs invaginate and transiently form three (rostal, intermediate, caudal) pouches that, after separating from the esophagus, become epithelial vesicles. At later stages, these SNSPs gradually lose their epithelial phenotype. Starting at the anterior‐dorsal tip of each vesicle, SNSPs dissociate from one another and migrate to the various locations where they differentiate as neurons. Cells of the rostral and intermediate vesicle contribute to the frontal ganglion; the hypocerebral ganglion develops from the intermediate vesicle, the paraesophageal ganglion from the rostral vesicle, and the ventricular ganglion from the caudal vesicle. In addition to the invaginating SNSPs, several distinct groups of SNSPs delaminate as individual cells from the esophageal epithelium. Three clusters of SNSPs delaminate from a region anterior to the rostral pouch; a single SNSP delaminates from the tip of each pouch. All delaminates from the tip of each pouch. All delaminating SNSPs contribute to the frontal ganglion. A significant number of SNSPs undergo cell death. In the late embryo, the stomatogastric ganglia are interconnected by the recurrent nerve and esophageal nerves. The frontal ganglion projects to the brain via the frotal connectives. Both recurrent nerve and frontal connectives are pioneered by small subpopulations of early differentiating stomatogastric neurons that most likely derive from among the dSNSPs and iSN

ISSN:0092-7317    

DOI:10.1002/cne.903500304

出版商:Wiley‐Liss, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractA polyclonal rabbit antibody was raised against a synthetic peptide fragment located at the C‐terminal end of turkey β‐endorphin (β‐END) and used to analyze the distribution of β‐END‐immunoreactive‐like structures in the quail and chicken brain. Three major groups of immunopositive cells were detected in the preoptic area‐hypothalamus complex. A thin layer of immunopositive cells was parallel and adjacent to the ventral edge of the brain in the preoptic and anterior hypothalamic region, a more numerous group of immunoreactive perikarya was located along the walls of third ventricle in these same regions, and, finally, a few scattered cells were found in a more lateral position on both the internal and external sides of the tip of the fasciculus prosencephali lateralis. The periventricular cell population extended in the caudal direction unti the posterior hypothalamus. Labelled fibers were always associated with these immunoreactive perikarya, and they were also found in the adjacent hypothalamic regions. A dense innervation of the median eminence was also detected. These data are compared with previous studies in mammals and birds that had identified more restricted populations of immunoreactive cells and the possible sources of the observed discrepancy are discussed. The functional significance of the present data is also

ISSN:0092-7317    

DOI:10.1002/cne.903500305

出版商:Wiley‐Liss, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractStudies employing axoplasmic transport techniques have suggested that the central arbors of vibrissae‐related primary afferents are rapidly and permanently lost from the trigeminal (V) brainstem complex after transection of the intraorbital nerve (ION). The present study reexamined this issue using immunocytochemistry for galanin (GAL) and anterograde labelling with Di‐I to evaluate V brainstem organization in rats that sustained damage to the ION or individual vibrissae follicles in infancy or adulthood. After adult nerve damage, GAL‐positive fibers are increased in layers I and II of V subnucleus caudalis (SpC). This was apparent by 3 days after the lesion. In rats that sustained nerve damage at birth (PO), GAL immunoreactivity (IR) appeared throughout the V brainstem complex and had a patchy distribution similar to that of vibrissae‐related V primary afferents in normal rats. Increased GAL‐IR in rostral portions of the V brainstem complex was observed in rats that sustained ION damage as late as P14. Additional experiments in which nerve damage was followed by destruction of the V ganglion demonstrated that this GAL‐IR was contained in primary afferents. Damage to single vibrissa follicles or to a row of follicles produced a single patch or row of GAL‐IR terminals in the somatotopically appropriate portion of the ipsilateral V brainstem complex. Di‐I labelling in neonatally nerve‐damaged rats demonstrated that primary afferent axons filled the central territory normally innervated by this nerve and that their terminal distribution was patchy. These results suggest that the V ganglion cells that survive neonatal axotomy may retain somatotopically organized projections to the V brainstem complex for at least a limited

ISSN:0092-7317    

DOI:10.1002/cne.903500306

出版商:Wiley‐Liss, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe μ, δ, and κ opioid receptors are the three main types of opioid receptors round in the central nervous system (CNS) and periphery. These receptors and the peptides with which they interact are important in a number of physiological functions, including analgesia, respiration, and hormonal regulation. This study examines the expression of μ, δ, and κ receptor mRNAs in the rat brain and spinal cord using in situ hybridization techniques. Tissue sections were hybridized with35S‐labeled cRNA probes to the rat μ (744–1, 064 b), δ (304–1,287 b), and κ (1,351–2,124 b) receptors. Each mRNA demonstrates a distinct anatomical distribution that corresponds well to known receptor binding distributions. Cells expressing μ receptor mRNA are localized in such regions as the olfactory bulb, caudate‐putamen, nucleus accumbens, lateral and medial septum, diagonal band of Broca, bed nucleus of the stria terminalis, most thalamic nuclei, hippocampus, amygdala, medial preoptic area, superior and inferior colliculi, central gray, dorsal and median raphe, raphe magnus, locus coeruleus, parabrachial nucleus, pontine and medullary reticular nuclei, nucleus ambiguus, nucleus of the solitary tract, nucleus gracilis and cuneatus, dorsal motor nucleus of vagus, spinal cord, and dorsal root ganglia. Cellular localization of δ receptor mRNA varied from μ or κ, with expression in such regions as the olfactory bulb, allo‐ and neocortex, caudate‐putamen, nucleus accumbens, olfactory tubercle, ventromedial hypothalamus, hippocampus, amygdala, red nucleus, pontine nuclei, reticulotegmental nucleus, motor and spinal trigeminal, linear nucleus of the medulla, lateral reticular nucleus, spinal cord, and dorsal root ganglia. Cells expressing, κ receptor mRNA demonstrate a third pattern of expression, with cells localized in regions such as the claustrum, endopiriform nucleus, nucleus accumbens, olfactory tubercle, medial preoptic area, bed nucleus of the stria terminalis, amygdala, most hypothalamic nuclei, median eminence, infundibulum, substantia nigra, ventral tegmental area, raphe nuclei, paratrigeminal and spinal trigeminal, nucleus of the solitary tract, spinal cord, and dorsal root ganglia. These findings are discussed in relation to the physiologica functions associate

ISSN:0092-7317    

DOI:10.1002/cne.903500307

出版商:Wiley‐Liss, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe aim of this study has been to determine the neuronal types (pyramidal and nonpyramidal) within the rat's visual cortex, which project through the corpus callosum. To this end, the morphology and laminar distribution of callosal cells have been investigated by combining Diamidino Yellow retrograde tracing with intracellular injection of Lucifer Yellow in slightly fixed tissue slices.The visual callosal projection arises from pyramidal cells of diverse morphology in layers II to VIb, as well as from several modified pyramids located mainly in layers II, IV (star pyramids) and VIb (horizontal or inverted pyramids and related forms of spiny stellate cells). Our results indicate that in rats, as in other mammals, several types of nonpyramidal neurons also contribute to the contralateral projection. Bitufted cells in layers II–III and V were found to project contralaterally. Moreover, a spine‐free layer V cell and a sparsely spiny multipolar neuron of layer IV were also labeled. In both stellate cells, partial axonal labeling reveals that these callosal cells display a local axonal arborization. Finally, our results of retrograde transport with Diamidino Yellow and with another sensitive retrograde tracer, the beta subunit of the cholera toxin, demonstrate for the first time that the two main neuronal types of layer I participate in the callosal projection. In layer I, several small horizontal cells of the inner half of layer I and a large subpial cell displaying long radiating dendrites were also injected. The latter cell may correspond to the Cajal‐Retzius cell of the adult rat.In spite of the important differences in the organization of the visual system between rodents and cats, the callosal projection in both mammals is composed of a large variety of pyramidal cells and several nonpyramidal neurons. This high morphological diversity suggests that the callosal projection is much more physiologically complex than the extracortical efferents of the visual cortex, resembling other cortico‐cortical connections. The roles that the different callosal cells may play in the processing of visual information are discussed in relation to the known functions of the corpus c

ISSN:0092-7317    

DOI:10.1002/cne.903500308

出版商:Wiley‐Liss, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractThe adult goldfish retina and optic nerve display continuous growth, plasticity, and the capacity to regenerate throughout the animal's life. The intermediate filament proteins in this pathway are different from those in adult mammalian nerves, which do not continuously grow or normally regenerate. One novel intermediate filament protein of the goldfish visual pathway is plasticin, which is synthesized in ganglion cells and transported into the optic nerve. Using specific polyclonal antibodies raised against a plasticin fusion protein, we investigated the distribution of this protein in the normal retina and nerve and in the retina and nerve following optic nerve crush. In the normal pathway, plasticin was localized predominantly to the axons of very young ganglion cells; however, there was considerable immunoreactivity in older axons as they approach the chiasm. In addition, following optic nerve crush, all ganglion cell somata and their axons proximal to the crush site became equally immunoreactive. The results suggest that plasticin may contribute to axonal growth, plasticity, and regeneration. © 1994 Wiley‐Liss, I

ISSN:0092-7317    

DOI:10.1002/cne.903500309

出版商:Wiley‐Liss, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractMorphological and physiological characteristics of the two major motor axons supplying the commonly studied ventral longitudinal muscle fibers (6 and 7) of third‐instarDrosophila melanogasterlarvae were investigated. The innervating terminals of the two motor axons differ in the size of their synapse‐bearing varicosities. The terminal with the larger varicosities also fluoresces more brightly when stained with the vital fluorescent dye 4‐(4‐diethylaminotyryl)‐N‐methylpyridinium iodide (4‐Di‐2‐Asp) and occupies a larger total contact area on the muscle fiber. Through selective simultaneous recording of synaptic currents from identified boutons in living preparations during elicitation of synaptic potentials, it was shown that the axon with the smaller varicosities generates a large excitatory junction potential (EJP) in muscle 6 and that the axon with the larger varicosities generates a smaller EJP. Short‐term facilitation is more pronounced for the smaller EJP. In preparations treated with 4‐Di‐2‐Asp, the fluorescence of smaller varicosities increases with stimulation that elicits the large EJPs, indicating an acitivity‐dependent entry of calcium that enhances mitochondrial fluorescence. The differences in morphology and physiology of the two axons are similar to, though less pronounced than, those observed in „phasic”︁ and „tonic”︁ motor axon

ISSN:0092-7317    

DOI:10.1002/cne.903500310

出版商:Wiley‐Liss, Inc.    

年代:1994

数据来源: WILEY

摘要:

AbstractImmunohistochemistry was used in this study to evaluate the effects of retinal lesions upon the distribution of neuronal nicotinic acetylocholine receptor subunits in the chick visual system. Following unilateral retinal lesions, the neuropil staining with an antibody against the β2 receptor subunit, a major component of α‐bungarotoxin‐insensitive nicotinic receptors, was dramatically reduced or completely eliminated in all of the contralateral retinorecipient structures. On the other hand, neuropil staining with antibodies against two α‐bungarotoxinsensitive receptor subunits, α7 and α8, was only slightly affected after retinal lesions. Decreased neuropil staining for α7‐like immunoreactivity was only observed in the nucleus of the basal optic root and layers 2–4 and 7 of the optic tectum. For α8‐like immunoreactivity, slight reduction of neuropil staining could be observed in the ventral geniculate complex, griseum tecti, nucleus lateralis anterior, nucleus lentiformis mesencephali, layers 4 and 7 of the tectum, and nucleus suprachiasmaticus. Taken together with previous data on the localization of nicotinic receptors in the retina, the present results indicate that the β2 subunit is transported from retinal ganglion cells to their central targets, whereas the α7 and α8 subunit immunoreactivity appears to have a central origin. The source of these immunoreactivities could be, at least in part, the stained perikarya that were observed to contain α7 and α8 subunits in all retinoreceipient areas. In agreement with this hypothesis, the β2 subunit of the nicotinic acetylcholine receptors was not frequently found in perikarya of the same areas

ISSN:0092-7317    

DOI:10.1002/cne.903500311

出版商:Wiley‐Liss, Inc.    

年代:1994

数据来源: WILEY