摘要:

AbstractThe purpose of the study was to determine the morphology and distribution of vasoactive intestinal polypeptide‐ and peptide histidine isoleucineimmunoreactive (VIP‐ and PHI‐ir) neurons and innervation patterns in the main and accessory olfactory bulb, anterior olfactory nucleus, and piriform cortex of the adult cat. In these centers, VIP‐ and PHI‐immunoreactive material are present in the same neuronal types, respectively, therefore summarized as VIP/PHI‐ir neurons. In the main olfactory bulb, the majority of VIP/PHI‐ir neurons are localized in the external plexiform layer. These neurons give rise to two or more locally branching axons. They form boutons on mitral and external tufted cell bodies. According to the morphology and location, we have classified these neurons asVan Gehuchtencells. Some VIP/PHI‐ir neurons are present in the glomerular layer. They have small somata and give rise to dendrites branching exclusively into glomeruli. We have classified these neurons asperiglomerular cells. In the granule cell layer, neurons with long apical dendrites and one locally projecting axon are present. In the accessory olfactory bulb, VIP/PHI‐ir neurons are localized in the mixed external/mitral/internal plexiform layer. They representVan Gehuchtencells.In the anterior olfactory nucleus and piriform cortex, VIP/PHI‐irbipolar basket neuronsare present. They are localized mainly in layers II/III. These neurons are characterized by a bipolar dendritic pattern and by locally projecting axons forming basket terminals on large immunonegative cell somata. Because of their common morphological features, we summarize them as the retrobulbar VIP/PHI‐ir interneuron population.The PHI‐ir neurons display the same morphology as the VIP‐ir cells. However, they are significantly lower in number with a ratio of VIP‐ir to PHI‐ir cells about 2:1 in the main and accessory olfactory bulb and in the anterior olfactory nucleus. By contrast, in the piriform

ISSN:0092-7317    

DOI:10.1002/cne.902940302

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

年代:1990

数据来源: WILEY

摘要:

AbstractHuman placental antigen X‐P2(hPAX‐P2), an antigen complex associated with cytochrome P‐450 of aromatase within estrogen synthesizing tissues, has been reported to be present in a distinct group of rat primary olfactory receptors involved in suckling behavior. In this study, most of the mitral and tufted cells in the rat olfactory bulb were found to possess hPAX‐P2immunoreactivity. This suggests that the activity of these cells can be hormonally modulated and that hPAX‐P2is involved in rat olfaction not only at the receptor level but also at integrative brain levels via the secondary projecting neurons of the olfactor

ISSN:0092-7317    

DOI:10.1002/cne.902940303

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

年代:1990

数据来源: WILEY

摘要:

AbstractAntisera raised against the monoamines serotonin (5‐HT) and noradrenaline (NA) were employed in a study designed to provide a detailed description of the distribution, morphology, and synaptic organization of the serotoninergic and noradrenergic afferents in the lateral geniculate nucleus (LGN) of the rat. The distribution patterns of the two types of immunoreactive fibers were distinct and largely complementary to each other. NA axons were particularly concentrated in the dorsal lateral geniculate nucleus (LGd), with the ventral lateral geniculate nucleus (LGv) and the intergeniculate leaflet (IGL) receiving substantially fewer fibers. In contrast, 5‐HT axons, although present throughout the LGN, were preferentially concentrated in the LGv and IGL.5‐HT and NA axon terminals and axonal varicosities, examined in single and serial ultrathin sections, formed conventional synapses in the extraglomerular neuropil. The types of synapses and the nature of the postsynaptic targets were different for the two monoamines. 5‐HT afferents formed asymmetrical synapses on dendritic spines and shafts of both presumptive relay cells and interneurons but established symmetrical synapses on cell bodies. However, NA afferents formed almost exclusively symmetrical synapses on dendritic spines and shafts and made no contacts with cell bodies.The present findings suggest that the 5‐HT and NA afferents of the rat LGN, which are likely to influence certain stages of visual processing, exhibit distinct organizational principles and act at restriced sites as do other classical neurotransmitte

ISSN:0092-7317    

DOI:10.1002/cne.902940304

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

年代:1990

数据来源: WILEY

摘要:

AbstractIn the present study, immunocytochemistry with an antiserum against dopamine (DA) revealed hitherto unknown terminal fields of DA axons in the lateral geniculate nucleus (LGN) of the rat. The innervation of all subdivisions of the LGN is achieved by a common set of afferent fibers that branch to form terminal fields of uneven density. The ventral lateral geniculate nucleus (LGv) receives slightly more DA axons than the dorsal lateral geniculate nucleus (LGd), whereas within the latter, DA afferents innervate the lateral part of the nucleus slightly more densely. Labeled axon terminals and varicosities, examined in single and serial ultrathin sections, were found in the extraglomerular neuropil in the LGd and in the neuropil of the LGv characterized by relatively simple synaptic relationships. They formed predominantly asymmetrical synaptic contacts with dendritic profiles. Occasionally, the postsynaptic elements were found to be presynaptic dendrites of presumptive interneurons. Some of the possible roles of this newly demonstrated DA afferent system in the physiology of the LGN and in the pathophysiology of diseases associated with impairment of dopaminergic activity are discussed.

ISSN:0092-7317    

DOI:10.1002/cne.902940305

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

年代:1990

数据来源: WILEY

摘要:

AbstractAn immunocytochemical method was used for localization of various peptide‐like substances in theAscarisnervous system. Out of 45 antipeptide antisera, 12 demonstrated immunoreactivity in different subsets of neurons; these 12 antisera were raised against luteinizing hormone‐releasing hormone (LHRH),Aplysiapeptide L11 (L11),Aplysiapeptide 12B(12B), small cardioactive peptide B (SCPB), neuropeptide Y (NPY), FMRFamide, gastrin‐17, cholecystokinin octapeptide (CCK‐8), α‐melanocyte stimulating hormone (α;MSH), calcitonin gene related peptide (CGRP), corticotropin releasing factor (CRF), and vasoactive intestinal peptide (VIP). Several peptide‐like substances were colocalized to the same neuron. Our results suggest thatAscaris, like other organisms, contains multiple peptid

ISSN:0092-7317    

DOI:10.1002/cne.902940306

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

年代:1990

数据来源: WILEY

摘要:

AbstractDendritic morphology and development in the medial superior olivary nucleus of the ferret were studied using the Golgi method. In the adult ferret most medial superior olivary neurons had disk‐shaped dendritic fields. These dendritic fields were oriented such that cells in a coronal plane of section appeared bipolar with major lateral and medial dendritic axes. In the horizontal plane the dendrites radiated about the soma. Dendrites of principal cells branched distally into tufts of numerous, tertiary processes that were beaded and thin. Peripheral cells in the fiber mantle encircling the nucleus were generally spindle‐shaped or tripolar and lacked the tufted dendrites of principal cells. The dendrites of these peripheral cells coursed parallel to the nucleus both dorsoventrally and rostrocaudally. Horizontally oriented dendrites were observed even at birth for some cells in the medial superior olivary nucleus and bipolar dendritic fields were typical of most cells by the end of the second postnatal week. Dendrites of immature cells varied in caliber and radiated in all directions from the soma. Around postnatal days 8‐10 transient appendages appeared on the soma and dendrites, first proximally and then more distally. These appendages persisted until the first postnatal month. Cell size and dendritic radius increased markedly during this same period. Postnatal days 28‐30 were marked by the first appearance of tufts of tertiary dendritic branches. The tendril‐like processes continued to increase in length until about the end of the second postna

ISSN:0092-7317    

DOI:10.1002/cne.902940307

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe ultrastructure of the medial superior olive (MSO) was studied in the adult ferret. The synaptic terminals were categorized on the basis of morphology and their distribution determined. There are three types of synaptic terminals: R terminals, containing round vesicles; Ov terminals, containing ovoid vesicles; and P terminals, containing vesicles of varying morphologies. R terminals are the dominant terminal type on both the somata and dendrites. Ov and P terminals are equally prevalent on the dendrites; however, P terminals are significantly more common than Ov terminals on the somata. Furthermore, P terminals are significantly more common on the somata than on the dendrites. These results suggest that there is some segregation of types of afferent synapses on MSO cells.

ISSN:0092-7317    

DOI:10.1002/cne.902940308

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

年代:1990

数据来源: WILEY

摘要:

AbstractThe intent of our study was to determine when catecholaminergic axons grow into each of their adult targets in the spinal cord of the North American opossum (Didelphis virginiana) and to identify the origin of catecholaminergic axons in the lumbosacral cord at different stages of development. Tyrosine hydroxylase‐like immunoreactive axons, presumed to be catecholaminergic, were demonstrated at different stages of development by the indirect antibody peroxidase‐antiperoxidase technique of Sternberger. The neurons giving rise to such axons in the lumbosacral cord were identified by using the retrograde transport of Fast Blue and immunofluorescence for tyrosine hydroxylase‐like immunoreactive neurons.At birth, 12‐13 days after conception, tyrosine hydroxylase‐like immunoreactive axons are present in the marginal zone throughout the length of the spinal cord. Such axons are particularly numerous in the dorsolateral marginal zone, the region containing most of them in adult animals. By postnatal day 3, a few immunoreactive axons are present in the intermediate (mantle) zone of the spinal cord; and by postnatal day 8, they are most concentrated in the presumptive intermediolateral cell column. Laminae I and II of the dorsal horn are not innervated by such axons until approximately postnatal day 15. By postnatal day 44, the distribution of tyrosine hydroxylase‐like immunoreactive axons in the spinal cord resembles that in adult animals, although some areas may be hyperinnervated.At birth, tyrosine hydroxylase‐like immunoreactive cell bodies are present in all of the brainstem areas providing catecholaminergic projections to the spinal cord in adult animals (Pindzola et al.:Brain Behav. Evol. 32:281‐292,'88); and by at least postnatal day 5, lumbosacral injections of Fast Blue retrogradely label tyrosine hydroxylase‐like immunoreactive neurons in all such areas. Retrogradely labeled immunoreactive neurons were also found in areas that do not contain them in adult animals. Such areas include the dorsal part of the nucleus coeruleus and certain areas of the reticular formation. During development, spinally projecting tyrosine hydroxylase‐like immunoreactive neurons are numerous medial to the nucleus ventralis lemnisci lateralis (the paralemniscal region), whereas only a few are present in the same location in adult animals. Our results suggest that catecholaminergic axons grow into the spinal cord prenatally, that they innervate their adult targets postnatally and over an extended time period, and that during some stages of development they originate from areas that do not supply them

ISSN:0092-7317    

DOI:10.1002/cne.902940309

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

年代:1990

数据来源: WILEY

摘要:

AbstractWe have studied the position and numbers of retinopetal axons in the rainbow cichlid fish,Herotilapia multispinosa, to determine the response of related parts of the brain of fish to the continual addition of new neurons in the retina. The retinopetal axons were traced by using the retrograde tracers HRP and cobaltous lysine and an immunocytochemical probe, antibodies to FMRFamide, the molluscan cardioexcitatory peptide. One population of cells with retinopetal axons was found in the telencephalon (in the nucleus olfactoretinalis) and the other was scattered in the diencephalon. Some of the cells in the nucleus olfactoretinalis with retinopetal axons were FMRFamide positive; antibodies were used to trace the axons of these cells into the retina. All the retinopetal axons, from the nucleus olfactoretinalis and the diencephalon, were confined to the portion of the optic nerve that contains axons from the central retinal ganglion cells, that is, the oldest ganglion cells. Theis result suggests that the retinopetal axons grow into the optic nerve and retina early in the life of the fish, and no new ones are added later in life despite the extensive addition of cells in the retina. Counts of the cells in the nucleus olfactoretinalis that project to the retina in 3‐month‐old and adult fish support this interpretation. We conclude that retinopetal axons grow into the retina early in the life of the fish and respond to the formation of new retina by extending their arbors toward the new ret

ISSN:0092-7317    

DOI:10.1002/cne.902940310

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

年代:1990

数据来源: WILEY

摘要:

AbstractThis paper reports a study of the development of cells that project to the retina from the telencephalic nucleus olfactoretinalis and the diencephalon. Stell et al. (Proc. Natl. Acad. Sci. USA 81:940‐944,'84) have shown that the FMRFamide‐immunoreactive (FMRFamide‐ir) cells in the nucleus olfactoretinalis project to the retina. Therefore, we used immunocytochemistry to study the development of these cells in the nucleus olfactoretinalis. Twenty hours after fry hatched, FMRFamide‐ir cells were unambiguously seen in the nucleus olfactoretinalis. At this time the axons of these cells could be traced into the optic nerve. A few hours later the axons were visible in the retina and soon attained their adult position in the inner plexiform layer near the amacrine cells.In older fry, tracers were used to fill retinopetal cells in both the nucleus olfactoretinalis and the diencephalon. Counts of these cells demonstrated that over one‐third of the adult number of retinopetal cells in the nucleus olfactoretinalis are present and have axons in the retina when the fry is 9 days old, and the percentage grows to one‐half by the time the fry is 1 month old. Development of the retinopetal cells in the diencephalon lags behind that of the cells in the nucleus olfactoretinalis. However, about one‐third of the adult number extend their axons into the optic nerve by 1 month of age.These results support our suggestion that the retinopetal cells have axons in the old part of the optic nerve because these cells were born and extended axons early in the lif

ISSN:0092-7317    

DOI:10.1002/cne.902940311

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

年代:1990

数据来源: WILEY