摘要:

AbstractThe presence of galanin‐like substances and their relation to substance P‐, vasotocin‐, and isotocin‐immunoreactive neurons and fibers in the brain of teleosts was investigated with immunohistochemical methods. Two specific antisera against synthetic porcine galanin (GAL) revealed cell bodies and fibers in the brain of four different teleost species (Salmo salar, Carassius carassius, Gasterosteus aculeatus, and Anguilla anguilla). In all four species the main location of galanin immunoreactivity was in the hypothalamo‐pituitary region. A detailed study of the distribution of galanin immunoreactivity inS. salarshowed that galanin immunoreactive (GALir) perikarya were present in the nucleus preopticus periventricularis, an area that may be compared to the supraoptic nucleus in mammals, and in the nucleus lateralis tuberis, a nucleus involved in pituitary control in fishes that may be compared with the arcuate nucleus in mammals, GALir perikarya were found also in the nucleus recessus lateralis and in the nucleus recessus posterior. Numerous GALir fibers were present in the telencephalon and diencephalon, whereas only small numbers of fibers were found in the brainstem. In contrast to the situation in mammals, no GALir perikarya were observed in the brainstem areas corresponding to the noradrenergic locus coeruleus and serotonergic raphe nuclei inS. salar.We did not find any coexistence of GALir substances with arginine vasotocin or isotocin in neurosecretory neurons, as has been shown for galanin with the mammalian counterparts vasopressin and oxytocin. Also, the galanin‐like substance(s) and their structurally closest related peptide family, the tachykinins, belong to separate neuronal systems in teleosts. The presence of GALir neurons in brain areas known to be involved in pituitary control, and a massive GALir innervation of the pituitary, strongly indicate a role for galanin‐like substances in pituitary control also in teleosts. Furthermore, the presence of extrahypothalamic GALir fibers suggests involvement of galanin‐like substances in other brain functions in teleosts. In conclusion, there are general similarities between teleosts and mammals concerning the distribution of galanin‐like substances. However, there seem to be substantial differences in their distribution relative to functionally related peptides within the hypothalamo‐pituitary system. Whereas galanin appears to be colocalized and released together with vasopressin and oxytocin in mammals, in teleosts the homologous substances are contained within different sets of neurons that innervate the same ta

ISSN:0092-7317    

DOI:10.1002/cne.903060302

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe presence of reduced nicotinamide adenine dinucleotide phosphate (NADPH)‐diaphorase activity was studied histochemically in the sensory ganglia of the rat. Supraspinally, the trigeminal ganglion possessed only a few cells positively stained for NADPH‐diaphorase, while a large number of positive neurons was found in the nodose ganglion. In the dorsal root ganglia, the distribution of positive cells showed a peculiar pattern in relation to spinal levels. Very minor populations (less than 2% of the total ganglionic cells) exhibited positive reaction in ganglia at levels ranging from the first cervical (C1) to fourth thoracic (T4) and from the second lumber (L2) through the entire sacral levels. In the middle to lower thoracic levels (from T5 to L1), however, abundant diaphorase‐positive cells were observed. From these positive neurons it was possible to trace intensely stained nerve fibers. In the lower thoracic level, for example, dense positive fibers were seen in the ramus communicans. Retrograde tracing studies revealed that diaphorase‐containing neurons in the lower thoracic level project at least partly to the gastric wall and the celiac ganglion. These results indicate that the diaphorase‐positive ganglionic neurons in the thoracicolumbar levels may carry autonomic visceral afferent information. Double staining with NADPH‐diaphorase histochemistry and peptide immunohistochemistry revealed that NADPH‐diaphorase colocalizes with calcitonin gene‐related peptide and substance P in many of these visceral a

ISSN:0092-7317    

DOI:10.1002/cne.903060303

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe spiral ganglia of the cat, gerbil, mouse, rat, and human were immunohistochemically stained with various monoclonal neurofilament antibodies. Three antibodies to the 200‐kD neurofilament protein (R‐3, Dräger et al., '84; ICN anti‐200, clone NE14, Debus et al., '83; RT‐97, Wood and Anderton, '81) labeled the somata of type II spiral ganglion neurons but not those of type I ganglion neurons. In the extreme base of the cochlea of cats, mice and rats, there was intense labeling of a few (<0.5% of the total ganglion population) large neurons resembling type I ganglion neurons.Several other neurofilament antibodies (Amtersham anti‐68, Amersham and ICN anti‐160, and SMI‐32) did not specifically label type II ganglion neurons but instead labeled all neurons of the spiral ganglion. These two patterns of labeling prompted us to investigate the cause for this difference. Because antibodies against the 200‐kD neurofilament protein preferentially labeled type II neurons and because 200‐kD neurofilament is highly phosphorylated, we treated cochlear tissue with alkaline phosphatase in order to remove phosphate groups. This treatment eliminated the intense labeling of type II neurons with R‐3, ICN anti‐200, and RT‐97, but had no effect on the intense labeling of ganglion cell bodies observed with the other neurofilament antibodies tested. This evidence suggests that labeling occurs because of the cytoplasmic presence of phosphorylated 200‐kD neurofilament protein in type II ganglion neurons. Populations of neurons may thus differ in their neurofilament epitopes and monoclonal antibodies can be use

ISSN:0092-7317    

DOI:10.1002/cne.903060304

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

年代:1991

数据来源: WILEY

摘要:

AbstractLarval sea lampreys recover from complete spinal transection by a process involving directionally specific axonal regeneration. In order to determine whether this is also true of adults, 14 adult lampreys were transected at the level of the 5th gill and allowed to recover for 10 weeks. Müller and Mauthner cells and their giant reticulospinal axons (GRAs) were impaled with microelectrodes and injected with horseradish peroxidase (HRR) The tissue was processed for HRP histochemistry and wholemounts of brain and spinal cord were prepared.All animals recovered coordinated swimming; 61 of 121 (50%) neurites emanating from 30 axons regenerated caudal to the scar into the distal stump. Of the neurites which had grown beyond the scar, 92% were correctly oriented, i.e., caudalward and ipsilateral to the parent axon. Retransection in two additional animals eliminated the recovered swimming. Thus, behavioral recovery in adult sea lampreys is accompanied by directionally specific axonal regeneration

ISSN:0092-7317    

DOI:10.1002/cne.903060305

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

年代:1991

数据来源: WILEY

摘要:

AbstractVirtually all of the SCPB‐like immunoreactive neurons (ca. 60 cells) in the lobsterHomarus americanusalso contain FMRFamide‐like immunoreactivity. Control experiments reveal that SCPB‐and FMRFamide‐like immunoreactivities are successfully preadsorbed with their specific antigens, while the normal staining pattern is retained following preadsorption of each antibody with the alternate peptide. These experiments potentially lead to the conclusion that the anti‐SCPBand anti‐FMRFamide antibodies are labeling distinct compounds that are colocalized in lobster neurons.The lobster nervous system does not, however, contain authentic FMRFamide, but rather several FMRFamide‐like compounds (Trimmer et al., J. Comp. Neurol. 266:16–26, 1987). The most abundant of these is the octapeptide TNRNFLRFamide. Experiments demonstrate that SCPB‐like immunoreactivity is completely preadsorbed with synthetic TNRNFLRFamide, while there is a significant or complete loss of staining after preadsorption of the FMRFamide antibody with this molecule. Met‐enkephalin‐Arg‐Phe‐amide (YGGFMRFamide), an extended opioid peptide containing the FMRFamide sequence, also preadsorbs SCPB‐and FMRFamide‐like immunoreactivities, while Met‐enkephalin‐Arg‐Phe (YGGFMRF) has no effect on the staining properties of these antibodies. These results suggest that the SCPBantibody can bind to extended forms of FMRFamide‐like molecules, and that anti‐SCPB. and anti‐FMRFamide antibodies may be colabeling one or more FM

ISSN:0092-7317    

DOI:10.1002/cne.903060306

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

年代:1991

数据来源: WILEY

摘要:

AbstractThis study used neuroanatomical techniques to investigate sources of afferents to the Edinger‐Westphal nucleus (EW) of the pigeon. The EW contains the parasympathetic preganglionic neurons that, by way of the oculomotor nerve, project to the ciliary ganglion (Narayanan and Narayanan, '76; Lyman and Mugnaini, '80). The ciliary ganglion, in turn, innervates the internal musculature of the eye; the ciliary body, the iris sphincter muscle, and the smooth muscle of choroidal blood vessels (Marwitt et al., '71; Pilar and Tuttle, '82), In the bird, the neurons in the ciliary ganglion that innervate the iris sphincter muscle and the ciliary body receive input specifically from cells in the lateral EW (EWl), whereas those that innervate choroidal blood vessels receive input from cells in the medial EW (EWm) (Reiner et al., '83). Thus neurons in the EWl mediate pupilloconstriction and accommodation, whereas neurons in the EWm modulate choroidal blood flow.To study the afferents to EW, injections of horseradish peroxidase (HRP) were placed in this nucleus. These injections resulted in labeled cells in the area pretectalis, a retinorecipient pretectal nucleus and the suprachiasmatic nucleus, a retinorecipient hypothalamic nucleus. We have previously identified both these areas as being sources of afferents to EW (Gamlin et al., '82, '84). In addition, these HRP injections into EW resulted in labeled cells in the medial mesencephalic reticular formation (MRF) lateral and ventral to the oculomotor nucleus and in a localized area of the rostral lateral mesencephalic reticular formation (LRF) dorsolateral to nucleus subpretectalis. Injections of tritiated amino acids into the MRF labeled the entire EW, while such injections into the LRF labeled only the lateral EW. Both of these projections were predominantly contralateral.This study has identified the sources of two previously undocumented inputs to the avian EW. Both sources of input, the MRF and rostral LRF, receive afferents from visuomotor areas of the telencephalon and visual structures in the midbrain. The MRF input to EW could have either direct or modulatory influences on pupil diameter, accommodation, and choroidal blood flow, The LRF input to EW could play a role in controlling accommodation and possibly the pupillary near respons

ISSN:0092-7317    

DOI:10.1002/cne.903060307

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

年代:1991

数据来源: WILEY

摘要:

AbstractIt has been proposed that nerve growth factor (NGF) provides critical trophic support for the cholinergic neurons of the basal forebrain and that it becomes available to these neurons by retrograde transport from distant forebrain targets. However, neurochemical studies have detected low levels of NGF mRNA within basal forebrain areas of normal and experimental animals, thus suggesting that some NGF synthesis may actually occur within the region of the responsive cholinergic cells. In the present study with in situ hybridization and immunohistochemical techniques, the distribution of cells containing NGF mRNA within basal forebrain was compared with the distribution of cholinergic perikarya. The localization of NGF mRNA was examined by using a35S‐labeled RNA probe complementary to rat preproNGF mRNA and emulsion autoradiography. Hybridization of the NGF cRNA labeled a large number of cells within the anterior olfactory nucleus and the piriform cortex as well as neurons in a continuous zone spanning the lateral aspects of both the horizontal limb of the diagonal band of Broca and the magnocellular preoptic nucleus. In the latter regions, large autoradiographic grain clusters labeled relatively large Nissl‐pale nuclei; it did not appear that glial cells were autoradiographically labeled. Comparison of adjacent tissue sections processed for in situ hybridization to NGF mRNA and immunohistochemical localization of choline acetyltransferase (ChAT) demonstrated overlapping fields of cRNA‐labeled neurons and ChAT‐immunoreactive perikarya in both the horizontal limb of the diagonal band and magnocellular preoptic regions. However, no hybridization of the cRNA probe was observed in other principal cholinergic regions including the medial septum, the vertical limb of the diagonal band, or the nucleus basalis of Meynert. These results provide evidence for the synthesis of NGF mRNA by neurons within select fields of NGF‐responsive cholinergic cells and suggest that the generally accepted view of “distant” target‐derived neurotrophic support should be reconsidere

ISSN:0092-7317    

DOI:10.1002/cne.903060308

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

年代:1991

数据来源: WILEY

摘要:

AbstractElectrophysiological recording, together with anterograde and retrograde axonal tracers, was used to provide a comprehensive description of the origin and distribution of the olfactory input to the lateral hypothalamus. This input was much more substantial to the caudal part of the hypothalamus than to the rostral part and originates from several different areas of the olfactory cortex.Positive responses to electrical stimulation of the olfactory bulb were found consistently in the postero‐lateral hypothalamus, but only occasionally at more rostral levels. In agreement with this, injections of wheat germ agglutinin conjugated to horseradish peroxidase (WGA‐HRP) in the posterior half of the lateral hypothalamus labeled cells in four cortical areas that receive input from the olfactory bulb: the anterior olfactory nucleus, the piriform cortex (in the deepest layer or ventral endopiriform nucleus), the olfactory tubercle (in the deep polymorphic layer), and the anterior cortical nucleus of the amygdala. Injections of WGA‐HRP in the anterolateral hypothalamus labeled cells only in the anterior cortical nucleus of the amygdala.Anterograde axonal tracing confirmed these projections. Injections of3H‐leucine in the anterior olfactory nucleus, the piriform cortex, and the olfactory tubercle produced axonal label that was light and confined to the medial forebrain bundle in the rostral hypothalamus but was more substantial and extended throughout the lateral hypothalamic area caudally. Injections in the anterior cortical amygdaloid nucleus labeled axons in the anterior hypothalamus and in the premammillary nuclei as well as in the posterolateral hypothalamic area. In addition, a projection was demonstrated to the nuclei gemini from the polymorphic zone deep to the olfactory tubercle.Injections of two fluorescent retrograde tracers into the mediodorsal nucleus of the thalamus and the posterolateral hypothalamus showed that cells projecting to both diencephalic sites were intermingled in all of the olfactory cortical areas except the anterior olfactory nucleus, where cells were labeled only from the hypothalamus. In the deep layer of the piriform cortex and in the anterior cortical amygdaloid nucleus cells were also double labeled, indicating that they send collateral axons to both parts of the dienc

ISSN:0092-7317    

DOI:10.1002/cne.903060309

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

年代:1991

数据来源: WILEY

摘要:

AbstractThe heterogeneous hypothalamic paraventricular nucleus (PVN) is intimately involved in the regulation of several homeostatic functions. These regulations might, at least partly, be mediated via neuronal projections from the PVN to circumventricular organs outside the blood‐brain barrier. To study the efferent projections of the medial and periventricular parvicellular subnuclei of the PVN with particular emphasis on the projections to the circumventricular organs, anterograde tracing withPhaseolus vulgarisleucoagglutinin (PHA‐L) was applied. Three major efferent pathways and one minor one coursed from the medial and periventricular parvicellular subnuclei to the circumventricular organs. The major fiber projections included a rostral, a lateral, and a dorsocaudal projection tract, whereas the minor projection coursed ventrally. Fibers of the rostral projection were followed to the preoptic area and along the fornix to the subfornical organ. Single fibers originating from this projection coursed further rostrally to the organum vasculosum laminae terminalis. The lateral projection equivalent to the hypothalamo‐pituitary tract passed through the lateral hypothalamic area to the median eminence, and nerve terminals were observed throughout the rostrocaudal extent of this structure. A few fibers of this bundle continued into the infundibular stalk and some terminated in the posterior pituitary lobe. Few fibers of the lateral projection descended to caudal pontine levels, where they reached descending fibers of the dorsocaudal projection. The dorsocaudal projection was essentially restricted to midline structures. Along the midline, fibers were followed from the hypothalamus either dorsally through the thalamus to the dorsal part of the third ventricle or caudally alongside the ventricular wall to the mesencephalic periaqueductal grey. The density of fibers decreased along the caudal direction of the neuraxis. The dorsal part of this projection gave rise to terminals in the deep pineal gland and pineal stalk, whereas the caudal part of this projection sent terminating fibers into the area postrema. The minor ventrally directed projection could be followed through the periventricular region to the rostral part of the median eminence.The number of terminals in the circumventricular organs varied. Within the median eminence, a high density of afferents was observed in the entire rostrocaudal extent of the external zone, whereas a low density of fibers was seen in the internal zone. A medium density of afferents was observed in the organum vasculosum laminae terminalis, whereas a relative low density of nerve terminals was observed in the posterior pituitary, the deep pineal gland, the subfornical organ, and the area postrema. The morphology of the PHA‐L immunoreactive nerve fibers and terminals in these organs suggests that specific PVN subnuclei, in addition to a neurosecretory release to the blood stream, may have an influence on the parenchymal cells in some circumventricular organs. In conclusion, since neurons of the medial and periventricular parvicellular subnuclei of the PVN project to several circumventricular organs, they may be regarded as superior integrators of neuroendocrine

ISSN:0092-7317    

DOI:10.1002/cne.903060310

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

年代:1991

数据来源: WILEY

摘要:

AbstractPrevious studies showed that the nucleus locus coeruleus (LC) receives two major afferent inputs from (1) nucleus paragigantocellularis and (2) nucleus prepositus hypoglossi, both in the rostral medulla. Recent reports suggested that the midbrain periaqueductal gray (PAG) projects to the rostromedial pericoerulear area and LC. Since the PAG is a major site for control of central antinociception, and since descending nonadrenergic fibers have been implicated in pain modulation, we have investigated in detail the functional anatomy of projections from PAG to the dorsolateral pontine tegmentum. A combined anatomical and electrophysiological approach was used to assess the organization and synaptic influence of PAG on neurons in the rostromedial pericoerulear region and in LC proper.Injections of the tracer wheatgerm agglutinin conjugated to horseradish peroxidase encompassing LC proper and the rostromedial pericoerulear area retrogradely labeled neurons in PAG located lateral and ventrolateral to the cerebral aqueduct; injections restricted to LC proper did not consistently label PAG neurons. Deposits of the anterograde axonal tracerPhaseolus vulgarisleucoagglutinin into this same region of PAG labeled axons that robustly innervated the zone rostral and medial to LC. Only sparse fibers were observed in LC proper. Consistent with these results, focal electrical stimulation of LC antidromically activated only a few PAG neurons (6 of 100); all of these driven cells were located lateral and ventrolateral to the cerebral aqueduct.The majority of neurons in the rostromedial pericoerulear area were robustly activated by single pulse stimulation of PAG. In contrast, single pulse electrical stimulation of lateral PAG produced weak to moderate synaptic activation of some LC neurons; stimulation of ventrolateral PAG produced predominant inhibition of LC discharge, perhaps through recurrent collaterals subsequent to antidromic activation of neighboring LC cells.Taken together, these results indicate that PAG strongly innervates the region rostral and medial to LC, including Barrington's nucleus, but only weakly innervates LC proper. Although recent studies indicate that the dendrites of LC neurons ramify heavily and selectively in the rostromedial pericoerulear region, the results of the present physiological studies suggest that PAG preferentially targets rostromedial pericoerulear neurons rather than LC dendrites.

ISSN:0092-7317    

DOI:10.1002/cne.903060311

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

年代:1991

数据来源: WILEY