摘要:

AbstractImmunohistochemical methods were used to map the distribution of neurons exhibiting tyrosine hydroxylase‐like immunoreactivity (TH) in the brainstem of the reptileCaiman crocodilus.The results reveal that many catecholamine systems previously described in mammalian and avian species are present in the brainstem of the caiman. Within the medulla, many immunoreactive neurons surround the central canal. This neuronal field extends rostrally to the level of the dorsal motor nucleus of the vagus. Many TH neurons overlap the region of the solitary nucleus, and an extensive system of fibers derived from these neurons extends ventrally and laterally into the region immediately bordering the descending nucleus of the trigeminal nerve Some TH neurons are also present in the ventrolateral tegmentum of the medulla at this level.A large number of TH cells are present in the pons and midbrain. These include the locus coeruleus, nucleus subcoeruleus ventralis, nucleus subcoeruleus dorsalis, substantia nigra (Brauth et al., '83), and area ventralis of Tsai. The subcoeruleus nuclei are considerably larger in the caiman than in other reptilian species including turtles and lizards and closely resemble the subcoeruleus nuclei of birds in terms of position and anterior‐posterior extent. Within the diencephalon, numerous small, intensely staining, TH‐immunoreactive and CSF‐contacting neurons were observed within the preoptic recess and in close proximity to the ventricular wall at rostral hypothalamic and preoptic levels. Many intensely stained, immunoreactive cell bodies were observed in the medial hypothalamus similar in position to the A13 cell group of mammals. In the subthalamus, TH neurons completely surround the ventral peduncle of the forebrain bundle (which contains fibers of the ansa lenticularis) and extend into the ventromedial and ventrolateral thalamic areas. A rich plexus of TH‐positive axons and terminals invests the external layer of the median

ISSN:0092-7317    

DOI:10.1002/cne.902700302

出版商:Alan R. Liss, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe cranial meninges of the goldfish were studied by means of transmission electron microscopy combined with the freeze‐fracturing technique. The goldfish has three cranial meninges. The outer layer consists of flattened cells, which are stratified in 3 to 7 layers and are packed densely with many interdigitations of cell processes. The constituent cells in the outer layer have copious smooth endoplasmic reticulum and are joined by gap junctions but have no desmosomes. The intermediate layer is thin, continuous, and single cell. In the replicas, both the upper and the lower surfaces of the intermediate layer cells have numerous openings of pinocytotic vesicles, but the upper surface is characterized by round gap junctions, whereas the lower surface is identified by a linear continuation of a combination of tight junctions and gap junctions and by desmosomes. The lateral surface has a hexagonal network of tight junctions and gap junctions with internally located desmosomes, which functions as a barrier to intercellular movement of lanthanum. The inner layer consists of a meshwork of reticular cells and large intercellular spaces, in which fine granular material, capillaries, and different types of blood‐derived free cells can be found. Cells in the inner layer contain rough endoplasmic reticulum stacked in lamellae and have irregular processes joined by desmosomes. The goldfish meninges are compared with the meninges of mamm

ISSN:0092-7317    

DOI:10.1002/cne.902700303

出版商:Alan R. Liss, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe topographic distribution of aromatic L‐amino acid decarboxylase (AADC)‐immunoreactive (IR) neurons was investigated in the cat hypothalamus, limbic areas, and thalamus by using specific antiserum raised against porcine kidney AADC. The perikarya and main axons were mapped on an atlas in ten cross‐sectional drawings from A8 to A16 of the Horsley Clarke stereotaxic plane. AADC‐IR neurons were widely distributed in the anterior brain. They were identified in the posterior hypothalamic area, rostral arcuate nucleus of the hypothalamus, dorsal hypothalamic area, and periventricular complex of the hypothalamus, which contain tyrosine hydroxylase (TH)‐IR cells and are known as All to A14 dopaminergic cell groups. AADC‐IR perikarya were also found in the other hypothalamic areas where few or no TH‐IR cells have been reported: the supramamillary nucleus, tuberomamillary nucleus, pre‐ and anterior mamillary nuclei, caudal arcuate nucleus, dorsal hypothalamic area immediately ventral to the mamil‐lothalamic tract, anterior hypothalamic area, area of the tuber cinereum, retrochiasmatic area, preoptic area, suprachiasmatic and dorsal chiasmatic nuclei. We also identified them in the anterior commissure nucleus, bed nucleus of the stria terminalis, stria terminalis, medial and central amygdaloid nuclei, lateral septal nucleus, and nucleus of the diagonal band of Broca. AADC‐IR neurons were localized in the ventromedial part of the thalamus, lateral posterior complex, paracentral nucleus and lateral dorsal nucleus of the thalamus, medial habenula, parafascicular nucleus, subparafascicular nucleus, and periaqueductal gray. Conversely, we detected only a few AADC‐IR cells in the supraoptic nucleus whose rostral portion contains TH‐IR perikarya. Comments are made on the relative Idealizations of the AADCvIR and THvIR neurons, on species differences between the cat and rat, as well as on the possible physiological funct

ISSN:0092-7317    

DOI:10.1002/cne.902700304

出版商:Alan R. Liss, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractCytochrome oxidase (C.O.) was histochemically localized in the normal retina and optic tectum of goldfish in order to examine the laminar and cellular oxidative metabolic organization of these structures. In the optic tectum, C.O. exhibited a distinct laminar, regional, and cellular distribution. The laminae with highest C.O. levels were those that receive optic input, suggesting a dominant role for visual activity in tectal function. This was demonstrated by colocalizing C.O. and HRP‐filled optic fibers in the same section. However, the distribution of C.O. within the optic laminae was not uniform. Within the main optic layers, the SFGS, four metabolically distinct sublaminae were distinguished and designated from superficial to deep as sublaminae a, b, c, and d. The most intense reactivity was localized within SFGSa and SFGSd, followed by SFGSb, then SFGSc. In SFGSd, intense reactivity was found to occur specifically within a class of large diameter axons and terminals that were apparently optic since these were also labeled with HRP and cobaltous lysine applied to the optic nerve. Regional C.O. differences across the tectum were also noted. Low levels were found in neurons and optic terminals along the growing immature medial, lateral, and posterior edges of tectum, but were higher at the more mature anterior pole and central regions of tectum. This suggests that the oxidative metabolic activity is initially low in newly formed tectal neurons and optic axons, but gradually increases with neuronal growth and functional axon terminal maturation. Most C.O. staining was localized within neuropil, whereas the perikarya of most tectal neurons were only lightly reactive. Only a few neuron classes, mostly the relatively larger projection neurons, had darkly reactive perikarya.In the retina, intense C.O. reactivity was localized within the inner segments of photoreceptors, the inner and outer plexiform layers, and within certain classes of bipolar and ganglion cells. The large ganglion cells in particular were intensely reactive. Like the large diameter optic terminals in SFGSd, the large ganglion cells were preferentially filled with HRP, suggesting that they may project to tectum and are the source of the darkly reactive large diameter axons and terminals in sublamina SFGSd.We propose a new scheme to describe tectal lamination that integrates laminar differences in C.O. reactivity with classical histological work. We further suggest that these laminar patterns represent a functional substratification of the classically defined tectal laminae and, in particular, suggest that different optic sublaminae may be innervated by different classes of ganglion cell

ISSN:0092-7317    

DOI:10.1002/cne.902700305

出版商:Alan R. Liss, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractBinding of125I‐[Sar1, Ile8] angiotensin II (AII) to sections of brains from both wild and laboratory rabbits was determined by in vitro autoradiography. In the forebrain, specific high density binding was observed in the olfactory bulb, organum vasculosum of the lamina terminalis (OVLT), subfornical organ, median eminence, lateral septum, median preoptic nucleus and hypothalamic paraventricular, supraoptic and arcuate nuclei. In the midbrain, binding of the radioligand was observed in the interpeduncular and parabrachial nuclei, in the locus coeruleus, and ventrolateral pons. In the hind brain, there was dense binding of125I‐[Sar1,Ile8] All to the nucleus of the solitary tract (NTS) and to both rostral and caudal parts of the reticular formation of the ventrolateral medulla oblongata. Weaker specific binding of the radioligand to the molecular layer of the cerebellum, to the nucleus of the spinal trigeminal tract, dorsal motor nucleus of the vagus, area postema, and to a band of tissue connecting the NTS to the ventrolateral medulla was also observed. Binding of the ligand to circumventricular organs such as the OVLT, subfornical organ, and median eminence suggests that these are sites in the brain of the rabbit at which blood‐borne All may exert influences on the central regulation of fluid balance and pituitary hormone secretion, although All of neuronal origin could also act at these sites. Binding of the radioligand in several other brain regions suggests that angiotensin II of cerebral origin may be involved in a number of different aspects of brain function in the rabbit. The finding of dense binding in the NTS and ventrolateral medulla, which are involved in autonomic activity and are also sites of catecholamine‐containing neurons, raises the possibility of angiotensin interaction with these neurons and involvement in autonomic f

ISSN:0092-7317    

DOI:10.1002/cne.902700306

出版商:Alan R. Liss, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractWe have observed that WGA‐HRP injections in lobule VIII of the mouse result in the labeling of mossy fiber terminals in the anterior lobe (lobules I‐V), which are distributed in five distinct parasagittal bands. Injections in the anterior lobe label mossy fiber terminations in lobules VIII and IX. We interpret these results as indicating that an extensive system of mossy fiber collaterals exists between the anterior lobe and lobule VIII (less so to IX), which terminates as discrete parasagittal bands in the anterior lobe. Intermediate bands are thus occupied by fibers that do not send collaterals to the posterior vermis (VII–IX).In an attempt to identify the source(s) of this collateral system we have used double retrograde tracing techniques. Following injections of one tracer in the anterior lobe and another in lobule VIII we observe large numbers of double retrogradely labeled neurons in the lateral reticular nucleus, the basilar pontine nuclei, and the spinal cord. Thus, these mossy fiber sources are the most likely origins for the banded collateral system. Our studies do not allow us to distinguish whether one, or more than one, of these regions contribute to the s

ISSN:0092-7317    

DOI:10.1002/cne.902700307

出版商:Alan R. Liss, Inc.    

年代:1988

数据来源: WILEY

ISSN:0092-7317    

DOI:10.1002/cne.902700308

出版商:Alan R. Liss, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractCorticotropin releasing factor (CRF)‐containing afferents to the rat lateral septum (LS) have been determined by means of cobalt‐enhanced immunohistochemistry, tracing of retrograde transport of horseradish peroxidase (HRP), and by lesioning experiments.When unilateral lesions included the rostral part of the hypothalamus, CRF‐like immunoreactive (CRFI) ipsilateral fibers in the LS decreased in number. Lesions in other brain regions did not cause alterations in the septal CRFI fibers. These findings suggest that the septal CRFI fibers originate in the rostral part of the hypothalamus. Furthermore, combined HRP and immunohistochemical staining cm the same sections demonstrated double‐labeled cells in two discrete areas within the rostral hypothalamus: one was the perifornical hypothalamic area (PeF) at the level of the paraventricular hypothalamic nucleus, and the other was the most caudal part of the anterior hypothalamic nucleus (AHc). These findings show that a large proportion of the CRFI projections to the LS have their origins in the PeF

ISSN:0092-7317    

DOI:10.1002/cne.902700309

出版商:Alan R. Liss, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe source, distribution, and morphology of axons displaying calcitonin gene‐related peptide (CGRP) immunoreactivity in the central amygdaloid nucleus of the adult rat were investigated with immunohistochemical techniques, both alone and in combination with retrograde transport of fluorescent tracers. An extremely dense plexus of CGRP‐immunoreactive axons is differentially concentrated within the lateral capsular and lateral central subdivisions of the central nucleus, and much lighter concentrations of labeled fibers are present in the rostral part of the medial subdivision. No immunoreactive neurons were observed in the central nucleus in any of the experimental animals. The immunoreactive axons characteristically form prominent pericellular terminal arborizations surrounding unlabeled neurons. The number of cells receiving this dense input increases at caudal levels of the central nucleus. Retrograde label of central nucleus neurons by dye transport from injections into the pontine parabrachial nucleus and the nucleus of the tractus solitarius combined with CGRP immunohistochemistry established that many neurons in the central nucleus which receive dense pericellular innervation from CGRP‐immunoreactive axons are projecting caudally to the parabrachial nucleus or, to a lesser extent, to the nucleus tractus solitarii. Central amygdaloid injections of rhodamine‐labeled microspheres or fluorogold followed by immunohistochemical localization of cellular CGRP immunoreactivity revealed that the central amygdaloid CGRP fiber plexus originates bilaterally from the parabrachial nucleus. These multipolar CGRP‐containing neurons are preferentially concentrated in the external medial and external lateral subnuclei, in the ventral aspect of the parabrachial nucleus. These results relating central amygdaloid CGRP to ascending and descending brainstem pathways, taken together with the extreme density of the fiber plexus, strongly suggest the relevance of the CGRP input to central nucleus function in cardiovascular and other autonomic r

ISSN:0092-7317    

DOI:10.1002/cne.902700310

出版商:Alan R. Liss, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractSubstance P (SP) and catecholamines, particularly adrenaline, have been implicated in cardiovascular responses mediated by neurons in the rostral ventrolateral medulla (RVL). Immunoperoxidase labeling of an antiserum against SP and/or immunoautoradiographic localization of catecholamine (tyrosine hydroxylase—TH)‐ or adrenaline (phenylethanolamine N‐methyltransferase—PNMT)‐synthesizing enzymes were examined histologically to determine the cellular basis for a functional interaction involving either synaptic or intracellular relations between these putative transmitters in the adult rat RVL. Peroxidase labeling for SP was localized in perikarya, dendrites, and axon terminals. Most of these perikarya were located medial and ventral to those labeled with TH or PNMT within the same section. However, as others have previously demonstrated by light microscopy, colocalization of SP‐like immunoreactivity (SPLI) and PNMT was seen in a few perikarya of colchicine treated animals. Both single‐ and dual‐labeled perikarya contained abundant dense core vesicles.The terminals with SPLI were 0.4–1.4 μm in diameter and contained a few mitochondria, a large population of small, clear vesicles, and from three to 11 large dense core vesicles. In some cases the terminals were seen in continuity with more proximal processes of neurons in the RVL. These terminals formed synapses with a few perikarya and many dendrites, some of which also contained SPLI. In the material dually labeled for TH and SP, terminals with SPLI (n = 32) formed synaptic junctions primarily with TH‐labeled dendrites (69%); the remainder were with TH‐labeledperikarya (6%) or with unlabeled dendrites (25%). The axosomatic junctions were exclusively symmetric, whereas the majority of axodendritic junctions were primarily asymmetric on small dendrites (0.8–1.0 μm in diameter) or dendritic spines. In sections dually labeled for PNMT and SP, the terminals containing SPLI (n = 37) formed synaptic associations with PNMT‐labeled perikarya (11%), PNMT‐immunoreactive dendrites (59%), or with perikarya and dendrites lacking PNMT immunoreactivity (30%). The axosomatic junctions were all symmetric and most often associated with the spinous portion of the soma. The axodendritic junctions were primarily asymmetric and were found both on the shaft and spinous portion of the PNMT‐labeled dendrites. In addition, both TH‐ and PNMT‐labeled somata and dendrites received symmetric and asymmetric contacts from terminals lacking SPLI.These findings provide ultrastructural evidence that in the rat RVL, SP or a closely related neurokinin located in intrinsic neurons or other afferents provides a major direct input to adrenergic neurons. Additionally, the peptide may modulate the activity of adrenergic neurons through synapses with neurons containing SP or other transmitters or

ISSN:0092-7317    

DOI:10.1002/cne.902700311

出版商:Alan R. Liss, Inc.    

年代:1988

数据来源: WILEY