摘要:

AbstractA Golgi‐Cox, histofluorescence, and electron microscopic examination of the serotonergic raphe nuclei of the rabbit medulla has revealed a large, vertically‐oriented midline dendrite bundle extending from the floor of the fourth ventricle to the ventral boundary of nucleus raphe pallidus. The bundle was confined to the medulla, and averaged 150–200 μm in width in the adult. This dendrite bundle received contributions from four major sources: (1) Dendrites of midline and paramedian neurons of nucleus raphe obscurus; (2) Dendrites of midline and paramedian neurons of nucleus raphe pallidus; (3) Shafts from tanycytes located on the midline floor of the fourth ventricle; and (4) Dendrites from neurons of the medullary reticular formation. Perikarya and dendrites of serotonergic raphe neurons frequently abutted tanycyte shafts, midline blood vessels, and perikarya and dendrites of other raphe neurons. The tanycyte shafts extended from the floor of the fourth ventricle into the bundle, and often ran the entire length of the bundle, where they intertwined themselves among neurons and dendrites of the medullary raphe nuclei. This study suggests that neurons of the medullary raphe may be influenced by communication channels including dendro‐dendritic contacts within the midline bundle, fourth ventricular cerebrospinal fluid‐borne influences through tanycyte shafts, blood‐borne influences through the direct neuronal‐vascular relationship in the raphe, and traditionally described axonal contacts impinging upon raphe neurons. We suggest that the raphe neurons might act as both neurons and endocrine‐neural

ISSN:0092-7317    

DOI:10.1002/cne.901830102

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

年代:1979

数据来源: WILEY

摘要:

AbstractSpecific histochemical techniques for the demonstration of catecholamine and acetylcholinesterase have been used to study the distribution of adrenergic and cholinergic nerves on the cerebral blood vessels of bullfrog,Rana catesbeiana.The adrenergic nerve meshworks on the cerebral arteries of bullfrog were less dense, had a more elongate appearance along the arterial axis as compared with those of mammals and were rather similar to those of snakes. The nerve plex‐uses on the cerebral carotid artery and its main branches were somewhat denser than those on the basilar artery.The most characteristic feature of innervation in the bullfrog cerebral vessels was that no acetylcholinesterase‐positive fibres were observed on the extraparenchymal arteries, whereas, in all higher vertebrates investigated so far, the cerebral arteries have been found to be dually innervated although differences in the density of innervation of the two nerves may exist. This suggests that the peripheral adrenergic innervation on the cerebral blood vessels appeared earlier than the cholinergic one in the evolution of vertebrates.On the other hand, both adrenergic and acetylcholinesterase‐positive fibres were observed in close contact with parenchymal arterioles and capillaries suggesting the possible existence of a dual central innervation. This feature, however, was by no means common. Thus, the central neurons have a significant influence on the cerebral circulation in the bullfrog is somewhat equivocal.Most of the pial and the parenchymal small vessels and the parenchymal capillaries exhibited a heavy acetylcholinesterase activity on the vascular walls. Although the significance of the enzyme is obscure as yet, this has to be considered in relation to the regulatory mechanism of the cerebral circul

ISSN:0092-7317    

DOI:10.1002/cne.901830103

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

年代:1979

数据来源: WILEY

摘要:

AbstractAutoradiographic tracing methods were employed to study the course and distribution of the rubroolivary tract following unilateral injections of tritiated leucine into the rostral red nucleus of seven rhesus monkeys. A topographic organization of projections to the ipsilateral principal nucleus of the inferior olivary complex was demonstrated. Lateral and medial portions of the rostral red nucleus projected to medial parts of the dorsal and ventral laminae of the principal inferior olive respectively; neurons in intermediate lateralities emitted fibers which terminated in lateral parts of the principal olive. Injections involving the oral end of the rostral red nucleus elicited label overlying the medial accessory olive in addition to the principal nucleus. Projections to the medial accessory olive may have arisen from the rostral end of the red nucleus and/or the immediately adjacent tegmentum. There were no projections to the dorsal accessory olive. Fibers of rubral origin also were distributed ipsilaterally to several reticular nuclei including the pedunculopontine, pontis oralis, caudalis, and gigantocellularis.

ISSN:0092-7317    

DOI:10.1002/cne.901830104

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

年代:1979

数据来源: WILEY

摘要:

AbstractWe studied the receptive field properties of 460 cells in the cat's dorsal lateral geniculate nucleus (LGNd), 108 cells were located in the medial interlaminar nucleus (MIN) and 352 in the laminated part of the LGNd.In both the MIN and laminated parts of the LGNd, relay cells belonging to all three functional classes (W, X and Y) have been identified. Of cells in the laminated LGNd, about 32.5% were Y cells, about 54.5% were X cells and about 8.5% were W cells. By contrast, in the MIN, about 84% were Y cells, only about 4.5% being X cells and about 7.5%, W cells. In the laminated LGNd, Y cells represented 25% of cells with receptive fields near the area centralis (0–3° eccentricity group) and about 42% in the group of cells with the most peripherally located receptive fields (20–40° eccentricity group). A similar but much weaker trend was observed in the MIN. In the laminated LGNd but not in the MIN the receptive field center sizes increased with increasing eccentricity of receptive field position. At any eccentricity, receptive field centers of MIN Y cells tended to be larger than those of Y cells in the laminated LGNd.Response latency ranges to orthodromic and antidromic stimulation were the same for cells located in the laminated LGNd and those in the MIN. However, the mean response latency to stimulation of the optic chiasm was significantly shorter for Y cells in MIN than for Y cells in the laminated LGNd.Our results suggest that the most numerous cells observed histologically in the MIN, class 1 cells of Guillery ('66) are morphological equivalents of Y

ISSN:0092-7317    

DOI:10.1002/cne.901830105

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

年代:1979

数据来源: WILEY

摘要:

AbstractThe distribution in the spinal cord of the rat of preganglionic neurons sending fibers into the hypogastric nerve was determined with the retrograde transport of horseradish peroxidase (HRP). Labeled cells were present in the intermediate gray matter of spinal segments L1‐L2. The majority (81%) of HRP‐filled cells formed a continuous column along the midline in the dorsal gray commissure. This cell column was termed the dorsal commissural nucleus (DCN). The remainder of HRP‐labeled cells were present bilaterally in the middle and lateral regions of the intermediate gray; the majority of the latter cells were located along the lateral border of the intermediate gray.The present finding of a midline preganglionic autonomic cell column in the spinal cord of a mammal is contrary to previous reports, in which sympathetic preganglionic neurons have been localized primarily in the lateral intermediate gray. The DCN may be species‐specific and related to the system of short adrenergic neurons present in the

ISSN:0092-7317    

DOI:10.1002/cne.901830106

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

年代:1979

数据来源: WILEY

摘要:

AbstractTransverse sections of the cochlear nerve, silver‐stained surface preparations of the cochlea, and silver‐ and osmium‐stained tangential sections of the cochlea of the house mouse were made to determine the number and density of nerve fibres entering the organ of Corti and their distribution to inner and outer hair cells along the cochlear spiral. A number of 12,578 ± 819 fibres was counted within the cochlear nerve, which is almost equal to the total number of 12,350 ± 810 fibres entering the organ of Corti. The 12,350 fibres divide into 9,780 (≙ 79%) fibres running to the inner hair cells, 703 (≙ 6%) basilar (afferent) fibres and 1,867 (≙ 15%) upper tunnel radial (efferent) fibres innervating the outer hair cells. About 93% of all afferent fibres are connected to the inner hair cells, and only 7% innervate outer hair cells. The density of fibres running to the inner hair cells varies considerably and has a significant (p<0.01) absolute and relative maximum 3.7 mm and 2.9 mm from the apex respectively (total length: 6.84 mm) and decreases toward apex and base. The density of afferent fibres running to the outer hair cells shows a slow increase up to 2 mm from the apex, and remains on a constant low level (5.5 fibres per 40 μm) down to the base. The density of efferent fibres running to the outer hair cells increases linearly up to about 2 mm from the apex, remains rather constant (10 fibres per 40 μm) from 2 mm to 4 mm, and then decreases toward the base. Generally, the outer hair cells show a convergent innervation pattern, the inner hair cells a divergent one. The significance of the present measurements is discussed in relation to respective results from other mammals and in relation to audi

ISSN:0092-7317    

DOI:10.1002/cne.901830107

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

年代:1979

数据来源: WILEY

摘要:

AbstractNeurogenesis in the rat septal region was examined with3H‐thymidine autoradiography. The rats in the prenatal groups were the offspring of pregnant females given two injections of3H‐thymidine on consecutive days in an overlapping series: embryonic day (E) 13 + E14, E14 + E15, … E21 + E22. The rats in the postnatal groups were injected in a nonoverlapping series: the day of birth and postnatal day (P) 1, P2 + P3, P3 + P4. On 60 days of age, the percentage of labelled cells and the proportion of cells added during each day of formation were determined at several anatomical levels within the midline nuclear group (nucleus of the diagonal band, medial and triangular septal nuclei), the lateral septal nucleus, and the ventrolateral nuclear group (nucleus accumbens, bed nuclei of the stria terminalis and the anterior commissure). The neurons within each nuclear group form in significantly different waves, those of the midline group forming between E13‐E17, the lateral septal nucleus between E15‐E19, the bed nuclei of the stria terminalis and anterior commissure between E14‐E18, the nucleus accumbens between E17‐P2. All nuclei and nuclear groups show characteristic gradients of formation. Both the midline nuclear group and the bed nucleus of the stria terminalis (including the commissural bed nucleus) have their earliest forming neurons lying near the crossing of the anterior commissure; younger neurons are located both rostrally and caudally with the youngest neurons lying in the most rostral extension of the diagonal band nucleus and the strial bed nucleus. The lateral septal nucleus forms along a strong mediolateral gradient throughout its length after neurogenesis is almost complete in the midline nuclear group. Throughout the length of the nucleus accumbens, the oldest neurons are located ventrally while progressively younger cells are found dorsally beneath the inferior horn of the late

ISSN:0092-7317    

DOI:10.1002/cne.901830108

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

年代:1979

数据来源: WILEY

摘要:

AbstractMorphogenesis of the septal region was examined in normal rat embryos from embryonic day (E) 10 to E22. The greater part of the septal region is postulated to form from two separate anlagen which can be clearly distinguished in the telencephalon by E13 and E14. One lies in the anterior ventromedial wall and presumably forms the nucleus of the diagonal band, medial, lateral, and triangular septal nuclei. The other lies in the posterior ventrolateral ridge and presumably forms the bed nuclei of the stria terminalis and the anterior commissure. On E15, the early differentiating cells in these anlagen fuse in the same region where the anterior commissure will cross on E17. With later embryonic development, differentiating cells of the strial bed nucleus accumulate rostral and caudal to the fused area. The same pattern is found in the medial and triangular septal nuclei and in the nucleus of the diagonal band. The differentiating cells of the lateral septal nucleus accumulate dorsal and lateral to the medial and triangular septal nuclei. On E16 and E17, a prominent subependymal zone develops in the anterior septal region and presumably gives rise to the nucleus accumbens.A quantitative analysis was made of three cell zones (neuroepithelium, subependymal zone, differentiating cell zone) at coronal levels through the developing nucleus accumbens and the nucleus of the diagonal band (anterior level) and the medial and lateral septal nuclei (middle and posterior levels). At all levels, the area of the neuroepithelium continually declines, that of the differentiating cell zone continually increases, and that of the subependymal zone shows a rise and decline. On a proportional basis, both the neuroepithelium and subependymal zone occupy significantly more area anteriorly than posteriorly, while the differentiating cell zone shows the reverse gradient. To accurately locate regions of primitive mitotic and migratory cells within the zones at each level, the number of cells surviving a single exposure to 200 R X‐rays in embryonic brains (E15‐E22) were compared with controls. Each zone responded differently to X‐ray insult. The radiosensitivity of the neuroepithelium decreases significantly after E19; the subependymal zone is highly radiosensitive throughout; the differentiating cell zone is radioresistant throughout. The significance of these findings is discussed in the light of the autoradiographic determination of the time of formation of septal neurons (Bayer,

ISSN:0092-7317    

DOI:10.1002/cne.901830109

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

年代:1979

数据来源: WILEY

摘要:

AbstractThe morphology is described of a number of non‐spiking interneurones in the metathoracic ganglion of the locust that control motor neurones innervating muscles in the coxa and femur of a hind leg. The nonspiking interneurones are penetrated with microelectrodes, physiologically characterized, injected with cobalt, and the stain subsequently intensified with silver. The interneurones have diverse shapes but all arelocal, intraganglionicinterneurones. Their cell bodies are 10–20 μm in diameter and lie in either the ventral or dorsal layers of cell bodies that form a cortex around the ganglion. The branches of the interneurones are profuse and overlap those of the motor neurones that they affect. One interneurone may have branches in both the most ventral and the most dorsal areas of the neuropile. Most interneurones have branches only in one half of the ganglion, but one interneurone has extensive and asymmetrical regions of branches in both halves of the ganglion (fig. 4). Similar physiological effects can be mediated by interneurones with distinct morphologies. For example, the single slow extensor motor neurone is excited by six distinct morphological types of interneurones (figs. 10–13). It is suggested that as many as 65% of the neurones within a ganglion may be local interneurones, many of which in turn may be non

ISSN:0092-7317    

DOI:10.1002/cne.901830110

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

年代:1979

数据来源: WILEY

摘要:

AbstractThe central projections of the glossopharyngeal and vagus nerves in the mallard have been studied with the Fink‐Heimer I method and are compared to those of the trigeminal and facial nerves. The N. vagus projects ipsilaterally and contralaterally upon the central nuclei of the solitary complex, except the most rostral part of it, upon the n. sulcalis dorsalis, the parasolitary nuclei and the n. commissuralis. The glossopharyngeal nerve contributes to the rostral pole of the n. centralis anterior and to the n. ventrolateralis anterior of the solitary complex, but it has also terminal fields in a cellgroup sIX of the principal sensory trigeminal nucleus, in a small cellgroup sIXd on the dorsum of the descending trigeminal tract, in the n. interpolaris of this tract and in nuclei of the cuneate complex. There is hardly any overlap of the respective terminal fields. The convergence of projections from N VII and N IX can be connected with the presence of tastebuds in upper and lower bill and in the soft palate. The converging projections from N V and N IX in “trigeminal” nuclei may reflect the functional coherence of the mechanoreceptors in bill and tongue. It is suggested that these nuclei play a role in the feeding beh

ISSN:0092-7317    

DOI:10.1002/cne.901830111

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

年代:1979

数据来源: WILEY