摘要:

AbstractThe distribution of presumptive glutamergic and/or aspartergic neurons retrogradely labeled following injections of3H‐D‐aspartate (3H‐D‐Asp) into the ventral Striatopallidal region was compared with the distribution of neurons labeled by comparable injections of wheat germ agglutunin‐horseradish peroxidase (WGA‐HRP). The afferents labeled by3H‐D‐Asp were a subset of those labeled by WGA‐HRP. The major sources of afferents to the nucleus accumbens and olfactory tubercle that could be labeled by3H‐D‐Asp were in the medial frontal and insular cortices; the olfactory cortex; the lateral, basolateral, and basomedial amygdaloid nuclei; and the midline nuclear complex of the thalamus. The corresponding afferents to the ventral pallidum arose in the central, medial, and basomedial amygdaloid nuclei and the midline thalamic nuclei. In addition, the nucleus of the lateral olfactory tract was moderately or heavily labeled by3H‐D‐Asp injections into all three areas, and cells were labeled in the subiculum following injection in the anteromedial part of the nucleus accumbens. Conversely the ventral Striatopallidal structures themselves were, at best, sparsely labeled by any of the3H‐D‐Asp injections. Neurons in the substantia nigra, ventral tegmental area, dorsal raphe, and locus coeruleus were labeled by WGA‐HRP but not by3H‐D‐Asp, except for an occasional cell in the raphe. The results indicate that3H‐D‐Asp is a specific retrograde tracer and suggest that there are widespread, presumably excitatory, glutamergic and/or aspartergic inpu

ISSN:0092-7317    

DOI:10.1002/cne.902580302

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe distribution, morphology, and synaptic contacts of serotoninergic fibers were studied with immunocytochemical methods in the lateral geniculate complex of the cat. The serotonin‐immunoreactive fibers are diffusely distributed throughout the main laminae of the dorsal lateral geniculate nucleus (dLGN) and the perigeniculate nucleus (PGN) and reach a particular density in the ventral lateral geniculate nucleus (vLGN). The labeled fibers are in most cases very thin and sometimes varicose. There is no obvious order in their distribution pattern except that they sometimes partially encircle the unlabeled cell bodies of the dLGN.The synaptic connections of the serotoninergic fibers were investigated mainly in the A laminae of the dLGN. Few synaptic complexes were found, most of them with asymmetric morphology. The postsynaptic elements were small dendritic profiles. Perisomatic serotoninergic fibers were seen, but no convincing synaptic contacts were found between labeled fibers and cell somata. In the dLGN, serotoninergic profiles were almost exclusively confined to the extraglomerular neuropile. In the PGN serotoninergic fibers also contacted dendritic profiles and formed asymmetrical synapses, but as in the geniculate, synaptic specializations were very rar

ISSN:0092-7317    

DOI:10.1002/cne.902580303

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

年代:1987

数据来源: WILEY

摘要:

AbstractLucifer yellow was used to label axons of 32 physiologically defined SI afferent fibers and 23 physiologically defined S2 afferent fibers of the goldfish sacculus. Analysis of these labeled fibers allowed us to study the relationship between electrical activity in these primary neurons and the morphology of their peripheral arborizations in the sensory macula. Morphological characteristics were highly indicative of response type: The peripheral arborizations of individual S1 fibers occupied a relatively small region (approximately 40 μm in diameter) in the rostral one‐fourth of the saccular macula, whereas those of individual S2 fibers covered a larger area (roughly 80 μm across) in the caudal part of the macula. In addition to this rostrocaudal dimension, a ventral projection was related to a rarefaction response, a dorsal projection was related to a compression response, and a two‐sided innervation was related to fibers having both responses. S1 fibers had either large or small terminals; the S2 fibers had only small terminals. On average, S1 fibers gave rise to approximately four terminals (e.g., seven small terminals or one to two large terminals) and S2 fibers approximately ten terminals. Spontaneous discharges were absent in all S1 fibers but present in some S2 fibers. Such S2 fibers showed spontaneous activity of either an irregular type or a burst type. In these, there was a tendency for fibers having more extensive arborizations to exhibit a burst type of spontaneous discharge. We conclude that structure‐function relationships can be determined for these primary

ISSN:0092-7317    

DOI:10.1002/cne.902580304

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

年代:1987

数据来源: WILEY

摘要:

AbstractAromatase activity was determined in small discrete areas of the brain of the African catfish,Clarias gariepinus, by a radiometric assay. The fore‐and midbrain were divided into eighteen 500‐μm transverse sections. From these sections several punches (0.3 mg of tissue) were taken and incubated with [19‐3H]‐androstenedione. The aromatase activity, calculated from the release of tritium label during aromatization, is expressed in pmol mg−1tissue hour−1.The highest activity (3.7 pmol) was detected in the preoptic region. The more caudally located area tuberalis, including the nucleus lateralis tuberis and the nucleus recessus lateralis, also showed a relatively high activity (2.5 pmol).A similar activity was found in the most rostral part of the telencephalon and the dorsal parts of the mesencephalon, i.e., the tectum opticum and torus semicircularis (2.3 pmol). A moderate aromatase activity was observed in remaining parts of the brain, except the cerebellum and hindbrain, in which aromatase activity was hardly detectable (0.1–0.3 pmol).It is concluded that a high aromatase activity is present in regions known to be involved in the regulation of reproduction. Since both the torus semicircularis and the tectum opticum display a high aromatase activity, it is suggested that also these structures are involved in reproduc

ISSN:0092-7317    

DOI:10.1002/cne.902580305

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

年代:1987

数据来源: WILEY

摘要:

AbstractCollateral axonal branching to the cerebellum from the lateral reticular nucleus (LRN) was studied in the rat by using the fluorescent double‐labeling technique. Following injection of Fast Blue (FB) into the cerebellar cortex, followed 3 days later by injection of Nuclear Yellow (NY) into a different region of the cortex, single‐ and double‐labeled cells were found within the LRN. Most LRN‐cerebellar projections were bilateral with ipsi‐lateral preponderance, except for the projection to the paramedian lobule, which was completely ipsilateral.The dorsolateral area of the magnocellular division of the LRN contained cells whose axons branch to terminate in the rostral anterior lobe and the caudal part of the ipsilateral paramedian lobule (hindlimb areas of the cerebellar cortex), while the medial area of the LRN contained cells that supply, via collateral axonal branching, the caudal area of the contralateral anterior lobe and the rostral part of the ipsilateral paramedian lobule (forelimb areas of the cerebellum). Branched LRN‐cerebellar axons projected to both hemispheres and to both sides of the caudal anterior lobe. No axonal branching was evident in the LRN‐cerebellar projection to the rostral anterior lobe. The projection to the anterior and posterior lobe vermis also contained collateral axo

ISSN:0092-7317    

DOI:10.1002/cne.902580306

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

年代:1987

数据来源: WILEY

摘要:

AbstractIntramuscular injections of either horseradish peroxidase (HRP) or wheat germ agglutinin‐conjugated horseradish peroxidase (WGA‐HRP) were made into the masseter muscle of rats. Both tracers labeled primary sensory neurones in the V mesencephalic nucleus, motoneurones in the V motor nucleus, and some motoneurones in die facial motor nucleus. WGA‐HRP labeled additional neurones in the V main sensory nucleus and the rostral pole of the V nucleus oralis. These were classed as interneurones because they lay in areas outside those known to contain either first‐order afferent or motoneurone somata. We argue that these were labeled by retrograde transport of tracer because they lay close to the V motor nucleus, and from some of them processes could be followed into the region of the V motor

ISSN:0092-7317    

DOI:10.1002/cne.902580307

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

年代:1987

数据来源: WILEY

摘要:

AbstractThalamocortical relay neurons from the rat ventrobasal nucleus were identified physiologically and injected intracellularly with horseradish peroxidase. The axons of those cells were followed through serial sections in order to determine if collaterals were given off within the ventrobasal nucleus or the thalamic reticular nucleus. No local collaterals were seen in the ventrobasal nucleus, thus indicating that interactions between relay cells in this nucleus are minimal. Of axons that could be followed into the internal capsule, 76% gave off visible collaterals in the thalamic reticular nucleus. Half of these axons had collaterals showing extensive branching with the potential of innervating a large number of thalamic reticular neurons. The other half had short, simple branches of restricted extent. No correlations were found between the physiological properties of a cell and the existence or extent of axon collaterals. These results describe the anatomical basis for the initial part of a feedback loop through the thalamic reticular nucleus that provides the major inhibitory influence on rat ventrobasal neurons.

ISSN:0092-7317    

DOI:10.1002/cne.902580308

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

年代:1987

数据来源: WILEY

摘要:

AbstractWe have conducted anatomical and physiological experiments to investigate the functional organization of the dorsal thalamus in the northern leopard frog (Rana pipiens pipiens). Our studies provide evidence for parallel auditory processing at this level of the frog's brain. Acoustically evoked potentials were recorded from the posterior and central thalamic nuclei and several differences in sound‐evoked activity were noted between them: (1) the amplitude of acoustically evoked potentials (AEPs), in response to a standard search stimulus, was always greater in the central, as opposed to the posterior, nucleus; (2) the posterior, but not central, nucleus exhibited the phenomenon of nonlinear summation when 350‐Hz and 1,700‐Hz tones were presented simultaneously rather than individually; and (3) the central, but not posterior, nucleus showed selectivity for the repetition rate of pulsed sound signals. The posterior and central thalamic nuclei also possessed distinct innervation patterns as revealed by the HRP transport patterns arising from these structures. The central nucleus was reciprocally connected with the major auditory relay stations along the frog's central auditory pathway including the superior dive, nucleus of the lateral lemniscus, and the torus semicircularis. Major projections to the lateral thalamic nucleus, ventral hypothalamus, and the telencephalic striatal complex were also observed. The posterior nucleus, on the other hand, established reciprocal connections primarily with the medial reticular nucleus, ventral mid‐brain tegmentum, and structures constituting of the ventral thalamic nuclei, particularly the nucleus of Bellonci. Thus, time and frequency cues contained within the species mating call, and conveying information concerning species identity, appear to be processed independently within the frog's thalamus with separate neural channels f

ISSN:0092-7317    

DOI:10.1002/cne.902580309

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

年代:1987

数据来源: WILEY

摘要:

AbstractFunctional vascular connections must form rapidly to prevent ischemic damage to grafted neural tissues. The temporal sequence by which transplant circulation is re‐established provides information about the angiogenic capacity of either intact or damaged CNS blood vessels. This study compares the time course and mechanism of vascular reperfusion in allografts of superior cervical ganglia or adrenal medulla inserted either into the fourth ventricle or directly into the parietal cortex of perinatal rats. Tritiated thymidine was administered lo recipients to determine angiogenic patterns at various postoperative time periods. After processing for light microscopic autoradiography, host and graft endothelial labelling indices were determined in order to establish the temporal sequence and location of vascular proliferation, Correlative electron microscopy depicted the morphological changes in transplant vasculature. Some recipients were prelabelled with3H thymidine prior to transplantation to determine if host vessels invaded the grafts.Intraventricular graft vessels initially collapsed but sustained minimal ischemic damage and were completely reperfused by 24 hours postoperative. Adjacent intact host vessels attained peak3H thymidine incorporation at 20 hours. Intrinsic graft vessels were radioactively labelled only after 48 hours. Intraparenchymal transplants surrounded by minimal trauma exhibited a similar temporal sequence of reperfusion and host endothelial proliferation. Intrinsic graft vessels in intraparenchymal grafts sustained more severe damage. With increased trauma, a concomitant delay in graft reperfusion time was observed. Grafts within prelabelled hosts rarely contained any labelled endothelium, indicating that anastomotic connections were made between original, intrinsic graft vessels and nearby host vascular sprouts.This study demonstrates that mature autonomic tissue stimulates the growth of adjacent host vessels when transplanted to undamaged brain surfaces. The anastomosis of nascent host vessels with pre‐existing graft vessels is responsible for the rapid re‐establishment of circulation within the transplants. A similar mechanism occurs within intraparenchymal grafts, although the rapidity of reperfusion appears to be predicated on the amount of trauma present at the graft

ISSN:0092-7317    

DOI:10.1002/cne.902580310

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

年代:1987

数据来源: WILEY

摘要:

AbstractRetinal projections to the pretectal and terminal accessory optic nuclei were studied in normal wild‐type mice and mutant mice with abnormal optokinetic nystagmus (OKN, Mangini, Vanable, Williams, and Pinto:J. Comp. Neurol. 247:191–209, '85). The mutants used were (1) pearl, which exhibits an inverted OKN in response to stimulation of only the temporal retina, and (2) beige and beige‐J, which show inverted OKN in response to stimulation of only the temporal retina and, in addition, exhibit eye movements with a vertical component in response to horizontally moving, full‐field stimuli. These projections were studied following intraocular injections of3H‐proline or horseradish peroxidase (HRP) with, respectively, light microscopic auto‐radiography or HRP histochemistry.In wild‐type mice, strong contra lateral retinal projections covered the entire nucleus of the optic tract, the anterior and posterior divisions of the olivary pretectal nucleus, and the posterior pretectal nucleus. Similar heavy contralateral projections were distributed over the dorsal and medial terminal nuclei of the accessory optic system. Also, terminals sparsely covered the entire neuropil of the contralateral lateral terminal nucleus in some but not all wild‐type mice. The most prominent accessory optic input was to the medial terminal nucleus and was provided by the inferior fasciculus of the accessory optic tract. A typical mammalian superior fasciculus of the accessory optic system with anterior, middle, and posterior components was present. Ipsilateral label was found in anterior and posterior olivary pretectal nuclei in all of the wild‐type animals, but was found inconsistently in the ipsilateral terminal accessory optic nuclei.The pattern of contralateral retinal projection to the nucleus of the optic tract and posterior pretectal nucleus in mutants was indistinguishable from that seen in the normal wild‐type mice. However, retinal inputs to the ipsilateral anterior and posterior olivary pretectal nuclei were significantly reduced in pearl mutants and were exceedingly sparse in the beige and beige‐J mutant mice, while the contralateral inputs to these nuclei were increased in a complementary fashion in the mutants. The labeling of the accessory optic input to the contralateral dorsal terminal nucleus appeared to be substantially reduced in all of the mutant mice. The size of the principal accessory optic fascicle, the inferior fasciculus, was significantly smaller in beige, beige‐J, and pearl mice; this reduction was greater in the beige and beige‐J than in the pearl mice. As with the wild‐type mice, ipsilateral projections to the terminal accessory optic nuclei were rarely found in the mutant mice.The reduced inferior fasciculus of the accessory optic tract of the beige and beige‐J mutants suggests that the optic inputs that reach the medial terminal nucleus may be reduced or abnormal. These mutants also show an abnormal vertical component of eye movements in response to horizontally moving stimuli. Thus, abnormal responses mediated by neurons of the medial terminal nucleus may be involved in th

ISSN:0092-7317    

DOI:10.1002/cne.902580311

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

年代:1987

数据来源: WILEY