摘要:

AbstractCertain sequential models of the so‐called synaptic triadic arrangements (TSA) occurring in sensory nuclei are analyzed. The considerations addressed mainly to the lateral geniculate body. The model is based on the assumption that the neurons establishing these triads consist of conditionally coupled decision‐making subunits. It might be concluded that this and similar arrangements could play a role in the discrimination between stationary and moving retinal inputs and in the detection of temporal correlations in certain input chann

ISSN:0360-4012    

DOI:10.1002/jnr.490030102

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

年代:1977

数据来源: WILEY

摘要:

AbstractA method to measure the “in vitro” RNA release from rat brain cell nuclei was described. Nuclear RNA was prelabelled “in vivo” for 30 or 120 min. In the first case the released RNA was heterogeneous and its electrophoretic mobility was similar to that of cytoplasmic messenger RNAs; nuclei prelabelled for 120 min mostly released the two major species of ribosomal RNAs. The release of mRNA form the nuclei increased during cerebral development while that of the ribosomal RNAs did not. The increased capacity of the nuclei to release “rapidly labeled” RNA with age neither determined an increase of the polysomal population, nor seemed to be dependent on cytoplasmic mac

ISSN:0360-4012    

DOI:10.1002/jnr.490030103

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

年代:1977

数据来源: WILEY

摘要:

AbstractThe present report incorporates the histochemical mapping of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) among the various and fiber tracts of the diencephalons and mesencephalon of Calotes versicolor.The various nuclei, for both enzymes, present varying degrees of staining, ranging from negative nuclei, on the one hand, to mild and intense staining on the other hand. Almost all the fiber tracts reveal intense activity in BChE preparations, while they demonstrate mild and moderate activities for AChE.The nature of the various nuclei in relation to enzymativ patterns is discussed.

ISSN:0360-4012    

DOI:10.1002/jnr.490030104

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

年代:1977

数据来源: WILEY

摘要:

AbstractIn chloralose‐anesthetized. Flaxedil‐paralyzed cats, the suppression of extralemniscal thalamic units by the dorsal and ventral hippocampus was investigated. Unitary responses to test somatic stimuli, recorded in centrolateral and neighboring thalamic nuclei, were interacted with conditioning electrical stimulation in different regions around the hippocampal arch, including the parahippocampal gyrus (entorhinal and retrosplenial areas).Stimulation of dorsal (DHC) and ventral (VHC) hippocampus suppressed roughly equal proportions of responses. However, within each of DHC and VHC, effectiveness depended on the region stimulated. In DHC, Fields CA1 and CA3, subiculum (SUB), and retrosplenial area, but not field CA4 with dentate gyrus (FD), while stimulation of CA1 or subiculum was almost ineffective at currents below 1.0 mA. In VHC the regions were ranked for effectiveness as follows: entorhinal cortex = CA3>FD>SUB>CAI.No topographic relationship was found between hippocampal region and thalamic loci for unit suppression. Lemniscal‐type unit responses in ventrobasal thalamus were unaffected by stimulation of the hippocampus or parahippocampal gyrus.Interruption of the fornix‐fimbria system prevented suppression elicited from CA1 of DHC or from CA3 of VHC, but not from FD of VHC. It had no effect on suppression elicited from retrosplenial or entorhinal cortex.Hippocampal regional variation of effectiveness in suppressing extralemniscal pathways may contribute to the differential behavioral involvements reported for different hippocampal str

ISSN:0360-4012    

DOI:10.1002/jnr.490030105

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

年代:1977

数据来源: WILEY

摘要:

AbstractGallamine triethiodide, a drug commonly used in neurophysiological experiments, causes statistically significant and inconsistent changes in the information‐carrying capacity of trains of action potentials generated by members of a population of gamma motor neurons recorded from the same cat under the same conditions during the same time perio

ISSN:0360-4012    

DOI:10.1002/jnr.490030106

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

年代:1977

数据来源: WILEY

摘要:

AbstractThe direct neurotoxic effects of E. coli endotoxin (ETX) on spontaneous transmitter release were tested at the frog sartorius muscle neuromuscular junction. Spontaneous transmitter release was monitored by intracellularly recording miniature end‐plate potentials (MEPPs). Junctions were continuously exposed to standard concentrations of 10μg/ml of 3 ETX sample, 2 of which produced a significant elevation of MEPP frequency followed by a decline of frequency to very low rates. The third ETX sample, known to have a decreased canine lethality, was with out effect on MEPP frequency. No significant changes in MEPP amplitude were evident. The rate of change in MEPP frequency, but not the peak frequency, was reduced by lowering ETX concentrations. Alterations in MEPP frequency induced by ETX were prevented by removing Ca++and antagonized by high [k+] out. The results suggest that ETX alters ion conductance channels, particularly those for Ca++, in the presynaptic terminal membra

ISSN:0360-4012    

DOI:10.1002/jnr.490030107

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

年代:1977

数据来源: WILEY

摘要:

AbstractThe relative amounts of incorporation of [3H]lysine into various brain areas and segments of the spinal cord in adult Cebus and Rhesus monkeys were studied. One hour after subcutaneous injection of [3H]lysine, animals were sacrificed and the brain and spinal cord samples taken and processed for3H}lysine incorporation into protein (Lowry et al., 1951; Wells and Bernstein, 1976). Analysis revealed Marked differences in metabolism among brain areas within each species of monkey as well as across species. Cortical structures were generally higher in radioactive uptake than subcortical structures in both species. The Cebus monkey had the greatest variation among brain areas, particularly between cortical regions, whereas the Rhesus monkey did not show cortical variation in uptake. The ratio of incorporated to nonincorporated lysine in the brain and spinal cord was higher in the Rhesus than the Cebus monkey. Both species showed a rostrocaudal gradient of radioactivity following [3H]lysine incorporation into the spinal cord. Considering weight, size, and availability differences, the metabolism of [3H] lysine appears to differ by brain areas and spinal cord segments between species.

ISSN:0360-4012    

DOI:10.1002/jnr.490030108

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

年代:1977

数据来源: WILEY

摘要:

AbstractThe construction and use of a permanent, implanted plastic cannula for intraventricular injections in rat brain is described. The cannula can be used in either acute or chronic experiments.

ISSN:0360-4012    

DOI:10.1002/jnr.490030109

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

年代:1977

数据来源: WILEY

ISSN:0360-4012    

DOI:10.1002/jnr.490030101

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

年代:1977

数据来源: WILEY