Corticospinal influences on primary afferents during sleep and wakefulness

Riassunto Nel sonno desincronizzato si osserva un aumento della scarica piramidale originante dalle aree somato-sensoriali della corteccia in corrispondenza dei REM. Queste scariche piramidali depolarizzano le fibre afferenti primarie della via riflessa flessoria e verosimilmente contribuiscono alla depressione fasica dei riflessi polisinaptici che si manifesta durante i REM.

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This investigation was supported by PHS research grant NB-02990-04 from the National Institute of the Neurological Diseases and Blindness, N.I.H., Public Health Service (USA).     

Über den Einfluss von Desoxycorticosteron auf Kontraktur und Kaliumfreisetzung durch Acetylcholin an der innervierten und denervierten Skelettmuskulatur

Summary The release of potassium ions from striated muscle, and the changes in mechanical tension developed by the gastrocnemius muscle on intraarterial injection of ACh, were investigated by isolated perfusion of the hind limbs in cats. The reaction of the normal innervated and chronically denervated muscle in the same animal were compared before and during perfusion with 2·10^–4 M/l desoxycorticosterone glucoside (DCG). The following results were obtained: after perfusion with DCG no change in the spontaneous release of potassium ions occurred neither on the innervated nor on the denervated muscle. The potassium release following intra-arterial injections of various doses of ACh was significantly reduced on innervated and denervated muscle. On the denervated muscle there was also a considerable reduction of the height of contractures caused by ACh administration. The results make it probable that DCG acts by an inhibition of depolarisation in the same way asd-tubocurarine.