[Pharmacological actions on the activity of muscle spindles induced by electrostimulation of the pericruciate cortex in the cat].
In anesthetized cats, effects of a number of neuroactive substances on results of local electrical stimulation of the motor (field 4) and supplementory motor (field 6) cortex were studied in intra - and extrafusal elements of the foot flexors. Flaxedil in subparalytic doses blocked selectively the contractions of extrafusal fibers whereas facilitating effects on activity of muscle afferents from the fields 4 and 6 were preserved which attests a possibility of cortical regulation of the gamma-system irrespective of alpha-motoneurons. Nembutal (5 mg/kg) rapidly suppressed the cortico-fugal excitatory effects which was easily opposed by bemegride. Aminasine (3-5 micrograms/kg) completely and for a long time blocked the cortical-motoneuronal influences. The cortico-reticular projections, anatomically well developed in cats, are supposed to be an essential component of the systems originating in the field 4 and particularly field 6.
D000818:Animals; D001534:Bemegride / Q000494:pharmacology; D002415:Cats; D002746:Chlorpromazine / Q000494:pharmacology; D003714:Denervation; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D005703:Gallamine Triethiodide / Q000494:pharmacology; D009044:Motor Cortex / Q000502:physiology*; D009470:Muscle Spindles / Q000187:drug effects* / Q000502:physiology; D009132:Muscles / Q000294:innervation; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology; D010424:Pentobarbital / Q000494:pharmacology
D001534:Bemegride; D010424:Pentobarbital; D005703:Gallamine Triethiodide; D002746:Chlorpromazine
Farmakologicheskie vozdeĭstviia na aktivnost' myshechnykh vereten, vyzvannuiu élektrostimuliatsieĭ perikrutsiatnoĭ kory u koshki.