ACTION OF CURARE-LIKE DRUGS ON SHORT AND LONG NEURONAL CIRCUITS,

A curare-like non hyperpolarizing drug, such as succinylcholine, seems to produce an overall facilitation on the nervous centers, involving especially long neuron 1 circuits polysynaptic spinal reflex activity, rotary afterdischarges of the cerebellar cortex. On the oligosynaptic arc the facilitatory effect was limited to the very beginning of the administration of the drug, being followed later by inhibition. A hyperpolarizing cucare drug, on the contrary, seems to induce a suppressory action on long interneuronal circuits such as those involved in the response of the cerebellar activity to a gravitational stimulation of the labyrinth. The increase of spinal reflex responses induced in a first time by this drug, seems to contradict the preceding statement such an effect, however, may be due to a more marked blocking effect on the Renshaw inhibitory cells the Renshaw antidromic inhibition is in fact substantially decreased under the action of this drug. Author