[Synaptic effects evoked in the spinal cord motor neurons of the frog by adequate stimulation of muscle spindles].

Monosynaptic EPSPs in motoneurones of isolated spinal cord of the frog Rana ridibunda elicited by stretch of the m. sartorius occurred when the involvement of tendon and leaf-like receptors had been excluded. These EPSPs consisted of two components, the first of which persisted in Ca2+-free, Mn2+ or Mg2+-containing media whereas the second one was completely blocked. These observations are in agreement with electrical nature of the first component and chemical nature of the second one.