[Effect of a brain extract containing the postural asymmetry factor on the frog neuromuscular synapse]

The influence of the rat brain extract containing a postural asymmetry factor on the synaptic transmission in the right and left preparations of the frog cutaneus-pectoralis muscle was studied. The extract (2.10(-4) mg/ml) increased the quantal content of end-plate potentials (e.p.p.) in synapses of the right muscle and decreased it in synapses of the left muscle. In both right and left muscles relative changes in quantal content of e.p.p. correlated with relative changes in binomial parameter n. The results indicate an asymmetrical influence of the extract containing a postural asymmetry factor on the transmitter release in synapses of the right and left muscles.