Fig. 6.

Effects of K252a. A, The kinase inhibitor K252a blocks potentiation and leads to inhibition of synaptic transmission by NGF. In the presence of 200 nmK252a alone, a myocyte showed a normal small elevation in beats per minute in response to stimulation of a connected neuron. However, in the presence of K252a, NGF did not potentiate, and led to a decrease in, the myocyte response to neuronal stimulation. The breaks in thex-axis indicate that myocyte beat rate was not counted during these perfusion periods (10 min for initial perfusion of NGF, 10 min for washout). B, In K252a, NGF reduces synaptic transmission. Averaged, pooled data. On average, in the presence of K252a, NGF induces a significant decrease in the responses of myocytes to neuronal stimulation (p < 0.05; paired Student’s t test; n = 5). Error bars represent SEM.