Fig. 7.

Activity blockade increases pyramidal neuron firing rates. A, Representative current-clamp recordings of spontaneous firing from pyramidal neurons grown in control medium (CONTROL), in medium supplemented with 0.1 μm TTX for 2 d (TTX), or in medium supplemented with TTX and BDNF (25 ng/ml) for 2 d (TTX + BDNF). B, Average spike frequency of pyramidal neurons grown for 2 d under the conditions described inA or in TTX + 50 ng/ml NGF (TTX + NGF) or TTX + 25 ng/ml NT3 (TTX + NT3); *significantly different from TTX (Student’s t test,p < 0.01).