Fig. 2.

Serotonin decreases excitability of primary auditory cortex (A1) neurons in normal rats. A: voltage responses of an example neuron to 100 pA depolarizing current steps. The current protocol is shown below the voltage traces. Dashed gray lines indicate resting membrane potential. B: number of spikes evoked by depolarizing current injections for a population of neurons in aCSF (closed circles) and in presence of 50 μM 5-HT (open circles). Serotonin decreased the number of spikes for currents just above threshold. Error bars are 1SE. C: serotonin did not affect the mean resting membrane potential of neurons. D: serotonin significantly reduced the mean input resistance of neurons. E: serotonin significantly decreased the adaptation ratio of neurons. Horizontal lines in C, D, and E show the mean of each group. Statistical significance: *P < 0.05.