Fig. 4. Bar graphs demonstrating the effects of 5-HT on evoked spikes by subtracting the number of spikes evoked during 5-HT application from the preceding control period. A, A significant effect of dose is seen in the number of spikes evoked by glutamate during 5-HT application. In the intact, ADX plus 5 mg of CORT, and ADX plus 10 mg of CORT groups, there is a large decrease in the number of spikes evoked during 5-HT application. However, in the ADX group, very little difference is seen between the control and 5-HT application period, and in the ADX plus 1 mg of CORT group, there is a trend toward an increase in the level of activity. B, In the MGm-stimulated neurons, a significant effect of dose is also seen in the number of spikes evoked during 5-HT application. In the intact, ADX plus 5 mg of CORT, and ADX plus 10 mg of CORT groups, a large decrease in the number of spikes evoked during 5-HT application is seen. However, in the ADX and ADX plus 1 mg of CORT groups, very little difference is seen between the control and 5-HT application period.C, Of the neurons activated by TE3 stimulation, there was not a significant effect of dose. However, this is because of the large degree of variance in the 10 mg of CORT group. The overall pattern of responses is similar to the glutamate and TE3 groups, with only the intact, ADX plus 5 mg of CORT, and ADX plus 10 mg of CORT groups showing a decrease in the number of spikes evoked during 5-HT application. *p < 0.05