Figure 6.

A single pulse of 5HT to the CNS results in a transient sensitization of the T-TWR, while multiple 5HT pulses induce intermediate- and long-term sensitization. Sample T-TWR recordings and summary data showing response amplitude and duration after a single 5-min pulse of 5HT (A) and five 5-min pulses of 5HT (B). Ten minutes after a single pulse of 5HT, or after the first of five pulses of 5HT (data from these two groups were combined for the 10-min analysis), the T-TWR showed an increase in amplitude and shortening of duration that was not present at 1 h or 24 h. After repeated 5HT pulses, the T-TWR expressed sensitization in the form of enhanced response amplitude and lengthened duration at 1 h and 24 h after 5HT. Asterisk (*) indicates P < 0.05.