Figure 1.

5-HT_1A receptor activation depresses naïve synaptic responses. (A) Normalized data showing the effect of 5-CT/clozapine on the amplitude of evoked synaptic responses in both older and younger animals combined (n=12). The horizontal bar indicates the timing of the drug application. Note that the amplitudes of the synaptic responses are only partially reversed following washout of 5-CT/clozapine. The values for normalized data are presented as the mean+s.e.mean. (B) Examples showing the 5-CT/clozapine-induced depression of epsps observed in neurons obtained from P3 – 6 (63%) and P10 – 14 (50%) animals respectively. (C) Application of the 5-HT_1A/7 receptor agonist 5-CT in the presence of the 5-HT_1A receptor antagonist NAN-190 facilitated e.ps.p amplitude (52%). (D) Example of a cell where the 5-HT_1A receptor agonist 8-OH-DPAT depressed the evoked e.p.sp. In this and the following similar figures, the individual raw traces of the control synaptic responses are superimposed in black, while the raw traces in the presence of the ligands are superimposed in grey. Averaged synaptic actions are presented to the right.