Figure 4.

Low concentration of DHPG induces population burst firing in Fmr1^−/y slices that depends on eCBs. A, Field recording of activity induced by 5 μm DHPG in CA3 stratum pyramidale of an Fmr1^−/y mouse hippocampal slice. B, Responses of an Fmr1^−/y slice preincubated with the CB₁R antagonist SR141716A to DHPG and PTX. Note the DHPG-induced strong single-unit discharges, but absence of burst firing, before PTX application. C, Interspike intervals of the burst discharges in slices. D, Probability of DHPG-induced burst discharges in slices under different conditions. Blockade of CB₁Rs greatly suppressed the epileptic activity in both Fmr1^−/y and CT-treated WT slices. SR, SR141716A. *p < 0.05, **p < 0.01.