Figure 8. Chronic activation of CB2Rs in intact mice enhances excitatory synaptic transmission.

A, field excitatory postsynaptic potentials (fEPSPs) were recorded from the CA1 stratum radiatum in acute hippocampal slices of C57BL/6J mice. Input–output (I/O) curves of fEPSPs were constructed from the rising slope of fEPSP against the amplitude of the presynaptic fibre volley. Mice were injected with JWH133 (5 mg kg⁻¹, i.p.) or vehicle once per day for 7–9 days. Acute hippocampal slices were made 24 h after the last injection. Each line represents one slice. B, the mean slope of the I/O curves was obtained from linear regression of individual I/O curves shown in A. *P = 0.0008, Student's unpaired t test. C and D, experiments were done as in A and B, but acute hippocampal slices were made from CB2R KO mice injected with JWH133 (5 mg kg⁻¹, i.p.) or vehicle once per day for 7–9 days.