Figure 2.

The effects of intracerebroventricular administration of the CB1 receptor antagonist, AM‐251, and leptin, and their interaction, on the mean spike frequency of penicillin‐induced epileptiform activity. (A) AM‐251, at a dose of 0.25 μg (i.c.v.), increased the mean spike frequency of epileptiform activity within 30 min after AM‐251 injection. The administration of leptin (1 μg, i.c.v.) increased the frequency of epileptiform activity in the 80 min after leptin injection. The administration of leptin (1 μg) 10 min before AM‐251 (0.25 μg) significantly increased the mean spike frequency of epileptiform activity compared with penicillin and leptin injected group. The proconvulsant activity appeared within 40 min after leptin injection. (B) AM‐251, at a dose of 0.125 μg (i.c.v.), did not influence the mean frequency of epileptiform. The administration of leptin (1 μg) 10 min before AM‐251 (0.125 μg) enhanced the proconvulsant activity of AM‐251 (0.125 μg). The proconvulsant activity appeared in the 40 min after leptin injection. *P < 0.05, **P < 0.01, ***P < 0.001. The percentage frequency of epileptiform ECoG activity value depends on both the frequency of epileptiform ECoG activity before and after the substance administered as it is defined as follows:

$$\mathrm{Frequency}\mathrm{Value}\mathrm{\%}=\frac{\mathrm{The}\mathrm{mean}\mathrm{of}\mathrm{spike}\mathrm{frequency}\mathrm{after}\mathrm{substance}\mathrm{administered}}{\mathrm{The}\mathrm{mean}\mathrm{of}\mathrm{spike}\mathrm{frequency}\mathrm{before}\mathrm{substance}\mathrm{administered}}\times 100$$