Effects of diazepam or haloperidol on convulsion and behavioral responses induced by bilateral electrical stimulation in the medial prefrontal cortex

1. Effects of diazepam (DZP) or haloperidol (HAL) on convulsions and behavi oral responses (locomotion, circling, spying and head shaking) induced by b ilateral electrical stimulation in the medial prefrontal cortex (mPFC) were examined. 2. Male Wistar rats were electrically stimulated (ten 30-sec trains, 60 Hz, 80 - 100 mu A) bilaterally in the mPFC and their behavior was simultaneous ly observed in an open field in daily session. 3. DZP and HAL dose-response curves (0, 0.5, 1.25, 2.5 and 5 mg/kg, i.p., 3 0 min before electrical stimulation session) were determined after a baseli ne of behavioral responses was established. 4. DZP dose-dependently decreased head shaking and convulsions, had no effe ct in circling and spying behaviors, and increased locomotion except at the highest dose. HAL reduced locomotion, circling and spying behaviors in a d ose-dependent manner, but did not affect convulsions or head shaking. 5. These results demonstrated that convulsion and behavioral responses indu ced by electrical activation of the mPFC were modified by DZP or HAL. There fore, the mPFC is involved in the mediation of neural and/or behavioral act ivity that may be implicated in some central effects of psychoactive drugs.