SLEEP-DEPRIVATION IS A LESS POTENT AGENT THAN CLOMIPRAMINE IN INCREASING FIRING RATE IN LATERAL SEPTAL NEURONS IN THE RAT

Acute injection of clomipramine or a 24-hour period of sleep deprivation produces an increased firing rate in lateral septal neurons of the rat. However, it is unknown whether changes in firing rate in lateral septal neurons also appear after repetitive treatments. This study explored and compared the effects of long-term clomipramine with those of sleep deprivation from 1 to 4 days in the firing rate of lateral septal neurons. The firing rate increased after both treatments; however, maximal effects occurred on different days. Clomipramine (1.25 mg/kg, i.p., twice a day) produced a stable, increased firing rate after 20 days of treatment. Twenty-four hours of total sleep deprivation produced changes in firing rate comparable to 10 days of clomipramine treatment. Changes in firing rate did not appear when animals were exposed to 12 h of sleep deprivation alternated with 12 h in housing cages. Therefore, it is concluded that 24 h of total sleep deprivation is a less effective treatment than clomipramine for producing changes in firing rate in lateral septal neurons.