PREFRONTAL CORTEX SELF-STIMULATION AND ENERGY-BALANCE

The relation between sulcal prefrontal cortex (SPC) and medial prefrontal cortex (MPC) self-stimulation and energy balance was investigated in rats. SPC but not MPC self-stimulation induced feeding but not the gnawing of wooden blocks. SPC but not MPC self-stimulation enhanced weight gain over several weeks of exposure to stimulation. Food deprivation (48 hr but not 24 hr) increased SPC self-stimulation rates under a 5-s fixed-interval reinforcement schedule and decreased current thresholds for SPC self-stimulation. MPC self-stimulation was unaffected by food deprivation. Insulin (4 U/kg) and 2-deoxy-D-glucose (300 mg/kg) inhibited both SPC and MPC self-stimulation, probably through interfering with performance. Satiety induced by prolonged intake of a sweetened solution or deprivation-induced feeding moderately facilitated SPC self-stimulation. Overall, it appears that SPC but not MPC self-stimulation modulates, and is modulated by, energy balance.