STRESS AND BRAIN HISTAMINERGIC SYSTEM - EFFECTS OF WEAK ELECTRIC FOOT-SHOCK

A weak electric foot-shock stressful stimulus (0.5 mA x 1 s x 5 times) significantly increases plasma corticosterone (CS) levels and modifies [H-3]-histamine ([H-3]-HA) binding site constants related to H-2 receptors in rat cortical membranes. Progressive and total recovery of basal binding characteristics occurs 90 min later. A double-foot-shock stress procedure delays [H-3]-HA binding characteristic recovery instead of strengthening stress effects. This finding is further evidence of involvement of the brain's histamine receptors in the response to mild stress.