Cold Water Stress Abolishes Hyperactivity Produced by Cortical Suction Lesions Without Altering Noradrenergic Depletion

The effect of forced cold water (15 °C) swimming on catecholamine depletions and behavioral hyperactivity produced by focal right hemispheric cortical suction lesions was assessed. Through the 30-day postoperative period, lesion and sham-operated control animals were placed in cold water for 5 min either four times at weekly intervals, once during the first postoperative week, or not at all. The effect of this cold water swim test was different for lesion and control animals. Stress at weekly intervals produced hyperactivity in control animals, but weekly stress in animals with focal suction lesions blocked the development of their expected hyperactivity. A single stress experience, 1 week postoperative, was also sufficient to block the development of hyperactivity in the lesion group. Stress, although affecting behavior, did not alter the pattern of norepinephrine depletions in animals receiving right hemispheric cortical suction lesions.