Noradrenergic involvement in pinealectomy induced convulsions in gerbils.

Gerbils treated with various noradrenergic compounds were pinealectomized (PINX) or sham-operated (SHAM) and observed for convulsive activity. Although declines in cortical and hypothalamic norepinephrine content were found after alpha-methylparatyrosine (alpha MPT) or PINX, treatment with alpha MPT did not produce convulsions in SHAM gerbils or in gerbils which were PINX one week earlier. Likewise, alpha MPT did not increase the number or severity of convulsions observed in acutely PINX gerbils. Treatment with propranolol or isoproterenol did not have any effect on convulsive activity of PINX gerbils, except that isoproterenol increased the excitability of all the gerbils. In conclusion, reducing catecholamine content or modifying beta-noradrenergic receptor activity was not able to alter the convulsive activity which occurs after acute PINX.