The role of biogenic amines in the reserpine-induced alteration of minimal electroshock seizure thresholds in the mouse

It is suggested that NE and 5-HT, but not DA, are important in regulating minimal electroshock seizure susceptibility, and the return to normal seizure susceptibility correlated well with the return of the ability of whole brain tissue to synthesize and retain3H-amine formed from either 3H-3,5-l-tyrosine or 3H -5-hydroxy-dl-tryptophan.

Abstract

A single injection of reserpine (1 mgkg i.p.) produced an increased susceptibility to minimal electroshock seizures, as well as a decrease in whole brain levels of norepinephrine (NE), dopamine (DA), and serotonin (5-HT). The return to normal seizure susceptibility correlated well with the return of the ability of whole brain tissue to synthesize and retain 3H-amine formed from either 3H-3,5-l-tyrosine or 3H-5-hydroxy-dl-tryptophan. Selective inhibition of catecholamine synthesis with α-methyl-p-tyrosine, following reserpine administration, prevented the return to normal both of seizure susceptibility and NE and DA levels. The combination of disulfiram and reserpine also prevented the return to normal seizure susceptibility. After the latter treatment, levels of DA were elevated while NE remained depressed. Selective inhibition of 5-HT synthesis following reserpine similarly prevented the return of normal seizure susceptibility. Our study suggests that NE and 5-HT, but not DA, are important in regulating minimal electroshock seizure susceptibility.