[The effect of serotonin on flash visual evoked potential in the rat prenatally exposed to cadmium]

The purpose of this paper was to find out any influence of cadmium (Cd) on the effect of serotonin (5-HT) in the central nervous system (CNS).

18 Wistar albino strain female rats were divided into 3 groups: 6 received 5 ppm, 6 one 50 ppm cadmium in tap water since time of conception and during next 21 days after delivery. Control group of 6 rats received tap water only. Newborns were examined when they were 3 to 6 months old. Flash visual evoked potential (FVEP) was recorded before and after injection of 10 microliters saline and then 5-HT into the right lateral brain ventricle. Two doses of 5-HT 125 and 250 nmols were used. Amplitudes of the first deep negative wave (N1) and the next positive one (P1) were measured from isoelectric line to peaks. For statistic analysis the t-test of Student was used with statistical significance by p < 0.05.

Shortened latencies (89-99%) of the peaks N1 and P1 of FVEP in the control and Cd 50 ppm groups after both doses of 5-HT were observed, however, they slightly prolonged (103-105%) in the Cd 5 ppm group. The highly significant increase of amplitude of the waves N1 and P1 in all observed groups was received. The only differences were observed in the Cd 5 ppm group; the amplitude of P1 peak was of the same value (100-101%) after 125 nmols and decreased (91%) after 250 nmols of 5-HT compared to the initial values in this group.

Cadmium increases the serotonin sensibility in the CNS.