Regulation of seasonal reproduction by neurotransmitter affecting drugs in spotted munia, Lonchura punctulata

Abstract

Timed daily injection of serotonin precursor, 5-HTP (5-Hydroxytryotophan) and dopamine precursor, L-DOPA (Dihydroxyphenylalanine) determine seasonality in wild finch spotted munia. Lonchura punctulata, which does not utilize photoperiod to tune their seasonal reproduction. These effects are due to serotonergic and dopanunergic activities and not due to serotomn and dopamine alone. Further, L-DOPA was effective when converted into dopamine and not into nor-adrenaline or adrenaline, the next biosynthetic product of dopamine. The findings suggest that seasonal changes in the reproductive functions may be related to seasonal changes in the phase relationship between daily rhythms in serotonergic and dopaininergic activity in the central nervous system.