Interaction between serotonin and a dopamine precursor (given 8 hour apart) and luteinizing hormone alters reproductive and metabolic responses of migratory red headed bunting(Emberiza bruniceps)

Abstract

Abstract During the progressive phase of the seasonal breeding cycle four groups of male buntings were treated with (i) Normal saline (control), (ii) Luteinizing hormone (LH), (iii) L‐Dihydroxyphenylalanine (L‐DOPA, a dopamine precursor) given 8 hr after 5‐Hydroxytryptophan (5‐HTP, serotonin) (8‐hr relationship) and (iv) LH and these neurotransmitter precursor drugs with the same temporal relationship (LH + 8 hr). The results indicate that at the end of the study, while the controls as well as the LH treated birds exhibited full breeding condition (although its degree of development was higher in the latter), the testes of birds of the “8‐hr group”; showed complete atrophy. But, the birds receiving both treatments (LH + 8 hr) were not different from the controls. The body weight responses of the birds followed the same pattern as those of testes weight. It is suggested that the phase relationship of serotonergic and dopaminergic drugs controls the reproductive (gonadal activity) and metabolic (body weight...