Regulation of feeding behavior and plasma testosterone in response to central neuropeptide Y administration in a songbird

Abstract

In mammalian and avian model species, neuropeptide Y (NPY) simultaneously promotes feeding behavior and suppresses the secretion of reproductive hormones, thereby modulating the resource allocation trade-off between investing in essential somatic processes or in the reproductive system. Investigations into this dual role of NPY in birds have focused on domesticated species and, to our knowledge, no study has examined this role in songbirds. We determined whether NPY treatment acutely regulates feeding behavior and activity of the reproductive system in a male songbird, the Abert's Towhee, Melozone aberti. Intracerebroventricular (ICV) administration of NPY promoted behaviors associated with feeding (decreased latency to initiate pecking in the food bowl, increased number of feeding bouts following treatment, and increased number of pecks into the food bowl during each feeding bout), and it stimulated hopping and drinking behavior. By contrast, we found no effect of NPY treatment on plasma testosterone secretion 60 min after treatment. These results suggest that in male Abert's Towhees NPY stimulates feeding behavior, but provide no evidence that this peptide concurrently influences testosterone secretion.