Meeting Abstract

P3-40  Monday, Jan. 6  Gonadotropin-Inhibitory Hormone and its Receptor in Zebra Finch Spinal Cord: A Novel Pathway for Neuropeptide Action? COMITO, D*; BENTLEY, GE; University of California, Berkeley; University of California, Berkeley dcomito@berkeley.edu

Gonadotropin-inhibitory hormone (GnIH) is a neuropeptide that typically acts in the hypothalamic-pituitary-gonadal (HPG) axis to inhibit reproductive activity and sociosexual behaviors. GnIH is synthesized in the brain and in the gonads, where it can act via its cognate receptor. However, immunohistological evidence in songbirds also shows GnIH projections towards the brainstem. We investigated the possibility that this neuropeptide might act directly within the spinal cord of zebra finches (Taeniopygia guttata). Using immunohistochemistry, we determined that GnIH-immunoreactive fibers are present throughout the length of spinal cord gray matter, with the majority of the peptide located in the cervical region. Using PCR, we also found mRNA expression of GnIH precursor peptide and GnIH receptor (GnIH-R) throughout the spinal cord. These data raise questions about the potential mechanisms of action and roles of GnIH in zebra finch spinal cord. Our results provide evidence for potentially novel modes of action of GnIH that have implications for physiology and behavior. Current research is exploring modulation of GnIH and GnIH-R in the central nervous system in response to fasting and sickness.