The distinction that once separated the nervous and endocrine system is becoming increasingly blurred. Attention is now being focused on hormones as neuromodulators. Since neurons communicate by means of neurotransmitters released at the synaptic terminals, it is important to examine how hormones interact with or modulate this process. Dr. Raible is examining this relationship. She has found that a neuropeptide, alpha- melanocyte stimulating hormone (MSH), produces both a short term (same day) and long term (one week later) inhibition of steroid- induced reproductive behavior. Interestingly, MSH, which is released during cervical stimulation, is thought to be involved in the induction of pseudopregnancy. Dr. Raible will systematically examine the role of ovarian steroid hormones (estrogen, progesterone) and the neurotransmitter, serotonin, in mediating the inhibitory effects of MSH. These results will increase our knowledge of hormone-neurotransmitter-peptide interactions in modulating reproductive states. Elucidating the physiological mechanisms underlying the inhibition of reproductive behavior will lead to a better understanding of infertility and, thus, contribute to the development of successful methods of treatment.
