Intranasal Administration of Neuropeptide Y in Healthy Male Volunteers

There is growing evidence that neuropeptides act as neuronal messengers in the brain and have diverse functions that may include the regulation of mood and behavior. For example, neuropeptide Y (NPY) is thought to play a role in the adaptive stress response. The therapeutic application of neuropeptides for psychiatric disorders has been limited by difficult and unreliable penetration of the blood-brain barrier (BBB). However, recent data suggest that intranasal administration may provide a means of effectively delivering some of these neuropeptides to the brain. Thus far it is unclear if this is the case for NPY. The aims of this project are: 1. To evaluate, in 15 healthy male volunteers aged 25-45, the effect of intranasal NPY administration (0, 50 and 100 nmol) on its levels in cerebrospinal fluid (CSF), measured by means of lumbar puncture using an intraspinal catheter between L4 and L5, and in plasma, measured using an intravenous catheter in the forearm. One of the three treatments will be administered to each participant in a double-blind fashion. The 0 nmol condition will serve as the placebo control. 2. To test the effect of intranasal NPY administration on mood and anxiety.