Neurobiology 

Neuropeptide Y (NPY) is a 36 amino acid peptide neurotransmitter found in the brain and autonomic nervous system. NPY has been associated with a number of physiologic processes in the brain, including the regulation of energy balance, memory and learning, and epilepsy.The main effect is increased food intake and decreased physical activity. NPY is secreted by the hypothalamus, and in addition to increasing food intake, it increases the proportion of energy stored as fat and blocks nociceptive signals to the brain NPY also augments the vasoconstrictor effects of noradrenergic neurons.