Human behavior is determined by the brain. The function of the brain relies on connections between various types of neurons. The main form of communication between neurons is via the so called synapses. The number and type of synapses between neurons are determinants of behavior. Thus, we hypothesize that altered behavior in people with PWS is due to altered communication (synapse quality and number) between distinct neurons. We also believe that a hormone in the blood, ghrelin, which is known to be elevated in PWS patients, is responsible for this altered communication between neurons. Our proposal will test whether such altered communications between neurons indeed exist in the brains of people affected by PWS using post-mortem tissues derived from humans. We believe that his data will open new avenues for developing novel therapeutic strategies to combat symptoms of PWS.