Substance abuse disorders have a devastating impact on individuals, families, and society. Present pharmacological treatments do not fully ameliorate patients' symptoms and in many cases are unable to treat the full spectrum of symptoms. Therefore, it is paramount to identify new targets for pharmacological intervention. To do this we must better understand the neural mechanisms underpinning drug-taking behavior and drug-mediated reward. The Neuropeptide S (NPS) system when activated in mice enhances memory formation and produces both anxiolytic-like and hyperlocomotor effects. This is a unique behavioral profile, and if pharmacologically targeted could have multiple therapeutic benefits. Based on research conducted in our lab, we have identified the first and only biased NPSR agonist (RTI-263). It retains full agonist properties in calcium mobilization assays, but has attenuated ability to increase cAMP levels. Importantly, in mice, RTI-263 evokes similar anxiolytic-like and memory enhancing effects as NPS. However, RTI-263 is unable to produce the pronounced increase in locomotor activity and actually blocks hyperlocomotion induced by exogenously administered NPS. Other compounds that block this hyperlocomotion, NPSR antagonists, are known to reduce cocaine seeking in rodents. Therefore, we hypothesize that RTI-263 will display dual properties whereby it will likely simultaneously produce anxiolysis and curb cocaine intake. This has obvious benefit as relapse into the cycle of drug taking in humans is often associated with stress and anxiety producing life events. The goals of this project are to better elucidate the circuitry of the NPS-system by determining the role of particular subpopulations of NPSR-expressing neurons in core behaviors it is known to modulate. In addition, we will show proof-of-concept that NPSR ligands with similar pharmacological profiles as RTI-263 have potential as therapeutics for cocaine abuse. NPSR is a potential target for the development of therapeutics for addiction and other neuropsychiatric disorders related to the dysregulation of stress and anxiety.
Addiction to psychostimulants, such as cocaine, produces a myriad of negative effects and societal consequences. Currently, therapies to treat cocaine addiction are limited to behavioral therapies, with no approved pharmaceutical treatments available. Our research aims to understand the role of a novel brain system that could be targeted to treat cocaine, and perhaps other psychostimulant dependence and drug seeking behavior.