The study of neuropeptide function in behavioral neuroscience has come a long way since the first neuropeptide, substance P, was isolated in 1931. Following this discovery, many neuropeptides have been discovered and they make up one of the largest classes of chemicals that alter neuronal function [1]. There are some common features among neuropeptide function. Neuropeptide receptors tend to be metabotropic G protein coupled receptors [1]. As a result, neuropeptides typically modulate neuronal activity on a longer time scale than other neurotransmitter classes that act as ligands at ionotropic receptors. Compared to other neurotransmitter types, the release of neuropeptides almost exclusively requires high frequency or burst firing activity [1]. This prerequisite of high signaling input supports the putative functionality of neuropeptides. Neuropeptides play a key role in homeostatic regulation – from food intake to stress response to alertness [1]. In summary, when the organism is challenged in ways of energy balance, stress, and pain, neuropeptide signaling is likely involved.

There has been increasing recognition of neuropeptides in another physiological challenge: repeated exposure to a drug reward. With accumulating evidence, it has become apparent that the same neuropeptide circuits involved in homeostatic regulation also govern the response to drugs of abuse. Neuromedins, a newer neuropeptide subclass isolated from porcine spinal cord in 1985, has been posited to have a role in drug motivated behavior. Initially, in the history of neuromedin U (NMU) specifically, its function was attributed to muscle contraction, anorexia, thermogenesis, and nociception response [2]. To add to the repertoire of NMU functionality, the report by Kasper et al. [3] in this issue of Neuropsychopharmacology highlights the role of NMU in regulating cocaine self-administration, and they investigate the function of NMU on multiple dimensions: behavior, circuit, and cell-type.

Log in or create a free account to read this content

Gain free access to this article, as well as selected content from this journal and more on nature.com

Access through your institution

or

Sign in or create an account
Continue with Google
Continue with ORCiD