After a period of forced abstinence, rats treated with the norepinephrine neurotoxin DSP-4 still exhibit preserved food-seeking behavior and prefrontal cortex fos-expressing neurons

Abstract

Aims: Relapse is a common characteristic of compulsive behaviors like addiction, where individuals tend to return to drug use or overeating after a period of abstinence. PFC (prefrontal cortex) neuronal ensembles are required for drug and food-seeking behaviors and are partially regulated by Norepinephrine (NE). However, the contributions of neuromodulators, such as the adrenergic system, in food-seeking behavior are not fully understood. Main methods: To investigate this, we trained male and female rats to press a lever in an operant chamber to obtain banana-flavored food pellets for ten days. We then administered DSP-4 (N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine hydrochloride), a neurotoxin that diminishes norepinephrine levels in the brain. The rats were kept in their home cages for ten more days before being returned to the operant chambers to measure food-seeking behavior. Key findings: Despite receiving DSP-4, the PFC neuronal ensembles measured by Fos and food-seeking behavior did not differ between groups, but rather sex. Significance: Although both NE and Fos expressing neurons are implicated in food-seeking, they do not seem to be involved in a cue-contextual induced re-exposure response.

Keywords

• Norepinephrine
• Fos
• Food
• Prefrontal cortex
• Re-exposure