Novel Animal Model of Sudden Reduction of High Social Enrichment Demonstrates Behavioral and Neurochemical Validity for Addiction

Authors: Yuki Watanabe, Deborah Kreiss, Pierce Goodeve

SUNY Campus: Binghamton University

Presentation Type: Poster

Location: Old Union Hall

Presentation #: 52

Timeslot: Session A 9:00-10:00 AM

Abstract: Addiction is a behavioral condition characterized by reinforcement, repetition, and compulsion that affects millions of Americans each year. Rates of addiction increased following social restrictions associated with the COVID-19 pandemic. The study aimed to assess the validity of a novel animal model that was designed to simulate the effect of reduced social enrichment on addictive-like behaviors and neurochemistry. Male (n=28) and female (n=28) rats were habituated to high social enrichment for ~5 weeks (Day 33-73). Thereafter, experimental rats were reduced to standard social enrichment for ~4 weeks (Day 74-112) and control rats continued high social enrichment. High social enrichment consisted of ‘playdates’ with 13 other rats, frequent researcher handling, and housing in larger cages with multiple toys. Standard enrichment consisted of no playdates, and minimal handling. Addictive-like behaviors analyzed were arm choice in an elevated T-maze and grooming in an open field. The ventral striatum and prefrontal cortex were targeted as they mediate reward and behavioral routine. Addictive-like neurochemicals (dopamine, serotonin, norepinephrine, 3,4-dihydroxyphenylacetic acid (DOPAC), and 5-hydroxyindole-3-acetic acid (5-HIAA)) were analyzed using high performance liquid chromatography (HPLC) in conjunction with a newly utilized automated analysis technique. Reduced social enrichment increased repetitive arm choices and grooming in both sexes, showing strong behavioral face validity for the study’s animal model. Dopaminergic changes in the prefrontal cortex provided additional support for validity. In addition, reduced social enrichment induced sex differences in both behavioral and neurochemical measures. This model shows promising translational value for researching new therapeutic avenues for human addiction.