Classically Conditioning Morphine Response Profile to Reduce Behavioral Dependence Withdrawal in Male Sprague-Dawley Rats

Cullinan, Stephen

Classically Conditioning Morphine Response Profile to Reduce Behavioral Dependence Withdrawal in Male Sprague-Dawley Rats

Persistent URL

https://dspace.allegheny.edu/handle/10456/56641

Author(s)

Cullinan, Stephen

Date Issued

April 12, 2023

Abstract

The opioid epidemic continues to worsen across the United States. As more individuals continue to fall victim to substance use disorders, it is becoming even more paramount that we identify possible therapies to help those struggling towards rehabilitation. This study aimed to determine whether utilizing both contextual and discrete cues through classical conditioning could be a viable method to reduce withdrawal symptoms both during and after rehabilitation. Twice daily 10 mg/kg subcutaneous morphine administration were given to male Sprague-Dawley rats until behavioral tolerance thresholds were met as measured by responding for water in operant chambers. Withdrawal symptoms were measured based on changes in completed lever response sets, grooming behaviors, defecation amount, and weight — compared to baseline measures prior to drug exposure. Three groups were maintained for this study: a no-cue control which received no exposure to the conditioned stimuli (CS) during withdrawal, a context-cue-only experimental group which was only exposed to the contextual CS of the injection room, and an all-cue experimental group which was exposed to both the contextual CS and received a saline injection functioning as the discrete CS. Statistical analysis indicated a significant difference in grooming behaviors between the three cue groups (p < 0.001), across the five days of withdrawal (p = 0.008), as well as an interaction between them (p = 0.014). Significant differences were also found across the days of the withdrawal phase in completed response sets, defecation, and weight; with weight also having a significant difference between the three cue groups. These three measures, by the end of the 5 days, returned close to their baseline values. These changes across the days indicated a reduction of withdrawal across the five days, suggesting a longer tolerance phase was necessary. These results indicate separate levels of success in conditioning procedures reducing symptoms between the forms of withdrawal being measured. Such conclusions call for more withdrawal symptoms to be explored in future studies.

Major

Neuroscience

Psychology

Honors

Neuroscience, 2023

Psychology, 2023

First Reader(s)

Clark, Rodney D.