Abstract
Until recently, there were few rodent models available to study the interaction of post-traumatic stress disorder (PTSD) and drug taking. Like PTSD, single prolonged stress (SPS) produces hypothalamic-pituitary-adrenal (HPA) axis dysfunction and alters psychostimulant self-administration. Other stressors, such as isolation stress, also alter psychostimulant self-administration. However, it is currently unknown if isolation housing combined with SPS can alter the acquisition or maintenance of cocaine self-administration. The current study applied modified SPS (modSPS; two hours restraint immediately followed by cold swim stress) to rats raised in an isolation condition (Iso), enrichment condition (Enr), or standard condition (Std) to measure changes in cocaine self-administration and HPA markers. Regardless of rearing condition, rats exposed to modSPS had greater corticosterone (CORT) release and reduced cocaine self-administration during initial acquisition compared to non-stressed controls. In addition, during initial acquisition, rats that received both Iso rearing and modSPS showed a more rapid increase in cocaine self-administration across sessions compared to Enr and Std rats exposed to modSPS. Following initial acquisition, a dose response analysis showed that Iso rats were overall most sensitive to changes in cocaine unit dose; however, modSPS had no effect on the cocaine dose response curve. Further, there was no effect of either modSPS or differential rearing on expression of glucocorticoid receptor (GR) in hypothalamus, medial prefrontal cortex, amygdala, or nucleus accumbens. By using modSPS in combination with Iso housing, this study identified unique contributions of each stressor to acquisition of cocaine self-administration.
Original language | English |
---|---|
Pages (from-to) | 143-152 |
Number of pages | 10 |
Journal | Behavioural Brain Research |
Volume | 338 |
DOIs | |
State | Published - Feb 15 2018 |
Bibliographical note
Publisher Copyright:© 2017 Elsevier B.V.
Funding
This work was supported by National Institute of Health grants [ DA012964 , DA036291 ].
Funders | Funder number |
---|---|
National Institute of Health National Institute of Minority and Health Disparities Loan Repayment Program | DA036291, DA012964 |
Author National Institute on Drug Abuse DA031791 Mark J Ferris National Institute on Drug Abuse DA006634 Mark J Ferris National Institute on Alcohol Abuse and Alcoholism AA026117 Mark J Ferris National Institute on Alcohol Abuse and Alcoholism AA028162 Elizabeth G Pitts National Institute of General Medical Sciences GM102773 Elizabeth G Pitts Peter McManus Charitable Trust Mark J Ferris National Institute on Drug Abuse | F32DA036291 |
Keywords
- Cocaine self-administration
- Environmental enrichment
- Isolation
- PTSD
- Single prolonged stress
ASJC Scopus subject areas
- Behavioral Neuroscience