Abstract
Background: Methamphetamine (METH) use has increased substantially in the last 10 years and poses a serious health concern, especially for young populations. Drug abuse primarily begins during adolescence, when uninhibited and excessive and drug intake is a common occurrence; thus, understanding the developmental patterns of addiction during this critical period is an essential step in its prevention. In the present study, the effect of age on the vulnerability to METH abuse was examined using a rat model of bingeing (i.e., escalation). Methods: Adolescent and adult rats were compared during short (ShA, 2-h) and long-access (LgA, 6-h) to METH self-administration. On postnatal (PN) days 23 (adolescents) and 90 (adults), rats were implanted with i.v. catheters and trained to lever press for infusions of METH (0.05. mg/kg) during 2-h sessions. Once the rats reached a steady rate of METH self-administration, they were divided into ShA or LgA groups and allowed to self-administer METH for 15 additional days. Results: Results indicated that adolescent rats earned significantly more infusions than adults under the LgA condition, but the age groups did not differ during ShA. Adolescents, but not adults, also significantly increased (i.e., escalated) METH self-administration across the 15 days of testing under the LgA condition. Further analysis indicated excessive responding during infusions in the LgA METH-exposed adolescents compared to the other groups, suggesting elevated impulsivity or motivation for drug. Conclusion: These results demonstrate that adolescents are more vulnerable to the escalation of METH than adults during LgA.
Original language | English (US) |
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Pages (from-to) | 149-153 |
Number of pages | 5 |
Journal | Drug and alcohol dependence |
Volume | 124 |
Issue number | 1-2 |
DOIs | |
State | Published - Jul 1 2012 |
Bibliographical note
Funding Information:This research was supported by the National Institute on Drug Abuse (NIDA) grants R01 DA003240 , R01 DA019942 , and K05 DA015267 (MEC). NIDA had no further role in the study design; in the collection, analysis, and interpretation of data; in writing; nor in the decision to submit the manuscript for publication.
Keywords
- Adolescence
- Bingeing
- Escalation
- METH
- Rat