School of Psychology, Victoria University of Wellington, Wellington, 6011, New Zealand.
Psychopharmacology (Berl). 2018 Nov;235(11):3233-3241. doi: 10.1007/s00213-018-5026-1. Epub 2018 Sep 12.
3,4-Methylenedioxymethamphetamine (MDMA) preferentially increases synaptic serotonin (5HT). This response was attenuated following repeated exposure but there was recovery as a result of abstinence. Effects of abstinence on self-administration of many drugs have been documented but the impact on MDMA self-administration is unknown.
This study compared the effects of abstinence on MDMA and cocaine self-administration.
Six-hour daily MDMA or cocaine sessions were conducted until a total of 350 mg/kg had been self-administered. Following this, rats were randomly assigned to either a 0- or 14-day abstinence group. Self-administration testing then continued for an additional 7 days.
The latency to self-administer 350 mg/kg was shorter for rats that self-administered cocaine. The temporal distribution of responding within each test session also differed; MDMA self-administration was high during the first hour of each session, and decreased during subsequent hours, whereas cocaine self-administration was evenly distributed throughout each hour of the session. Abstinence decreased MDMA but not cocaine self-administration.
The selective reduction of MDMA self-administration following abstinence is consistent with the idea that MDMA-stimulated 5-HT release is inhibitory to MDMA self-administration.
3,4-亚甲二氧基甲基苯丙胺（MDMA）优先增加突触血清素（5HT）。这种反应在反复暴露后减弱，但由于禁欲而恢复。许多药物的禁欲对自我给药的影响已有记载，但对 MDMA 自我给药的影响尚不清楚。
本研究比较了禁欲对 MDMA 和可卡因自我给药的影响。
进行了为期 6 小时的每日 MDMA 或可卡因疗程，直到总共摄入 350mg/kg。在此之后，大鼠被随机分配到 0 天或 14 天禁欲组。然后继续进行另外 7 天的自我给药测试。
自我给予 350mg/kg 的潜伏期对于自我给予可卡因的大鼠来说更短。每个测试会话内反应的时间分布也不同；MDMA 自我给药在前每个会话的第一个小时内很高，随后几个小时内减少，而可卡因自我给药在每个会话的每个小时内均匀分布。禁欲减少了 MDMA 但没有减少可卡因的自我给药。
禁欲后 MDMA 自我给药的选择性减少与 MDMA 刺激 5HT 释放对 MDMA 自我给药有抑制作用的观点一致。
