MDMA pretreatment leads to mild chronic unpredictable stress-induced impairments in spatial learning.
Behavioral Neuroscience – October 01, 2009
Source: OpenAlex
Summary
Prior exposure to MDMA significantly impacts learning under stress, as shown in a study with rats. While MDMA alone heightened anxiety-like behavior, chronic unpredictable stress (CUS) did not amplify this effect when combined with MDMA. Notably, MDMA pretreatment resulted in learning impairments during the Morris water maze task, despite no increase in serotonin transporter (SERT) depletion in the hippocampus. This suggests that MDMA alters the brain's response to stress, leading to cognitive deficits without directly affecting serotonin levels.
Abstract
3,4-Methylenedioxymethamphetamine (MDMA) is a drug of abuse worldwide and a selective serotonin (5-HT) neurotoxin. An important factor in the risk of drug abuse and relapse is stress. Although multiple parallels exist between MDMA abuse and stress, including effects on 5-HTergic neurotransmission, few studies have investigated the consequences of combined exposure to MDMA and chronic stress. Therefore, rats were pretreated with MDMA and exposed 7 days later to 10 days of mild chronic unpredictable stress (CUS). MDMA pretreatment was hypothesized to enhance the effects of CUS leading to enhanced 5-HT transporter (SERT) depletion in the hippocampus and increased anxiety and cognitive impairment. Whereas MDMA alone increased anxiety-like behavior on the elevated plus maze, CUS alone or in combination with MDMA pretreatment did not increase anxiety-like behavior. In contrast, MDMA pretreatment led to CUS-induced learning impairment in the Morris water maze but not an enhanced depletion of hippocampal SERT protein. These results show that prior exposure to MDMA leads to stress-induced impairments in learning behavior that is not otherwise observed with stress alone and appear unrelated to an enhanced depletion of SERT.