Harmine impairs memory performance of treated rats and nontreated cagemates.
Experimental and Clinical Psychopharmacology – November 04, 2021
Source: OpenAlex
Summary
Harmine, a key component of Ayahuasca, significantly impairs memory performance in rats. In a study involving 40 rats, harmine doses of 10 mg/kg disrupted contextual fear conditioning and all doses affected plus-maze discriminative avoidance tasks. Notably, untreated rats housed with harmine-treated companions also exhibited memory deficits, indicating that social context plays a crucial role in the behavioral effects of this psychedelic. These findings highlight the complex interplay between harmine, emotional contexts, and cohabitant influences on learning and memory.
Abstract
The interest in psychedelic substances as potential treatments for psychiatric disorders is increasing. The β-carboline harmine, an Ayahuasca component, presents hallucinogenic and antidepressant effects. Although Ayuahuasca-and consequently harmine-is usually consumed in rituals, the role of social contexts in the behavioral effects of harmine has not been investigated yet. In this sense, affective states may modulate cohabitants' behavior, including learning/memory. This work investigates the effects of harmine on the learning/memory performance of rats evaluated on the contextual and tone fear conditioning (CFC and TFC) and on the plus-maze discriminative avoidance (PMDAT) tasks. The possible influence of a harmine-treated cohabitant was assessed by evaluating rats housed in homogeneous cages-where all the animals were acutely administered with the same treatment (vehicle, 5, 10, or 15 mg/kg harmine), and in heterogeneous cages-where each animal received a different drug treatment. The main results are: (a) harmine impaired CFC (10 mg/kg) and PMDAT discrimination (all doses); and (b) harmine caused a memory deficit in CFC, TFC, and PMDAT of untreated rats kept in heterogeneous cages. Our results show that harmine induces a memory deficit in tasks with emotional contexts. Further, the cohabitation with animals treated with this drug also seems to impair memory performance of untreated animals. (PsycInfo Database Record (c) 2022 APA, all rights reserved).