The antidepressant and analgesic effects of kratom are accompanied by low frequency oscillations but not DeltaFosB accumulation
Mitragyna speciosa (kratom) is a plant native to Southeast Asia believed to have medicinal properties to improve mood and relieve acute and chronic pain. This study evaluated the dose- dependent effects of a kratom extract on brain systems function and its potential use as an analgesic and antidepressant agent. Rats were administered low or high dose kratom for 7 days and electrophysiological and behavioural testing occurred on the first and final day. Changes in ΔFosB expression were also evaluated. Following acute and repeated administration, kratom induced dose-dependent and region-specific changes in oscillatory power and coherence within the ventral tegmental area, prefrontal cortex, cingulate cortex and nucleus accumbens. Both doses of kratom elicited analgesic effects, evidenced by the tail-flick test, whereas only the low dose had antidepressant effects in the forced swim test. These results suggest kratom induces alterations to neural network activity which may underlie its analgesic and antidepressant effects.