Ibogaine is a psychedelic derived from the root bark of Tabernanthe iboga. Despite its therapeutic potential, this alkaloid remains poorly characterized, and its central nervous system (CNS) actions and mechanisms have yet to be fully elucidated.
This research explores the effects of a single ibogaine dose on the protein expression of the early immediate early gene c-fos, used as a marker of activity in the CNS of adult rats. Our study focused on regions involved in processes like reward, memory and behavioral inhibition, such as the medial prefrontal cortex (mPFC), nucleus accumbens (Acb) and amygdala (Amy).
Male adult Wistar rats received an intraperitoneal injection of ibogaine (40 mg/kg) or its vehicle. Behaviors associated with the serotonergic syndrome, characteristic of psychedelic substances, were quantified in an open field for 30 minutes. 60 min later brains were fixed and frozen to collect coronal sections from the regions noted above, and performed immunohistochemistry for the detection of c-Fos. c-Fos positive cells were quantified using ImageJ software.
The psychedelic induced distinctive behaviors, mainly high levels of tremor. Increased c-Fos immunoreactivity was observed in all analyzed mPFC and Amy subregions, while a treatment effect was only seen in the shell of the Acb.
These findings indicate the involvement of mPFC, Acb and Amy in ibogaine’s early actions and provide relevant information on its differential effects in the CNS of the rat.