Ibogaine, a psychedelic alkaloid from root bark, shows potential for treating depression and substance use disorder, but its cellular effects are unclear. In this study, ibogaine (100 µM) was applied to putative GABAergic neurons in the ventral tegmental area (VTA) from male and female mice. No effects were observed on membrane currents, membrane potential, or spontaneous excitatory postsynaptic currents in either sex. However, ibogaine increased intracellular calcium in both sexes, decreased action potential firing rate in males only, and altered afterhyperpolarization kinetics in females only. At baseline, male VTA neurons fired at higher frequencies than female ones. These sex-differentiated effects may contribute to ibogaine's therapeutic actions.
Dimethyltryptamine (DMT), a classic psychedelic with potential anti-depressive and anti-addictive properties, alters the electrical activity of certain neurons in the ventral tegmental area (VTA) of the mouse brain, with effects differing by sex. In an ex vivo study on I_h-negative neurons, a low concentration (500 nM) of DMT had no effect on electrophysiological properties in either sex. A high concentration (90 μM) increased action potential firing and changed membrane conductance at subthreshold potentials, but only in female neurons. DMT also raised cytosolic calcium levels in both sexes at the high concentration. The findings suggest that DMT activates mechanisms in females beyond the calcium changes seen in males, highlighting the importance of sex and dose in understanding its therapeutic potential.