In-Vivo Electrophysiology

Pilot rodent mPFC recordings show two neurons responding significantly differently to psilocybin administration

Pilot electrophysiological recordings in the medial prefrontal cortex (mPFC) of rodents revealed that two distinct neuron types exhibited significantly different responses to psilocybin administration.

Specifically, putative GABAergic (inhibitory) neurons demonstrated an increase in firing frequency following psilocybin exposure, while putative glutamatergic (excitatory) neurons showed a marked decrease in firing activity. These opposing changes suggest that psilocybin may shift the excitation-to-inhibition balance within the mPFC toward a more inhibitory state, potentially underlying its observed antidepressant effects.

Firing Rate Vs. Time For Individual Neuron Activity in GABA and Glutamate Neurotransmitters

GABAergic Response

GABAergic-like signals increased mPFC firing frequency

Glutametergic Response

Glutamatergic-like signals reduced mPFC firing frequency

Electrodes implanted in the prelimbic mPFC recorded baseline activity for 20 min before psilocybin injection (1 mg/kg IP), followed by 1 hr of post-injection recording. Data was processed in Plexon's OmniPlex and Offline Sorter V-4.
Single-unit activity was analyzed, and a paired t-test compared neuronal firing rates before and after psilocybin.