Zuranolone mimics which natural model?

• A. Progesterone
• B. GABA
• C. Pregnenolone
• D. Allopregnanolone

Answer: (D)

Zuranolone is a synthetic neuroactive steroid that reproduces the action of a natural brain molecule on the GABA-A receptor. The natural model it mimics is allopregnanolone, a potent endogenous neurosteroid produced in the brain from progesterone. Allopregnanolone binds to a neurosteroid site on the GABA-A receptor and enhances chloride influx, boosting inhibitory signaling. Zuranolone is designed as an analog of this endogenous molecule, so it reproduces allopregnanolone’s modulation of GABA-A receptors. Progesterone and pregnenolone are precursors in its biosynthesis and do not exert the same potent GABA-A modulation as allopregnanolone, while GABA is the receptor itself, not the endogenous modulatory molecule.