REM atonia is primarily generated by which brain region?

REM atonia is primarily generated by which brain region?

• A. Medulla
• B. Cerebellum
• C. Pons
• D. Hippocampus

Answer: (C)

REM atonia is driven by brainstem circuits centered in the pons. During REM sleep, pontine neurons activate downstream pathways that inhibit spinal motor neurons, producing the deep muscle tone loss that prevents us from acting out dreams. The medulla helps implement the suppression of motor output, but the initiating and primary source of this atonia lies in the pontine region. Regions like the cerebellum or hippocampus aren’t responsible for generating this atonia; the cerebellum modulates movement more broadly, and the hippocampus handles memory rather than motor suppression during REM.

REM atonia is driven by brainstem circuits centered in the pons. During REM sleep, pontine neurons activate downstream pathways that inhibit spinal motor neurons, producing the deep muscle tone loss that prevents us from acting out dreams. The medulla helps implement the suppression of motor output, but the initiating and primary source of this atonia lies in the pontine region. Regions like the cerebellum or hippocampus aren’t responsible for generating this atonia; the cerebellum modulates movement more broadly, and the hippocampus handles memory rather than motor suppression during REM.