Membrane potential and input resistance of cat spinal motoneurons in wakefulness and sleep.
Level 5 - mechanism / opinion, no new human data
Animal neurophysiological study (bench/animal research)
PubMed 7248060 · doi:10.1016/0166-4328(81)90060-7
What was done
Input resistance and membrane potential were measured using double-barrelled micropipettes in hindlimb spinal motoneurons across wakefulness and sleep states in chronically implanted, restrained cats.
What was found
During postural atonia in rapid-eye-movement (REM) sleep, motoneurons exhibited sustained hyperpolarization of 5-8 mV and a 30% decrease in input resistance. Membrane potential and input resistance showed little difference between wakefulness and other sleep states.
Why it matters
These findings provide direct cellular evidence that motor deactivation during REM sleep atonia is driven by active postsynaptic inhibition rather than disfacilitation.
Limits
The experiment was conducted in an animal model (cats) under physical restraint. The abstract does not report the number of animals or neurons recorded, nor any measures of statistical variance.
Cited by
- supports During REM sleep, skeletal muscles are paralyzed because alpha motor neurons are hyperpolarized.