Format

Send to

Choose Destination
Exp Brain Res. 1984;55(2):391-4.

Intrinsic membrane properties causing a bistable behaviour of alpha-motoneurones.

Abstract

In decerebrate cats a train of impulses in Ia afferents may lead to a sustained increase in excitability of alpha-motoneurones of homonymous and heteronymous muscles. It was previously suggested that this long-lasting excitability increase reflects a maintained synaptic input to the motoneurones from excitatory interneurones. With intracellular recording from motoneurones we here demonstrate that the sustained increase of alpha-motoneurone activity is due to an all-or-none plateau depolarization. This plateau can be induced by a short train of excitatory synaptic potentials or a brief, intracellularly injected depolarizing current pulse and is terminated by a short train of inhibitory synaptic potentials or a hyperpolarizing current pulse. It is concluded that maintained motor unit firing triggered by a brief train of impulses in Ia afferent reflects an intrinsic bistable behaviour of alpha-motoneurones.

PMID:
6086378
DOI:
10.1007/bf00237290
[Indexed for MEDLINE]

Supplemental Content

Loading ...
Support Center