Svend S. Geertsen, Katinka Stecina, Claire F. Meehan, Jens B. Nielsen and Hans Hultborn Reciprocal Ia inhibition contributes to motoneuronal hyperpolarisation during the inactive phase of locomotion and scratching in the cat The Journal of Physiology 589
During a movement, the contraction of a given muscle group is often coordinated with the simultaneous relaxation of its antagonist muscles. The neural basis of this antagonist relaxation has been investigated in both animal and human experiments for decades and it is believed that activation of the Ia inhibitory interneurones by central motor programmes plays a major role in this relaxation of antagonist muscles. The alternating movements during locomotion would seem to especially require reciprocal actions, but recent studies have raised significant questions about the role of this inhibition. We found that inhibition evoked by these inhibitory interneurones is largest when their target motoneurones are inactive – even in the absence of supraspinal influence. The results of this work provide new evidence for the role of the Ia inhibitory interneurones during rhythmic motor activity. This supports the classical view of reciprocal inhibition as a basis for antagonist relaxation.
Complete the form below and we will send an e-mail message containing a link to the selected article on your behalf