Convergence in the Reciprocal la Inhibitory Pathway of Excitation from Descending Pathways and Inhibition from Motor Axon Collaterals
Version of Record online: 8 DEC 2008
© 1972 Scandinavian Physiological Society
Acta Physiologica Scandinavica
Volume 84, Issue 1, pages 95–108, January 1972
How to Cite
Hultborn, H. and Udo, M. (1972), Convergence in the Reciprocal la Inhibitory Pathway of Excitation from Descending Pathways and Inhibition from Motor Axon Collaterals. Acta Physiologica Scandinavica, 84: 95–108. doi: 10.1111/j.1748-1716.1972.tb05159.x
- Issue online: 8 DEC 2008
- Version of Record online: 8 DEC 2008
- Received 1 July 1971
With intracellular recording from motoneurones and utilizing the technique of spatial facilitation it has been investigated if those la inhibitory interneurones which receive excitation from supraspinal centres also can be inhibited from recurrent motor axon collaterals. For each motoneurone the stimulation strengths were chosen so that separate stimulation of either the supraspinal system or la afferents did not evoke any 1PSP while a combined stimulation at suitable intervals gave a large IPSP. When preceded by stimulation of ventral roots this test IPSP was abolished or decreased. This was found in about 100 motoneurones belonging to different hindlimb muscles in which an IPSP appeared after facilitation from vestibulo-, rubro-or cortico-spinal tracts.
It is thus concluded that a convergence of supraspinal excitation and recurrent inhibition occurs on the same la inhibitory interneurones.