Journal of Neurophysiology, Vol 38, Issue 3 531-538, Copyright © 1975 by APS
Medial recticular neurons projecting Rostrally
J. C. Eccles, R. A. Nicoll, H. Taborikova and T. J. Willey
1. In the latter part of investigations on the medial reticular neurons,
stimulation was applied to the ipsilateral tegmental tract in the upper
pontine level. Of the 426 neurons in this series, 56 had rostrally
projecting axons as evidenced by their antidromic responses. 2. Of these 56
neurons, 41 were activated by limb nerve stimulation, usually very
strongly, and so qualify as units in the reticular activating system.
Fastigial stimulation monosynaptically excited 14 of these reticular
activating neurons, so providing and ascending pathway from the cerebellar
vermis. 3. Axonal branching has been demonstrated by antidromic testing in
four reticular neurons with ascending axons. In two there were branches to
the fastigial nucleus and in two, down the spinal cord. 4. The latency
histograms of the excitatory and inhibitory responses resembled those for
reticular neurons with descending axons except for the poverty of
inhibitory responses in neurons not receiving a fastigial projection.
