Projections from the interstitial nucleus of cajal to the inferior olive and to the spinal cord in cat: A retrograde fluorescent double-labeling study

Abstract

Injections of the fluorescent dyes Fast Blue (FB) and Nuclear Yellow (NY) were placed in the inferior olive and cervical spinal cord respectively in three experimental animals. Results showed that the interstitial nucleus of Cajal (INC) projected mainly to the spinal cord, with only a modest termination within the inferior olive. The nucleus of Darkschewitsch and the rostromedial portion of the red nucleus projected heavily to the inferior olive but not to the spinal cord. Very few INC neurons were double-labeled with FB and NY, suggesting that only a small minority of spinal projecting neurons in the INC give rise to collaterals which terminate within the inferior olive.