Locus coeruleus neurons have axons that branch to the forebrain and cerebellum.

Utilizing a recently introduced double retrograde axonal tracing technique, the existence of collateralized axonal projections of locus coeruleus neurons to both forebrain and cerebellar cortical structures has been examined in adult mice. Following paired injection strategies using horseradish peroxidase and radiolabeled wheat germ agglutinin within portions of the forebrain and cerebellar cortices, substantial numbers of double labeled 'branched' neurons have been found that reside within all regions of the nucleus.