Transient cessation of female rat sexual cycle after electrolytic damage of locus coeruleus.

In order to evaluate the possible participation of the locus coeruleus (LC) in the regulation of estrous cyclicity, bilateral LC electrolytic lesions were made in intact female rats. Vaginal smears were sampled daily and the estrous cyclicity was established. LC lesions resulted in a transient loss of cyclicity characterized by a sustained diestrous period. The delay in recovery was dependent on the percentage of LC destroyed. The cyclicity of sham operated rats and of nonoperated rats showed no change. Results are discussed within the context of the LC as a generalized influencing system.