Release of transmitters on stimulation of the nucleus linearis raphe in the cat.

The nucleus linearis intermedius raphe and the nucleus linearis rostralis were stimulated during the perfusion of the anterior horn of the right lateral ventricle of anaesthetized cats. Whereas release of 5-hydroxytryptamine (5-HT) was consistently obtained, there was no release of acetylcholine (ACh). The independence of the release of 5-HT from that of ACh was seen both during low basal release of ACh (rising base line), and during the period when a plateau of resting release had been reached. It was also demonstrated in experiments in which the same perfusate was examined for both compounds.