Brazilian Journal of Medical and Biological Research (2001) 34: 919-937 Activity of caudal raphe neurons 919 ISSN 0100-879X Behavioral correlates of the activity of serotonergic and non-serotonergic neurons in caudal raphe nuclei L.E. Ribeiro-do-Valle Departamento de Fisiologia e Biofísica, Instituto de Ciências Biomédicas, and R.L.B.G. Lucena Universidade de São Paulo, São Paulo, SP, Brasil Abstract Correspondence We investigated the behavioral correlates of the activity of serotoner- Key words L.E. Ribeiro-do-Valle gic and non-serotonergic neurons in the nucleus raphe pallidus (NRP) · Nucleus raphe pallidus · Departamento de Fisiologia e and nucleus raphe obscurus (NRO) of unanesthetized and unre- Nucleus raphe obscurus Biofísica, ICB, USP · strained cats. The animals were implanted with electrodes for record- Waking-sleep cycle 05508-900 São Paulo, SP · Respiration ing single unit activity, parietal oscillographic activity, and splenius, Brasil · Startle behavior E-mail:
[email protected] digastric and masseter electromyographic activities. They were tested · Drinking behavior along the waking-sleep cycle, during sensory stimulation and during Research supported by FAPESP drinking behavior. The discharge of the serotonergic neurons de- and CNPq. creased progressively from quiet waking to slow wave sleep and to fast wave sleep. Ten different patterns of relative discharge across the three states were observed for the non-serotonergic neurons. Several Received August 8, 2000 non-serotonergic neurons showed cyclic discharge fluctuations re- Accepted April 17, 2001 lated to respiration during one, two or all three states. While serotoner- gic neurons were usually unresponsive to the sensory stimuli used, many non-serotonergic neurons responded to these stimuli.