The excitability and rhythm of medullary respiratory neurons in the cat are altered by the serotonin receptor agonist 5-methoxy-N,N, dimethyltryptamine.
Brain research June 13, 1994 P M Lalley 37 citations
5-MeO-DMT, a compound that activates serotonin receptors, had two distinct effects on brainstem respiratory neurons in cats. Larger doses (43 ± 8.9 μg/kg) silenced these neurons by hyperpolarizing them, an effect reduced by a serotonin receptor blocker given intravenously but not locally. Smaller doses (27 ± 2.78 μg/kg) increased the firing rate of both inspiratory and expiratory neurons, making inspiratory bursts shorter and expiratory bursts start earlier relative to breathing rhythm. The larger-dose depression appears to involve both presynaptic network effects and postsynaptic activation of 5HT-1A receptors, while the smaller-dose excitation likely results from binding to 5HT-1A receptors on early inspiratory neurons.