Unmasking of a neonatal somatovesical reflex in adult cats by the serotonin autoreceptor agonist 5-methoxy-N,N-dimethyltryptamine.
Brain research. Developmental brain research June 1, 1990 K B Thor, T Hisamitsu, W C De Groat 87 citations
In newborn kittens, urination is triggered by the mother licking the genital area, activating a spinal reflex. This reflex disappears around weaning and is replaced by a brain-controlled reflex that responds to bladder fullness. In adult cats, genital stimulation actually inhibits urination. The experiments tested whether temporarily suppressing the serotonergic system could restore the infant reflex in adult cats with intact spinal cords. Low doses of a serotonin agonist (5-MeODMT, 20-50 micrograms/kg) blocked the inhibition of bladder activity caused by genital touch or nerve stimulation in 9 of 10 adult cats. In 8 of those cats, the inhibition reversed to bladder contractions of varying strength, revealing the infant reflex. Higher doses (100-1000 micrograms/kg) stopped spontaneous bladder activity but did not prevent genital-triggered contractions.