EFFECTS OF THE PYRETHROID INSECTICIDE, DELTAMETHRIN, ON RESPIRATORY MODULATED HYPOGLOSSAL MOTONEURONS IN A BRAIN-STEM SLICE FROM NEWBORN MICE

We have studied the action of deltamethrin on respiratory modulated hy poglossal motoneurons in a brain stem slice from newborn mice. Deltame thrin depolarized the hypoglossal motoneurons, increased the backgroun d synaptic noise and reduced the frequency and amplitude of current el icited action potentials. Deltamethrin transiently increased the frequ ency of the respiratory rhythm. Inspiratory potentials in hypoglossal motoneurons were decreased in amplitude and increased in duration. In conclusion, deltamethrin perturbs the respiratory output from the hypo glossal nucleus through postsynaptic actions on bypoglossal motoneuron s and by affecting the inspiratory synaptic drive.