Ventilation and Neurochemical Changes During µ-Opioid Receptor Activation or Blockade of Excitatory Receptors in the Hypoglossal Motor Nucleus of Goats

Activation of inhibitory µ-opioid receptors in the hypoglossal motor nucleus decreased ventilation under physiological conditions and did not affect neurochemicals in effluent dialyzed mock cerebrospinal fluid. These findings contrast with studies in the ventral respiratory column where unilateral [d-Ala2, N-MePhe4, Gly-ol]enkephalin (DAMGO) had no effects on ventilation and bilateral DAMGO or unilateral atropine increased ventilation and decreased GABA or increased serotonin, respectively. Our data support the hypothesis that mechanisms that govern local compensatory neuromodulation within the brain stem are site specific under physiological conditions.