Rat were exposed to 80% nitrous oxide in oxygen for 1 and 18 h. Met-enkephalin levels in the dorsal raphé, medial thalamus, periaqueductal grey, raphé magnus and locus coeruleus were measured by radioimmunoassay in control and treated animals. There was no change in Met-enkephalin levels at either time point in any of the brain areas examined. © 1984.
Morris, B., & Livingston, A. (1984). Effects of nitrous oxide exposure on Met-enkephalin levels in discrete areas of rat brain. Neuroscience Letters, 45(1), 11–14. https://doi.org/10.1016/0304-3940(84)90321-5