Serotonergic lesions decrease mu- and delta-opiate receptor binding in discrete areas of the hypothalamus and in the midbrain central gray.
Allen DL, Johnson AE, Tempel A, Zukin RS, Luine VN, McEwen BS. Serotonergic lesions decrease mu- and delta-opiate receptor binding in discrete areas of the hypothalamus and in the midbrain central gray. Brain Res. 1993 Oct 22; 625(2):269-75.