dosR in the posterior regions of the Thalassoma pavo treated with a MAT concentration of Cd (a; n = 4) and of H3 Binding pattern of these two subtypes appeared to be highly specific as shown by very similar background levels reported for [ 3 H]-NAMH in presence of a 500? concentration of the selective antagonists cimetidine (c) and thioperamide (d), respectively, as described in “Materials and Methods.”