Characterization of dopamine receptors in various species of invertebrates and vertebrates

Dopamine receptors can be characterized using ³H]spiroperidol binding in the brain of various animal species of vertebrates but are not detectable in nervous tissues of invertebrates. Among the mammals, considering the whole brain, the amount of dopamine receptor per unit of tissue decreases with increasing evolution. On the contrary, striatal dopamine receptor density is almost the same in the different mammalian brains examined. Dopamine receptor density in limbic areas increases from mice to monkeys.It is suggested that the enhancement of dopamine receptor density per unit of tissue in limbic areas parallels the degree of animal evolution.