Ultrastructural Localization of Dopaminergic Receptors in the Amygdala of Rat

The present study was performed to identify the dopaminergic receptor sites in rat amygdala. Identification of the receptor sites at ultrastructrual level has been done by autoradiography after cerebral ventricular perfusion of ³H-haloperidol.

From 434 examples of silver grains, 5% were labeled in soma, 36% in thick dendrites, 26% in the thin branches of axons and dendrites, 21% in thick axons and terminals and 12% in synapses with synaptic vesicles. In the cases of labeled synapses, all of axon terminals contained small round vesicles and showed asymmetric contact with dendrites. By these results it may be implied that dopamine receptors in the amygdala are located in both pre-and post-synaptic sites of the asymmetric axo-dendritic synapses with small round vesicles and the axons of labeled synapses originated from the dopaminergic neurons in the midbrain.