Fig. 2. Ultrastructural and subsynaptic localization of D1Rs in the PFC.
(A) Mean ± SEM percent of total D1R-labeled neuronal elements in the PFC as revealed with the pre-embedding immunogold method. *p<0.05, **p<0.01 compared to dendrites. (B) Mean ± SEM percent total D1R immunogold particle labeling associated with the plasma membrane or the intracellular compartment in different PFC neuronal elements. #p<0.05, ##p<0.01 compared to intracellular compartment for that element. (C) Mean ± SEM percent of D1Rs localization on dendrites and spines when associated with the plasma membrane. +p<0.01, ++ p<0.001, +++p<0.0001 compared to extrasynaptic labeling for that element. (D) Representative electron micrograph of a D1R-labeled dendrite, unmyelinated axon and spine. Single arrows indicate intracellular gold particles, double arrows indicate plasma membrane bound extrasynaptic labeling, and arrowhead indicates synaptic labeling at an asymmetric synapse. N=3 rats. Total number of labeled elements examined: 132 dendrites, 42 spines, 120 unmyelinated axons, and 50 axon terminals. Total number of immunogold particles counted: 470 from dendrites, 83 from spines, 255 from unmyelinated axons, and 142 from axon terminals. Den, dendrite; Sp, dendritic spine; UA, unmyelinated axon; AT, axon terminal; Ul, unlabeled. Scale bar = 0.5 μm.