Fig. 2.

Subcellular localization of PDE4D, HCN1, and mGluR3 in ERC layer II dendritic spines. Immunoperoxidase labeling revealed that PDE4D, HCN1, and mGluR3 were focused in dendritic spines near asymmetric, glutamate-like synapses in rhesus macaque ERC layer II. (A) PDE4D was observed directly in association with the SER spine apparatus (pseudocolored pink). (B) HCN1 and (C) mGluR3 were localized on the dendritic spine plasma membrane adjacent to the SER spine apparatus. Synapses are between black arrows. Color-coded arrowheads point to PDE4D (green), HCN1 (red), and mGluR3 (yellow) immunoreactivity. Profiles are pseudocolored for clarity. Ax, axon; Sp, dendritic spine; Mit, mitochondria. Scale bars, 200 nm.