Sections selected for TH and D1R dual-label immunoEM were rinsed several times in 0.1M PB then incubated in a 1% solution of sodium borohydride for 30 minutes at RT. After rinsing, sections were blocked in 10% NGS (Invitrogen, Inc.) containing 0.03% Tx for 1 hour at RT, then incubated for 36 hours at RT in a solution containing mouse anti-TH (1:1000, Millipore). Following extensive rinsing, sections were incubated in a 10% solution of NGS containing biotinylated goat anti-mouse IgG (1:200, Vector Labs) for 2 hours at RT and, again after rinsing, were incubated with ABC (Vector Labs) for 1 hour at RT. The sections were reacted with 0.05% DAB containing 0.01% H2O2 for 3 minutes. After rinsing, sections were incubated for 36 hours at RT in a solution containing rat anti-D1R (1:500, Millipore). Following extensive rinsing, sections were incubated in a 10% solution of NGS containing biotinylated goat anti-rat IgG (1:200, Vector Labs) for 2 hours at RT and, again after rinsing, were incubated with ABC for 1 hour at RT. The sections were reacted with Vector Slate Grey (SG) (Vector Labs) for 3 minutes. Sections selected for TH and D2R dual-label IHC () were rinsed several times in 0.1M PB then incubated in a 1% solution of sodium borohydride for 30 minutes at RT. After rinsing, sections were blocked in 10% NGS (Invitrogen, Inc.) containing 0.03% Tx for 1 hour at RT, then incubated for 36 hours at RT in a solution containing mouse anti-TH (1:1000, Millipore). Following extensive rinsing, sections were incubated in a 10% solution of NGS containing biotinylated goat anti-mouse IgG (1:200, Vector Labs) for 2 hours at RT and, again after rinsing, were incubated with ABC for 1 hour at RT. The sections were reacted with 0.05% DAB containing 0.01% H2O2 for 3 minutes. After rinsing, sections were incubated for 36 hours at RT in a solution containing rabbit anti-D2R (1:500, Millipore). Following extensive rinsing, sections were incubated in a 10% solution of NGS containing biotinylated goat anti-rabbit IgG (1:200, Vector Labs) for 2 hours at RT and, again after rinsing, were incubated with ABC for 1 hour at RT. The sections were reacted with SG for 3 minutes. After the completion of the IHC reactions, the sections were fixed in a solution of 1% osmium tetroxide (Electron Microscopy Sciences) and 1.5% potassium ferricyanide (Sigma-Aldrich Corp) in 0.1M PB for 30 min at RT in the dark. The sections were dehydrated, stained with 1% uranyl acetate en bloc, and flat embedded in Durcupan epoxy resin (components A–D, Sigma-Aldrich Corp.) between two sheets of aclar fluorohalocarbon film. The epoxy resin was allowed to polymerize at 70°C for 72 hours. An area of known size (0.5 × 0.5 mm) was selected from the striatum. Ultrathin serial sections (silver, ~60–70 nm) were cut (~10 per grid), mounted on formvar-coated copper slot grids, and stained with uranyl acetate and lead citrate prior to viewing. The electron microscopic images were captured on a JEOL 100 CXII electron microscope equipped with a side mounted MegaView digital camera coupled to analySIS® image analysis software., We describe a series of reliable, modified ‘Golgi-Cox’ impregnation methods that complement some existing methods and have several advantages over traditional whole brain ‘Golgi’ impregnation., In the present study, we described a protocol of Golgi-Cox Staining for Cryosection, with the modified cryosection protection solution based on the Golgi-Cox method, which makes cryosection easy to apply in the section of the Golgi-Cox impregnated tissue..