Figure 7.

NSPA is expressed by neurons at specific regions of the brain. (A) Immunohistochemistry of NSPA in the rat brain. Some brain regions with framed zones of higher magnification (insets) are illustrated. Arrows indicate interneurons, synaptic buttons, and calyx-like terminals. Bars: (cortex, left) 100 μm; (cortex, right) 10 μm; (hippocampus, left) 50 μm; (hippocampus, right) 10 μm. The bed nucleus of stria terminalis and the central nucleus of the amygdala are also shown. Bars, 10 μm. (B) The immunogenic NSPA peptide completely abrogated the staining (not depicted). (C) Summary of NSPA expression in neurons of different areas of the brain, indicating whether the staining was detected in somatodendritic or axonal (synaptic buttons) regions. (D) Correspondence between immunohistochemical staining and immunoblot detection of NSPA. Synaptosomes were isolated from the cortex (lane 1), which shows positive immunohistochemical staining, and from the striatum (lane 2), which completely lacks staining. Immunoblot with α-NSPA and α-hP₁₁ show p331 only in synaptosomes from the cortex. In contrast, the dopamine transporter (DAT), which is 90% expressed in the striatum (reference 73), was exclusively detected in this region, thus showing that these two brain areas were effectively isolated.