Figure 1.

Endogenous NR1 is expressed in axons and growth cones of glutamatergic hippocampal neurons. A–C, DIV3–DIV6 primary hippocampal cultures were coimmunostained for NR1 and the axonal protein tau. NR1 displays a punctate distribution throughout the cell and is present at axonal growth cones. C, DIV4 neurons were tripled labeled with NR1, tau, and the vesicular glutamate transporter VGLUT1. Positive immunostaining of VGLUT1 was present in all neurons that displayed NR1 at axonal growth cones, indicating that these neurons are glutamatergic. Scale bars: large panels, 50 μm; insets, 10 μm.