Figure 6.

Neuronal AP-3 complex is preferentially targeted to neuronal processes. Control, Ap3b1^-/-, Ap3b2^-/-, and mocha 7 and 15 DIV neurons were costained with delta and MAP-2 antibodies. (A) Depicts representative images of neuronal processes from 15 DIV neurons, note the reduced AP-3 levels in Ap3b2^-/- processes and the absence of signal in the mocha projections. (B) AP-3 fluorescence intensity analysis in neuronal cell bodies and processes. Fluorescence intensity from mocha cell bodies and processes was subtracted from control, Ap3b1^-/-, and Ap3b2^-/- values. There are no statistically significant differences in the cell body AP-3 content among different mouse genotypes. In contrast, processes of Ap3b2^-/- contain reduced levels of AP-3 both at 7 and 15 DIV. Asterisk and double asterisk denote p < 0.001 for control/Ap3b2^-/- and Ap3b1^-/-/Ap3b2^-/- respectively. The n values are described in Materials and Methods and as numbers at the bottom of the bars. AU = Arbitrary units.