Figure 6.

Nerve terminals of MB neurons are more vulnerable to PI(4,5)P₂ accumulation. (A) Illustration for the role of synj1 in regulating phosphoinositide metabolism and the role of LY249002 (LY) in inhibiting the conversion of PI(4,5)P₂ to PI(3,4,5)P₃. (B) Representative pHluorin traces for cultured wildtype MB and cortical neurons at 10 Hz, 10 s stimulation before (black) and after LY (50 μM) incubation (red). (C) Summary of endocytosis kinetics and exocytosis fraction (the amplitude of the pHluorin trace at 10 Hz, 10 s stimulation normalized to the pHluorin response of that neuron to pH 7.4 NH₄Cl solution perfusion) before and after LY treatment in wildtype neurons. Green symbols and lines represent DAergic neurons by post-hoc analysis. (D) PHluorin traces from a Synj1^+/+ MB neuron (black) and a Synj1^+/− MB neuron (red) before drug treatment and at various times after LY incubation. (E) Summary of endocytosis and exocytosis kinetics before and during LY treatment in Synj1^+/− MB neuron neurons. Green symbols and lines represent DAergic neurons by post-hoc analysis. P-values in C and E are calculated by paired Student’s t tests.