Cholesterol reduction is a necessary trigger for the CYP46A1-dependent increase in dendritic protrusion density and p-Trk levels. ( A,B ) Primary cultures of rat cortical neurons 19 DIV were transduced with AdControl or AdCYP adenovirus and maintained for 48 hours. 24 hours after transduction cells were incubated with 10 μM Chol:MBCD. Neurons were stained with filipin III (blue) and immunstained with p-Trk (red). Statistical analysis was performed by two-way ANOVA followed by Tukey post-hoc test (* p