Figure 5. Haloperidol treatment leads to increased spines in striatal neurons in vitro and cortical Layer 5 pyramidal neurons in vivo.

(A) Primary striatal cultures were co-plated with cortical neurons, grown to DIV14, and treated for 24 hours with either haloperidol or vehicle. Images were processed using ImageJ and spines were quantified on primary and secondary projections where detectable. Skeletal representative images are shown and are line enhanced for visualization. Spines that met specified criteria (see Materials and Methods) were quantified (n=4, p<0.0001). Primary indicates spines counted on primary projections from the soma; secondary indicates spines counted on secondary projections that branch from primary projections. The scale bar indicates 5 μm. S6K1 shRNA treated neurons (B) Experimental procedure for in vivo study. One-month-old Thy-1 YFP mice underwent surgery to place head-fixation bars prior to initial imaging session (Day 0), were imaged, and then either injected with haloperidol or vehicle and imaged again 24 hours later. (C) Processed representative images of cortical Thy-1 YFP positive neurons are shown for clarity. Asterisks indicate filopodia, closed arrowheads indicate spines that formed, and open arrowheads indicate spines that were eliminated. The number of spines eliminated or formed is plotted. (Veh=4, Hal=6, p = 0.006). All graphs shown are average ± SEM and analyzed by Student’s t-test for statistical differences. p ≤ 0.05 is indicated by the asterisk.