Figure 1.

Effect of haloperidol on ribosomal protein S6 (rpS6) phosphorylation in striatal medium spiny neurons (MSNs). (a) Western blot analysis of phospho-Ser235/236-rpS6 (P-235/236-rpS6) in the striata of mice treated with vehicle (Veh) or haloperidol (Hal; 0.5 mg/kg) and killed after 15 or 60 min. Right panels show representative autoradiograms obtained using antibodies against P-235/236-rpS6 (upper) and total rpS6 (lower). Left panel is a summary of data represented as means±SEM (n=5–7; ^*p<0.05 vs Veh). (b) Confocal sections of the dorsal striata, showing immunofluorescence for P-Ser235/236-rpS6 in mice treated with Veh or Hal and perfused 15 or 60 min later. Scale bar=40 μm. (c and d) Mice expressing enhanced green fluorescent protein (EGFP) in striatopallidal (Drd2-EGFP) or striatonigral (Drd1a-EGFP) MSNs were treated with Veh or Hal (0.5 mg/kg) and perfused 15 or 60 min later. (c) Quantification of P-235/236-rpS6 immunoreactive neurons among EGFP-positive (D2-positive) or EGFP-negative (D2-negative) neurons in the dorsal striata of Veh or Hal treated Drd2-EGFP mice (^**p<0.001 vs respective Veh). (d) Confocal sections of the dorsal striata of mice treated with Veh or Hal and perfused 15 min later, showing immunofluorescence for P-235/236-rpS6 in combination with EGFP fluorescence. Scale bar=30 μm. (e and f) Mice expressing EGFP in striatopallidal (Drd2-EGFP) MSNs were repeatedly treated with Veh or Hal (0.5 mg/kg, one daily injection during 2 weeks) and perfused 15 min after a challenge injection of Veh or Hal. (e) Quantification of P-235/236-rpS6 immunoreactive neurons among EGFP-positive (D2-positive) or EGFP-negative (D2-negative) neurons in the dorsal striata of Drd2-EGFP mice treated chronically (2 weeks) with Veh or Hal and challenged with Veh or Hal (^**p<0.001 vs Veh; °°p<0.01 vs Hal). (f) Confocal sections of the dorsal striatum, showing immunofluorescence for P-235/236-rpS6 in combination with EGFP fluorescence. Scale bar=30 μm.