Fig. 3.

METH administration causes the shuttling of (A) NFATc3 and (B) NFATc4 proteins from the cytosol to the nucleus and increases in the expression of calcineurin (C-F) in the rat striatum: effects of treatment with SCH23390, a DA D1 receptor antagonist. Nuclear and cytosolic fractions were separated as described in the text. The fractions were obtained from individual striatal samples of six animals per time point. Representative photomicrographs show results of three samples per time point. METH caused time-dependent decreases in the cytosolic fraction and parallel increases in the nuclear contents of NFATc3 and NFATc4. Pretreatment with SCH23390 before METH injection completely blocked METH-induced increases in the nuclear fractions. Time-dependent increases were observed by using antibodies against (C) calcineurin Aα, (D) calcineurin Aβ, (E) pan-calcineurin A (which recognizes calcineurin Aα and calcineurin Aβ), and (F) calcineurin Bβ2, the regulatory subunit of calcineurin. These increases were significantly attenuated by pretreatment with SCH23390. The membranes were reprobed with α-tubulin antibody to confirm equal protein loading. The values represent means ± SEM (n = 6) (fold changes with respect to control). Open column, saline-pretreated METH-challenged rats (prior treatment of saline followed by saline or METH); closed column, SCH23390-pretreated METH-challenged rats (prior treatment of SCH23390 followed by saline or METH). ^*, P < 0.05; ^**, P < 0.01; ^***, P < 0.001, increases in comparison with the respective control group;!, P < 0.05, decreases in comparison with the respective control group.