Figure 1.

Time-course of behavioral testing. In week 1, Tat protein expression was induced in young adult (6–8 mos. old) and middle-aged (11–13 mos. old) male mice via doxycycline administration (30 mg/kg, i.p. for 5 d) followed by two days of doxycycline washout. In week 2, mice were assessed for affective-like behavior in the open field (OF) and elevated plus-maze (EPM). In weeks 3 and 4, spatial memory performance was assessed in a radial arm water maze (RAWM). In week 5, neuromuscular function was assessed by grip strength and nociceptive/analgesic responding was assessed via the electronic-Von Frey and thermal probe tests.