Research Paper Volume 14, Issue 13 pp 5345—5365

Figure 4. (A–D) Anxiety-like behavior in the open field and elevated plus-maze and (A’–D’) simple linear regressions between circulating and central steroid hormones among young adult and middle-aged HIV-1 Tat-transgenic male mice [Tat(+)] or their non-Tat-expressing age-matched counterparts [Tat(−)]. (A) Time (s) spent in the brightly-lit center of an open field. (B) Numbers of entries made into the center of an open field. (C) Latency (s) to enter the open arms of an elevated plus-maze. (D) The proportional time spent in the open arms of an elevated plus-maze. Regressions between (A’) circulating corticosterone and center time, (B’) hippocampal allopregnanolone and center entries, (C’) circulating corticosterone and latency to enter open arms, and (D’) circulating T and proportional open arm time. ^*main effect for Tat genotype wherein Tat(+) mice to differ from Tat(−) mice. ^†main effect for middle-aged mice to differ from young adult mice. ^{^}significant interaction wherein indicated group differs from young adult Tat(−) controls. Regression lines (solid) are depicted with 95% confidence intervals (dotted), (two-way ANOVA, p < 0.05).