Figure 2.

Effects of HIV-1 Tat ± opioids on proliferation and the relative number of Olig2⁺ cells in vitro. Interactive effects of morphine and Tat reduced Olig2⁺ cell proliferation at both 24 and 48 h (A, B); Tat by itself also reduced Olig2⁺ proliferation at 48 h (B), and reduced the percent of Olig2⁺ cells in the overall population after both 24 h (C) and 48 h (D); there were no additional effects of morphine co-exposure. Morphine by itself did not affect Olig2⁺ proliferation or populations. Naloxone partially reversed the effect of morphine in both A and B; the percentage of Olig2⁺/BrdU⁺ cells in the Morph+Tat+Nal groups was not different from either control or Morph+Tat treatment groups at the same exposure time. Naloxone did not reverse the interactions between morphine and Tat in C and D (indicated as “a”), suggesting that naloxone might directly affect the Olig2⁺ population. This was not the case at 12 – 48 h exposure (E). Morph, Morphine (500 nM); Tat, HIV-1 Tat_1-86 (100 nM); Nal, naloxone (1.5 μM); * p < 0.05, ** p < 0.01, *** p < 0.001, ^a p < 0.05 vs. control; ANOVA with Duncan’s post-hoc test, n = 4–6.