Fig. 4.

Meth induces the opening of hemichannels in mixed cultures of human neurons and astrocytes. (a) The rate of ethidium (Et) uptake by glial cells incubated in the absence or presence meth was measured up to 48 h. An increase in channel opening was evident in the first 5–15 min after meth (10 μM, lines with circles) treatment, followed by a smaller but significant opening between 6 and 48 h (lines with circles). No channel opening was observed in untreated cultures (control, lines with squares). (b) Connexin hemichannels blockers, but not pannexin-1 hemichannel blockers (data not shown), reduces the opening of the hemichannel induced by meth treatment. Lanthanum, 100 μM, La⁺³; Cx36 mimetic peptide, 500 μM; and Cx43 mimetic peptide, 500 μM) prevented Et uptake induced by meth. The time point analyzed correspond to 10 min after treatment. [*p < 0.05 as compare to control conditions (con, c), #p < 0.05 as compared to meth-treated conditions, n = 4].