Fig. 2. Acetylcholine induces higher current amplitude in neurons isolated from Anopheles gambiae strain AcerKis.

a Superimposed semilogarithmic dose-response curves for the ACh-induced currents recorded at a holding potential of −50 mV in isolated neurons from mosquito strains Kis (n = 5–15) and AcerKis (n = 3–14), as indicated in the graph. Data are mean ± S.E.M. b Comparative histogram illustrating the % acetylcholinesterase (AChE) activity determined spectrophotometrically in neurons isolated from Anopheles gambiae Kis (n = 18) and AcerKis (n = 6) strains. Bars represent mean ± S.D; Statistical test used was Student unpaired t-test, ***p < 0.001. Note the strong reduction in AChE activity measured in AcerKis neurons. c, d Histograms summarizing the effects of the carbamate insecticide, propoxur (100 µM), known to inhibit acetylcholinesterase, on both current amplitudes (c) and durations (d) evoked by ACh (1 mM, 3 s in duration). The current duration was measured at 50% of the amplitude. Bars represent mean ± S.E.M. (n = 6–16); Statistical test used was Student unpaired t-test, *p < 0.05; ns, non-significant. e The time to peak of the ACh-induced inward current recorded in AcerKis neurons was compared to that of measured in Kis neurons. Bars represent mean ± S.E.M. (n = 5–10); Statistical test used was Student unpaired t-test, *p < 0.05. f Comparison of cell body diameters between neurons isolated from Kis (n = 56) and AcerKis (n = 57) strains. Bars represent mean ± S.E.M. Statistical test used was the Mann–Whitney test, ns, non-significant. g, h Comparative histograms illustrating the charge density (g), calculated from the integral of the current according to the Eq. (3) and the current density (h) measured from the ACh-evoked inward current recorded in Kis and AcerKis neurons. Bars represent mean ± S.E.M (n = 4–5), Statistical test used was the Mann–Whitney test ^#p < 0.02. In all cases, the number of experiments (n) are biologically independent samples.