Fig. 6.

5HT-Hi repulsion is regulated by cAMP signalling. Flamindo-2 accurately reports cAMP signaling in growth cones. a Representative images showing localization of cAMP. b Bath application of forskolin (n = 7, ± sem) to growth cones elicited a decrease in fluorescence indicating the activation of cAMP signaling. c Average change in cAMP in growth cones exposed to gradients of vehicle (open triangles, n = 8, ± sem), 5HT-Lo (open circles, n = 8, ± sem) and 5HT-Hi (open squares, n = 13, ± sem). d Quantitation of average changes in cAMP levels within growth cones after 15 min of serotonin exposure. 5HT-Hi significantly decreased (n = 12, p = 0.0003) cAMP levels and 5HT-Lo significantly increased (n = 8, p = 0.0076) cAMP signalling. (One-way ANOVA followed by Tukey’s multiple comparison post hoc test)