Fig. 4.

Developmental dynamics of sensitivity to CB2 receptor antagonist, AM-630 and AEA. Substances were given at the 2– 4 cell stage (B–E) or at mid-blastula 2 (G–I). Controls (A, F). AM-630 blocked cleavage divisions as shown by embryos composed of multiple blastomeres in B. AEA acted as a rescue substance to unblock cleavage divisions, as shown in C. However, when given at mid-blastula 2, AM-630 partially rescued from the effects of AEA (H). A–E Imaged at mid-blastula 2; F–H imaged at late gastrula. Scale bar = 50 μm.