Chemical Communication 
assay for monitoring the activity of G protein- 
coupled receptors that act to raise or lower intra- 
cellular cAMP or that raise intracellular IP3/DAG. 
The ability of exogenous receptors to couple to 
and control the pigment translocation appa- 
ratus within melanophores should lead to im- 
proved methods for studying G protein-coupled 
receptors. 
258 
