Abbreviations CaMKII calcium calmodulin kinase CNS central nervous system DAG diacylglycerol DAMGO [d-Ala 2 , N -MePhe 4 ,Gly-ol]enkephalin DOR -opioid receptor ERK1/2 extracellular signal-regulated kinases FRET fluorescence resonance energy transfer GIRK G protein-gated inwardly rectifying potassium channel G6976 12-(2-cyanoethyl)-6,7,12,13-tetrahydro-13-methyl-5-oxo-5 H -indolo(2,3- a )pyrrolo(3,4- c )carbazole GPCR G protein-coupled receptor GRK G protein receptor kinase ICI174864 N , N -diallyl-Try 1 .Aib 2,3 ,Leu 5 ]enkephalin JNK c-Jun N-terminal kinases Kir3 GIRK isoform KOR -opioid receptor MAPK mitogen-activated protein kinase ME [Met] 5 enkephalin MOR -opioid receptor NaPP1 4-amino-1- tert -butyl-3-(1-naphthyl)pyrazolo[3,4- d ]pyrimidine NMDA N -methyl-d-aspartate PKC protein kinase C PLD phospholipase D RAVE relative activation versus endocytosis RGS regulator of G protein signaling rMOR a transgenic MOR mouse in which part of the C-terminal region of the DOR is substituted into MOR ROS reactive oxygen species [ 35 S]GTP S 35 S-labeled guanosine-5- O -(3-thio)triphosphate SL327 [ -[amino[(4-aminophenyl)thio]methylene]-2-(trifluoromethyl)benzeneacetonitrile U0126 1,4-diamino-2,3-dicyano-1,4-bis(methylthio)butadiene Authorship Contibutions Wrote or contributed to the writing of the manuscript: Williams, Ingram, Henderson, Chavkin, von Zastrow, Schulz, Koch, Evans, Christie

Integration matters
He rejects the idea of living foreverStatistically, youre going to have an accident, and, if you dont have an accident, then someday the star system will endthough he does think that we are a matter of years away from achieving indefinite life spans