indeed.
peripheral sources are epithelial cells in the torso, usual suspects... lungs, heart, adrenals, muscles..
great find!
sigma-1 receptors are 7-transmembrane (metabotropic), with a signal amplification process that is analogous to the photoelectric effect. fascinating stuff, cellular signaling is.
love the avatar btw
"Nothing is true, everything is permitted." ~ hassan i sabbah
"Experiments are the only means of attaining knowledge at our disposal. The rest is poetry, imagination." -Max Planck