A mechanism of signal transduction operating with opiate receptors

Abstract A concept of signal transduction in biological systems specifies that any instantaneous input is appreciated by its departure from the moving average of past activity. Numerical simulations that implemented this concept adequately fitted three samples of empirical data indicating sustained opiate receptor activation (1) to cause a downward shift in stimulating [ 35 S]-GTP γ S binding, (2) to produce time-dependent tolerance to analgesia, and (3) to induce time- and dose-dependent hyperalgesia. The proposed transduction mechanism thus appears to operate at cell membrane opiate receptors and to account for the characteristic expressions (i.e., tolerance, dependence) of neuroadaptive plasticity in opiate systems.