Do gi proteins regulate adenylyl cyclase activity independent of receptor activation?
Together, these data indicate that Gi exerts intrinsic receptor-independent inhibitory activity upon AC. We propose that PTX treatment shifts the balance of intrinsic G(i) and Gs activity upon AC towards Gs, enhancing the effect of all cAMP-mediated inotropic agents.
The M50 response, which shows habituation to repetitive stimulation, was not localized to the auditory cortex, but showed multiple sources including frontal lobes.