In contrast, morphine-induced analgesia in initially active females who were housed in standard cages for 17 days prior to a second nociceptive test was enhanced relative to their first nociceptive test and to presently active rats. These observations showed that the attenuation of morphine analgesia induced by running is reversible and not permanent. These results indicate that chronic activity can decrease morphine's analgesic properties. These effects may be due to cross tolerance between endogenous opioid peptides released during exercise and exogenous opioids. Kararek, R.B., Gerstein, A.V., Wildman, R.P., Mathes, W.F., D'Anci, K.E. Pharm.
Homer modulates the activity and assembly of the metabotropic receptor.
Group 1 metabotropic glutamate receptors activate phosphatidylinositol turnover and trigger intracellular calcium release. These studies identify a novel mechanism in calcium signaling and provide evidence that an immediate early gene, whose expression is driven by synaptic activity, can directly modify a specific synaptic function. P.F. Neuron 21, pp. Subunit and Subtypes of Receptors in Embryonic Sympathetic Neurons Previous work has shown the presence of the a7 subunit of the nicotinic acetylcholine receptor to be present in the brain. Yu and Role recorded from sympathetic neurons in order to determine the physiological role of a7 nicotinic receptors in the brain.