- Functional interaction between TRPV1 and mu-opioid receptors in the descending antinociceptive pathway activates glutamate transmission and induces analgesia. Maione, S., Starowicz, K., Cristino, L., Guida, F., Palazzo, E., Luongo, L., Rossi, F., Marabese, I., de Novellis, V., Di Marzo, V. J. Neurophysiol. (2009)