Effect of morphine on a depolarising dopamine response.

THE structural complexity of nervous tissues and the presence of non-neuronal elements have hindered investigations into the actions of morphine at the cellular level in the vertebrate central nervous system, and contribute to the difficulty of determining whether morphine acts pre- or postsynaptically. Although presynaptic effects of morphine are documented, to our knowledge there has been no demonstration of an effect of morphine on postsynaptic neurotransmitter receptors using intracellular recording techniques.