Heroin

Pleasure: the normal condition 3

When an electric signal arrives at an endorphin neuron, the endorphin vesicles fuse to the wall of the neuron. This releases the endorphins into the space (synapse) between two neurons.

The endorphins now move across the synapse to a GABA neuron. The dendrites of that neuron contain receptors to which the endorphins can bind. This binding action relays the message further. This message leads to a reduction in the release of GABA.

The endorphins unbind from the receptor and are broken down immediately.