The concept of neurosecretoon as it emerged from the discussions of the Naples Symposium has proved fruitful in many ways; it served once more as the basis of the agenda of the Lund Symposium. The neurosecretory cell may still be defined as a nerve cell which receives nervous impulses, but does not pass them on to other neurons or effector organs. The axon of the neurosecretory cell ends at the wall of a blood space into which it releases its product. It is, of course, conceivable that a neuron discharges visible secretory granules anywhere on its surface, while its axon maintains synaptic connections with other cells. However, no such case is known at present, and the definition of the neurosecretory cell as a nerve cell which secretes microscopically demonstrable granules via its axon into the blood is still valid.