Changes in conduction velocity within a nerve net

Conduction velocity within the through‐conducting nerve net of the sea anemone Calamactis praelongus is altered as a result of the passage of one or more impulses. Facilitation of conduction velocity occurs when the second evoked impulse follows the first by less than 2 sec. The facilitating effect increases with decreasing interval between shocks until impulses are less than 0.5 sec apart and then it declines. Antifacilitation occurs when the nerve net is shocked at frequencies between one per 2 sec and one per 20 sec. It is seen also after the first two or three responses when shocks are applied at higher frequencies. Facilitation and antifacilitation increase with spread of excitation. Although the relationship of velocity changes to the behavior of Calamactis has not yet been determined, facilitation of conduction velocity in the net may produce greater synchronization of muscle contraction.