The responses to nerve stimulation of the salivary gland of Nauphoeta cinerea Olivier.

A study has been made with intracellular electrodes of the responses of acini of the salivary gland of Nauphoeta cinerea Olivier to salivary duct nerve stimulation. The gland is a paired structure and offers the possibility of investigating the interaction between ipsi- and contralateral nerve stimulation. 2. The characteristics of the responses are as previously described for field stimulation (House, 1973). The latency is of the order of 1 sec and almost independent of the amplitude of the response which may attain a hyperpolarization of about 80 mV. The depolarization which sometimes follows can be disassociated from the preceding hyperpolarization and is presumably an independent response. 3. The stimulus-response relationship shows that acini are multiply innervated. Those close to the mid line recieve axons from both ipsi- and contralateral salivary duct nerves. The response to a test stimulus T can be augmented by an immediately preceding conditioning stimulus C, the joint response being greater than the sum of the separate responses. This effect occurs even when C and T are delivered to different nerves. For longer intervals between C and T, the response to T is depressed.