The identification of motor and unpaired median neurones innervating the locust oviduct

The different classes of neurones supplying the locust oviduct were individually identified by intracellular recording and staining. We could thus show that different regions of the oviduct are innervated by different sets of neurones. Three motor neurones (oviductal neurones 1-3, OVN1-3) supply the oviduct via nerve N2B of the seventh abdominal ganglion. Whereas all three motor neurones innervate the junctional area of the lateral and the common oviduct (OVN1,2 and 3), the lateral oviduct is innervated by only one motor neurone (OVN2) and the common oviduct by two motor neurones (OVN1 and 2). The cell bodies of all three motor neurones lie ventrally, near the origin of the sternal root, and their neuropilar branches are confined to the seventh abdominal ganglion. The neuropilar branches of OVN1 and 2 extend mainly in the ipsilateral half of the ganglion; those of OVN3 reside exclusively in the contralateral half. The oviductal motor neurones, produce a phasic motor pattern, the oviductal rhythm, which causes neurogenic contractions of the junctional area and the common oviduct. These contractions serve to retain eggs in the lateral oviduct