The passive electrical characteristics of giant neurones identified in the central nervous system of Lymnaea stagnalis.

: The passive electrical characteristics of four giant neurones in the CNS of Lymnaea stagnalis were studied. The parameters were calculated on the basis of potential transients evoked by hyperpolarizing square impulses. The examined neurones can be classified in two groups, which show significant differences considering the time constant and membrane resistance. This classification is in correlation with the functional properties of the cells. The differences in the passive electrical characteristics of the giant neurones were compared to some data obtained by using voltage clamp method. The role of these parameters in the generation of the single spike and the rhythmic discharge is discussed.