Easy method to examine single nerve fiber excitability and conduction parameters using intact nonanesthetized earthworms.

ABSTRACT: The generation and conduction of neuronal action potentials (APs) were the subjects of a cell physiology exercise for first-year medical students. In this activity, students demonstrated the all-or-none nature of AP generation, measured conduction velocity, and examined the dependence of the threshold stimulus amplitude on stimulus duration. For this purpose, they used the median giant nerve fiber (MGF) in the ventral nerve cord of the common earthworm (Lumbricus terrestris). Here, we introduce a specialized stimulation and recording chamber that the nonanesthetized earthworm enters completely unforced. The worm resides in a narrow round duct with silver electrodes on the bottom such that individual APs of the MGF can be elicited and recorded superficially. Our experimental setup combines

SUBMITTER: Bahring R 

PROVIDER: S-EPMC4154267 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature