a computer simulation of experiments which may be performed on cat sciatic nerve-tibialis anterior muscle in vivo to teach the essentials of neuromuscular pharmacology

David Dewhurst, Godfrey Collins and Stewart Cromar

An interactive, menu driven and easy to use program which simulates experiments performed on the sciatic nerve-anterior tibialis muscle preparation of the cat (in vivo) to illustrate the important differences in the pharmacological action of depolarizing and non-depolarizing blocking agents.

An on-screen student handbook covers:

• an outline, using text and graphics of the process of neuromuscular transmission
• the preparation of the anaesthetised cat,
• the protocol for sciatic nerve stimulation and isometric recording of evoked contractions of the anterior tibialis muscle.
• a summary of the actions of the different types of blocking agents
• theclinical relevance of the different blocking agents.
  

The Experiments Section presents high-resolution graphic simulations of experimental results (muscle contractions), in accelerated time, on a scrolling display to simulate a chart recorder.

Phase I experiments - each experiment compares the action of the two types of neuromuscular blocking agent using d-tubocurarine as an example of a non-depolarizing blocker and decamethonium as an example of a depolarizing blocker.

• administeredi.v.
• administeredclose arterially
• inconjunction with an anticholinesterase
• inconjunction with a different competitive (non-depolarizing)
• blocker
• inconjunction with a different depolarizing blocker
• inresponse to tetanic stimulation
• inresponse to acetylcholine administered by close arterial injection.
  

Phase II experiments

• the effects of four successive doses of decamethonium followed by the effects of tetanic stimulation and an anticholinesterase
  

Student Activities
Each experiment has an associated student activity designed to assess understanding of the experimental results. These might be a series of true/false statements or a table to complete.There are also some suggested questions which would form the basis of a report of the experiment.

Click on one of the above screen grabs to see full size image.