Welcome to Bioc 415

• Brief description & policies
• Assignments

Course activities

• First session
• Membrane labs
• Nerve labs
• Nerve/muscle labs

On-line resources

Introductory lab manual (Bioc 211)
Bioc 311 resources

Bioc 415 manual (pdf)

Bioc 415 appendixes (pdf)

Experimental Physiology: Nerve Labs

Pre-lab discussion (Monday 12 Sep – 1 pm ABL 329)

• Discuss results from variable potassium and sodium studies
• Review principles behind the equilibrium and diffusion potential models
• Questions on stability of the membrane potential, effect of raising P_Na
• Action potential initiation and propagation
• Compound action potential of a nerve trunk
• Why the equilibrium model was ultimately rejected

Laboratory (GRB W112)

You will learn to record very fast events during a self-paced tutorial on using the ADInstruments Scope recording software.

Preparation for next time

• Continue reading chapter 2 of the manual up to page 23, conduction velocities
• Know the temporal and spatial relationships among stimulus and recording electrodes, stimulus artifact, and components of a propagated compound action potential
• Prepare an experimental design to study recruitment of nerve axons
• Prepare an experimental design to study the relationship between stimulus voltage and duration; address the question: can a threshold stimulus be defined by the equation, voltage x duration = k?
• NOTE: The first research paper will be due in class two weeks from today (Monday 26 Sep)

Pre-lab discussion (Wednesday 14 Sep – 1 pm GRB W100)

• Discussion: compound action potential features and relationship to artifact, stimulus, electrodes
• Stimulus thresholds and terminology to be used
• Significance of a recruitment curve
• Significance of the strength-duration relationship
• Suggestions for conducting the experiments and for collecting data

Laboratory (GRB W112)

• Demonstration – dissecting a frog to obtain a sciatic nerve, preparing a nerve chamber, recording a compound action potential
• Obtain and mount a sciatic nerve, record a compound action potential, obtain recruitment data
• Obtain data with which to analyze the strength-duration relationship

Preparation for next time

• Finish reading the manual chapter 2
• Prepare an experimental design with which to estimate conduction velocities
• [ASSIGNMENT] Prepare an experimental design with which to estimate a relative refractory period
• Be prepared for a possible quiz on the reading and/or subject matter covered today

Pre-lab discussion (Monday 19 Sep – 1 pm ABL 329)

• Discuss the recruitment and strength-duration data
• Myelination, saltatory conduction, and safety factor
• Bases for relative and absolute refractory periods
• Suggestions for conducting the experiments and for collecting data

Laboratory (GRB W112)

• Estimate conduction velocities, preferably for more than one axon type
• Obtain an estimate of refractory period for the least refractory axons
• Test the hypothesis that a suprathreshold stimulus reduces the duration of a relative refractory period
• Explore the consequences of blocking nerve conduction with lidocaine

Preparation for next time

• Conduct a preliminary analysis of the data including an estimate of conduction velocity and an estimate of refractory period
• Read chapter 3 of the manual through the material on muscle tetanus
• [ASSIGNMENT] Prepare an experimental design with which to observe Treppe, incomplete and incomplete tetanus
• [ASSIGNMENT] Prepare an experimental design with which to study recruitment of motor units, including the relationship between muscle compound action potential and muscle tension
• Be prepared for a possible quiz on the reading and/or subject matter covered today