Mechanical changes in crab nerve fibers during action potentials
Related Experiment Video
Updated: Aug 18, 2026

Physiological Recordings of High and Low Output NMJs on the Crayfish Leg Extensor Muscle
Published on: November 17, 2010
Abstract:
A nerve impulse travelling along a crustacean nerve was found to be accompanied by a small, rapid movement of the nerve surface. The movement was 10-20 nm in amplitude and was concurrent with a rise in the "swelling pressure" of the order of 5 mg/cm2 for a nerve bundle. Initiation of an action potential at the site of cathodal polarization was preceded by a small, slow mechanical change in the nerve fiber. Anodal polarization produced a large mechanical change of the opposite sign. Tetrodotoxin and procaine suppressed rapid mechanical changes.
More Related Videos
16:16Membrane Potentials, Synaptic Responses, Neuronal Circuitry, Neuromodulation and Muscle Histology Using the Crayfish: Student Laboratory Exercises
Published on: January 18, 2011
10:50Muscle Receptor Organs in the Crayfish Abdomen: A Student Laboratory Exercise in Proprioception
Published on: November 18, 2010
Related Concept Videos
Action Potentials
Action Potential
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...
Generation of Action Potential in Skeletal Muscles
Like neurons, muscle cells are also regarded as excitable due to their capacity to change in response to stimuli, primarily due to voltage-gated ion channels embedded in their plasma membranes, which get activated by alterations in the cell's...
Relaxation of Skeletal Muscles
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open.
Motor Unit Stimulation
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
Action Potential
Membrane potential in neurons
Neurons typically have a resting membrane potential of about -70 millivolts (mV). When they receive...