Mechanoreceptors
Mechanoreceptors¶
Before starting this lab, you should be familiar with:
- What an action potential is
- The basics of electrophysiology
- How measuring action potentials from either inside or outside of a cell affects the data collected
- The basic anatomy of the cockroach leg and nervous system
- Trial-based experimental design
Most of the largest sensory neurons in the cockroach leg detect movements of the spines (“bristles”). When the spine is pushed from its resting position, the opening of mechanically sensitive ion channels produces a transduction current that changes the membrane potential of the mechanoreceptor cell. The number of action potentials (spikes) produced by the mechanoreceptors is proportional to the amount of depolarization. Mechanotransducers also occur in the lateral line receptors of fish, touch receptors in skin, and auditory (“hair cell”) receptors.
Often, a neurophysiologist does not need to know the actual changes in a neuron’s membrane potential, but only when an action potential occurs. In this case, an extracellular recording is usually adequate.
You will use extracellular recording techniques to explore the response properties of spine mechanoreceptors in the cockroach leg.