BIO304H5 Lecture 8: BIO304 Lecture 8 (1)
Document Summary
All ions must flow into pipette - voltage can be measured with amplifier connected to pipette. Called cell attached patch clamp recording method. Technique used to compare response characteristics of different channels. Close correlation in microscopic and macroscopic sodium currents - most channels open in initial 1-2 seconds following depolarization of membrane. Probability of channel opening diminishes because of channel inactivation. Consolidating currents recorded using the voltage-clamp with single channel currents. Permits recording of single ion channel currents. Technical modification enhanced the patch clamp technique. Single cell - use microscope to establish gigaohm seal. Resistance between rises the gigaohm - very high resistance. Cell-attached patch configuration - allows to record macroscopic currents because can record all ion channels present in cell. If membrane hatch in pipette is disrupted by strong suction - inside of pipette is continuous with cytoplasm - allows measurements of currents and electrical potential of whole cell.
