Slide 9

Intracellular recording from a cortical pyramidal cell during presentation of a 10% followed by 60% contrast grating exhibits strong contrast adaptation, as indicated in the peristimulus histogram. Following return to the low contrast stimulus, the membrane potential is strongly hyperpolarized and slowly recovers over the next 20-30 seconds. Bottom Trace: Raw intracellular recording from a cortical simple cell illustrating the hyperpolarization of the membrane potential with presentation of a 40% contrast grating. Note the repolarization of the membrane potential in between presentations of the high contrast stimlulus.