Author Question: Explain how the activity of brain cells is measured using autoradiography. What will be an ideal ... (Read 93 times)

Starlight · **on:** Jun 22, 2018

Explain how the activity of brain cells is measured using autoradiography.

What will be an ideal response?

Question 2

Explain the rationale behind the optogenetic methods.

What will be an ideal response?

cici · **Reply #1 on:** Jun 22, 2018

Answer to Question 1

Answer: Brain cells require glucose as fuel for activity. 2-DG, like glucose, is taken up into neurons, but cannot be used for energy. If a radioactive version of 2-DG is injected into an animal, radioactive 2-DG molecules will accumulate in the brain as a function of the relative activity of those cells. Autoradiography will reveal the presence of radioactive molecules in the brain, with a more intense signal in regions that were more active and a less intense signal in less active regions.

Answer to Question 2

Answer: The method can be used to stimulate or inhibit neurons in a specific brain region. Two distinct photosensitive proteins have been identified. ChR2 controls a sodium channel and is sensitive to blue light. NpHR controls a chloride channel and is sensitive to yellow light. The proteins are inserted into a brain region and the response to blue or yellow light is noted. Typically, blue light activates and yellow light inhibits neuron activity.