The Visual System 2 - Phototransduction

Question 1

Recall the difference between ON bipolar cells and OFF bipolar cells

Answer 1

ON bipolar cells are activated by an increase in light intensity

When light levels increase, ON bipolar cells become depolarized and release more neurotransmitters onto their target cells, which are typically ganglion cells in the retina

OFF bipolar cells are activated by a decrease in light intensity

When light levels decrease, OFF bipolar cells become hyperpolarized and release fewer neurotransmitters onto their target cells

Question 2

Recall the basic elements of the bipolar cell receptive field

Answer 2

Retinal ganglion cells will only fire action potentials when specific areas of the retina are illuminated

Bipolar cells have centre-surround organisation