SCN Neurons Are the 'Pacemaker Cells' for the Circadian Rhythm

question 15

Multiple Choice

SCN neurons are the 'pacemaker cells' for the circadian rhythm. Circadian rhythms can be altered by the time of day, for example when you travel and go to a new time zone your clock has to reset. How do neurons in your SCN receive information about daylight?

• A) They receive information from cryptochrome-containing cells in skin.
• B) They receive direct input from intrinsically photosensitive retinal ganglion cells.
• C) They receive input from neurons in the visual cortex.
• D) There is no direct input about daylight to the SCN. When the animal is in darkness for longer the phase of the SCN neurons advances to adjust to the new time zone.

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