Lesion Study Quiz

What is the role of the Suprachiasmatic nucleus (SCN) in mammals?

• Regulating body temperature

• Controlling hormone release

• Tracking day/night cycles

• Controlling feeding patterns

Which gene mutation is responsible for the altered free-running period in Tau mutant hamsters?

• Casein Kinase 1 (CK1)

• Retinoblastoma (RB)

• Tumor protein p53 (TP53)

• Fibroblast growth factor receptor 3 (FGFR3)

What is the free-running period of a homozygous Tau mutant hamster?

• Approximately 24 hours

• Approximately 22 hours

• Approximately 20 hours

• Approximately 18 hours

What is the purpose of lesion experiments in studying the SCN?

• To determine the role of the SCN in circadian rhythms

• To investigate the effects of anesthesia on hamsters

• To study the genetic mutations in hamsters

• To observe the feeding patterns of hamsters

What was the result of lesioning the SCN in a wild-type hamster?

• The hamster became arrhythmic

• The hamster showed a longer free-running period

• The hamster exhibited abnormal feeding patterns

• The hamster's body temperature increased

What did the transplant experiments using SCN tissue from wildtype hamsters reveal?

• The SCN is not necessary for behavioral rhythmicity

• The SCN determines the period of behavioral rhythms

• The SCN is responsible for hormone release

• The SCN is only a part of the pathway from the core clock to behavioral output

What was the purpose of using a permeable capsule in the modified transplant experiment?

• To prevent the donor SCN cells from forming new synaptic connections

• To enhance the formation of new synaptic connections between donor and host

• To isolate the donor SCN cells from the rest of the brain

• To measure the release of small molecules and diffusible signals from the donor SCN cells

What is the effect of SCN lesions on the circadian rhythms in mammals?

• They lengthen the period of circadian rhythms

• They shorten the period of circadian rhythms

• They abolish circadian rhythms

• They have no effect on circadian rhythms

What is the role of Casein Kinase 1 (CK1) in the circadian clock?

• It regulates the period of the circadian clock

• It is responsible for the entrainment of the circadian clock

• It is involved in the photic input pathway to the circadian clock

• It is not involved in the circadian clock