Q49.1-4ITD - Campbell Biology

Question

In 20% of the hamsters, there was no restoration of rhythmic activity following the SCN transplant. What are some possible reasons for this finding? Do you think you can be confident of your conclusion about the role of the SCN based on data from 80% of the hamsters?

Step-by-Step Solution

Answer

The transplanted SCN may not have developed functional connections with the recipient's brain in the 20% of cases.

However, the data from 80% of the hamsters were very consistent.

Step 1: Rhythmic activity of the brain

In rhythmic activity, the brain controls physical movements like sounds, pulses, or music. These rhythmic activities rely on the internal and external rhythm for expression, behavior socialization, and cultural expression.

Step 2: Restoration of rhythmic activity by SCN transplants

The SCN (suprachiasmatic nucleus) of the host transplanted restores the foetus' hypothalamic tissue's circadian locomotion cycle. These transplants contain an extra amount of substantial hypothalamic SCN tissues. 

The findings from the given experiment suggest that SCN-only transplants are necessary and sufficient for restoring circadian locomotor activity patterns.

Step 3: Possible reasons for no restoration activity in 20% of hamsters

The possible reason why there was no restoration in the rhythmic activity of the SCN after transplantation could be because the recipient’s brain has not produced connections with the SCN transplants in 20% of the hamsters.

Thus, there was no restoration of rhythmic activity in 20% of the hamsters due to the given reasons. The data acquired from the remaining 80% of the hamsters, on the other hand, was consistent, and the link between rhythmic activity was restored.