【速報】一度つらい目にあうと次のストレスに弱くなる。その「増幅回路」をマウスで発見

Q1. What is the passage mainly about?

1. AHow to keep mice as pets
2. BWhy people like scary movies
3. CA brain part that makes stress feel stronger after hard experiences
4. DHow to stop feeling hungry

つらい経験のあとストレスへの反応を強める脳の部分についての研究なので C が正解。

Q2. What happened when the scientists stopped the signals?

1. AThe mice became more afraid.
2. BThe mice forgot everything.
3. CThe amygdala grew bigger.
4. DThe strong reaction went away.

When the scientists stopped these signals, the strong reaction went away. とあるので D。

Q3. In this passage, "upset" is closest in meaning to ...

1. Aworried or unhappy
2. Bvery hungry
3. Cfull of energy
4. Dsleepy

upset は「動揺した、気が動転した」。worried or unhappy（心配な、不幸な）が最も近いので A。

Q1. What were the researchers trying to find out?

1. AWhat changes in the brain make stressed individuals more sensitive to later stress
2. BHow to make mice live longer
3. CWhich foods reduce stress in humans
4. DWhy some mice are larger than others

To find out what changes in the brain ... とあり、過去のストレスで敏感になる脳の変化を探っているので A。

Q2. Which statement about the anterior hypothalamic nucleus is true?

1. AIt has always been the main focus of stress research.
2. BIt is part of the amygdala.
3. CIts cells reacted more strongly as experiences became more unpleasant.
4. DIt became less active after stress.

Its nerve cells responded more strongly as experiences became more unpleasant とあるので C。had received little attention とあるので A は誤り。

Q3. What does the writer suggest at the end of the passage?

1. AMice should never be used in research.
2. BThe circuit might help scientists develop new treatments.
3. CStress is always good for the brain.
4. DThe amygdala is not related to fear.

最終文 This circuit could become a target for future treatments. から B。

Q1. What is the main point of the passage?

1. AMice are less sensitive to stress than humans.
2. BThe amygdala is the only brain area involved in fear.
3. CLaboratory stress is the same as human trauma.
4. DA newly highlighted brain circuit may explain why past stress increases later sensitivity.

過去のストレスで後のストレスに敏感になる仕組みとして、扁桃体から前視床下部核への回路を示した研究なので D。

Q2. How did the team confirm that the region played a causal role?

1. ABy asking mice how they felt
2. BBy suppressing and activating its neurons
3. CBy removing the amygdala completely
4. DBy comparing mice of different sizes

Manipulating these neurons in both directions confirmed a causal role: suppressing ... activating ... とあるので B。

Q3. Which statement would the author most likely agree with?

1. AIt is still uncertain whether the same circuit works in humans.
2. BThe study proves a cure for depression has been found.
3. CHuman trauma and laboratory stress are identical.
4. DThe anterior hypothalamic nucleus has been well studied for decades.

最終文 Whether a comparable circuit plays the same role in the human brain has yet to be established. とあるので A。