Question 119

Question:

A neuroscientist conducting experiments on the function of various hypothalamic nuclei uses an electrode to burn a small lesion in a rat’s brain. Over the next few weeks, the rat begins to eat uncontrollably and increases its mass by 60%. What hypothalamic nucleus was ablated?

Correct Answer: E.  Ventromedial nucleus

The ventromedial nucleus is responsible for giving a sense of satiety; its destruction would cause hyperphagia. By contrast, the lateral nucleus is responsible for the feeling of hunger.
The septate nucleus is involved in sexual functioning. The suprachiasmatic nucleus helps control the circadian cycle. The anterior nucleus helps control parasympathetic tone and to cool the body when it is hot.
Knowledge of the hypothalamic nuclei may seem esoteric, but is actually frequently tested on the USMLE.