Why did destroying the septal area make rats furious, while stimulating it made them seek more? · Grey Matter

The lateral septum sends largely inhibitory projections to the hypothalamus and other regions that generate defensive and aggressive behaviour, so it acts as a brake on how strongly an animal reacts.

Why did destroying the septal area make rats furious, while stimulating it made them seek more?

The lateral septum sends largely inhibitory projections to the hypothalamus and other regions that generate defensive and aggressive behaviour, so it acts as a brake on how strongly an animal reacts. Brady and Nauta found in 1953 that rats with septal lesions attacked or startled at harmless handling, the brake gone, an effect that fades over weeks. In 1954 Olds and Milner found that rats would press a lever repeatedly to stimulate electrodes in or near the septal area, the first evidence of reward sites in the brain, later traced mostly to the medial forebrain bundle that runs nearby toward the hypothalamus.