Find infected brains is an objective in the Story Mission, Spore Chores in Borderlands 2: Commander Lilith and the Fight For Sanctuary
- Start along the walkway to the East, going into the first open area of it.
- A number of New Pandora Troops will attack: New Pandora Surgeons, New Pandora Private, and New Pandora Pandemicist.
- There will be 2 Infected Sprouts.
- Killing them you will get 2 Infected Brain Samples.
- Having cleared out the foes here, head up the stairs to the South.
- In this section of the Walkway, more New Pandora Privates, and New Pandora Marksman.
- Defeat all of the Marksman and then go to the North.
- Pull the switch next to the raised bridge to see a pull switch.
- This will lower the bridge to reach the next section of the walkway.
- Here you will encounter New Pandora Infernos, Marksman, and Privates.
- With the infected, you can encounter Saplings, and a pair of Infected Lesionaire.
- Defeat all of them, focusing on the Lesionaire, to collect the remaining brains that you need.