The limbic system is a group of structures in the brain. These structures cover both sides of the thalamus, right under the cerebrum. It is not a separate system, but a collection of structures from the cerebrum, diencephalon, and midbrain. These structures include the hippocampus, amygdala, hypothalamus, cingulate gyrus, nucleus accumbens and part of the thalamus. It supports many different functions, including emotion, behaviour, motivation, long-term memory, and olfaction.