The limbic system consists of the parts of the brain that regulate memory motivation, and emotion. Although researchers aren't quite sure if all the structures are actually "limbic" or even if they form a "system." The key structures researchers think form the limbic system: thalamus, the amygdala, the hippocampus, and the hypothalamus. .
The thalamus or the "inner chamber" is a sensory relay station. It directs neural traffic between the senses and the cerebral cortex. All the things that you see, hear, taste, and touch is received here, and then processed and sent on to the appropriate region of the cortex. It's interesting that the sense of smell completely bypasses the thalamus because it has its own relay station that directs input from the nose to the olfactory bulb, which sits near areas that control emotion. This might explain why certain cologne might make you angry about a break up with a boyfriend in the past. Or the smell of cookies brings back certain emotions in us.
The amygdala is also called the aggression center because it is known to trigger the roots of aggression. In 1937 psychologist Heinrich Kluver and neurosurgeon Paul Bucy found that lesions of the temporal lobe, including the amygdala calmed ferocious rhesus monkeys. .
The Hippocampus is the largest structure in the limbic system. The hippocampus is a big part in the formation of new memories. In humans, brain scans reveal that the hippocampus area is smaller in people with severe memory loss, even while surrounding areas of the brain are intact. .
The hypothalamus "below the thalamus" regulates the body's endocrine system by triggering the release of hormones into the bloodstream. By doing so it helps regulate the basic emotions such as fear, rage, and also involved in drives such as hunger, thirst, sleep, and sex. You wouldn't want to get rid of the hypothalamus because it is also the home to your "pleasure centers.
