The Limbic system and the Basal Ganglia

The limbic system

The limbic system has an effect on our memory and emotions.

The limbic system is located deeply in the cerebrum on the inside of the temporal lobe and includes, among other things, the hippocampus (Latin for seahorse) and the amygdala.

Amygdala is important for processing emotions, as fear. Amygdala can affect areas of the brain through adrenaline’s release, stress hormone, in fear. It provides reactions such as palpitations, high blood pressure and intense awareness. The amygdala also has an effect on the emotions that are attributed to sensory impressions before they are transferred to memory.

Hippocampus is very important for learning from new experiences and sensory impressions, because without it you cannot store new information. People who suffer from hippocampus’ damage on both sides of the brain may well recall events from before the injury, but immediately forget what they are receiving from new information.

The most characteristic and earliest symptom of Alzheimer’s disease is the inability to store new information, because it starts from areas around hippocampus.

The basal ganglia

They are part of the big brain and have an effect on our control of movement and intellectual functions.

Deep in the cerebrum are bounded structures that are part of the networks, which connect cerebral areas to each other. The basal ganglia is associated with the thalamus, a large nucleus of nerve cell, which is the most important switching center for the sensory impressions that reach the brain through the nerves of the spinal cord.

The basal ganglia is closely associated with nerve cells that produce the signal substance dopamine. If these nerve cells are destroyed, as for example in the case of Parkinson’s disease, an imbalance in the basal ganglia control of the movements become slow and rigid. The slow and stiff movements, which, among other things, cause a short-stepped gait and balance problems, can be seen in the dementia diseases affecting the basal ganglia. These include Lewy Body dementia, dementia in Parkinson’s disease and the atypical Parkinson’s disease.