Fornix
The so-called fornix consists of a pronounced fibrous cord that connects the hippocampus with the mammillary corpus above the third ventricle. As part of the functional circuit known as the “limbic system“, the fornix is also involved in the transfer of information from short-term to long-term memory.
Corpus mamillare
The corpus mamillare is a paired part of the limbic system located on the underside of the brain between the two cerebral legs. The corpus mamillare is directly connected to the so-called Papez neuron circle via dense fiber trains. The previously assumed function of this structure is now being questioned, since it is assumed that it is not the corpus mamillare itself but the amygdala that is responsible for the essential control of emotional processes.
Corpus amygdaloideum (Amygdala)
The corpus amygdaloideum (amygdala) is a paired nucleus located in the middle part of the temporal lobe. From a functional point of view, the amygdala belongs to the functional unit known as the “limbic system“. An important function of the amygdala is the control of emotional influences.
It is said to be involved in the development of feelings of anxiety and the evaluation of emotional situations. In general, the corpus amygdaloideum evaluates external impulses and initiates vegetative reaction patterns adapted to them.A loss of function of this part of the limbic system results in a pronounced loss of anxiety sensations. In this way, damage to the amygdala results in the loss of vital warning and defense reactions. Furthermore, it is now assumed that the amygdala exerts a decisive influence on the sex drive. Typical diseases that are related to damage and/or malfunction of this part of the limbic system are memory disorders, autism, depression and phobias.
Gyrus cinguli
The gyrus cinguli (synonym: belt winding) forms the inner part of the cerebrum. As a belt-shaped structure it rests on the beam and runs from the forebrain to the back. On the cellular level, this structure of the limbic system can be divided into an anterior (pars posterior) and a posterior (pars posterior) area.
In functional terms, the posterior cinguli gyrus is in close contact with nerve cells of the forebrain, especially with the temporal and frontal lobes. This area is involved in the control of spatial memory in cooperation with the hippocampus. The anterior cinguli gyrus forms a network with the amygdala, the hippocampus, the nucleus accumbens, the thalamus and the islet cells. Its most important task is to weigh contradictory impulses against each other and ultimately to make a decision for action.