Papez circle
The Papez circle is a theory developed by James W. Papez in 1937 , which initially attempted a neurofunctional explanation only for the emergence of emotions , and was only later recognized as the most important basis for consolidating learned memory contents from short to long-term memory. The corpus mamillare plays a central role in this concept . In 1949 Paul MacLean corrected Papez's ideas and introduced the term limbic system .
The Papez circle is a chain of neurons with the following course:
- The hippocampus projects from its components gyrus dentatus and subiculum over the fornix into the corpus mamillare.
- From here the neurons project via the mamillothalamic fasciculus (also called the “ Vicq d'Azyr bundle”) into the anterior thalami nucleus , and from there via the thalamocingular tract to the cingulate gyrus .
- Via a fiber tract located deep in the cingulate gyrus, the cingulum , it goes to the entorhinal area in the parahippocampal gyrus and back to the hippocampus via the perforans tract , which closes the circle.
Although only a fraction of the fibers return to the hippocampus, the loop is flush.
This loop is regulated by the neocortex , which is bidirectionally connected to the cortex of the cingulate gyrus. This can lead to the retrieval of information that has already been saved and new information to be saved. In the neocortex, the emotion is also given a personal color and is therefore unconsciously evaluated.
The neuron circuit serves to maintain recent memory content, which promotes primary to secondary or tertiary memory. Failures of even individual parts of one of the members of this circle (gyrus parahippocampalis, hippocampus, fornix, corpora mamillaria, anterior core of the thalamus) cause anterograde amnesia , with long-term memory preserved.
literature
- Martin Trepel: Neuroanatomy . 5th edition (2012). Urban & Fischer Verlag.
Individual evidence
- ^ Mark F. Bear, Michael A. Paradiso, Barry W. Connors: Neuroscience: Exploring the Brain 2006, Lippincott Williams & Wilkins, p. 569