Queston #6767Note

The Papez circuit has been considered a fundamental part of the limbic system. Although initially felt to play the prime role in emotional regulation, it is actually now known to have a large and likely dominant role in memory. The revised Papez circuit included the amygdala, which is felt to be a large component of emotional regulation, but the original circuit did not include this organ. The original Papez circuit proceeds as follows: Hippocampus → fornix → mammillary body → mammillothalamic fibers→ thalamus (anterior nucleus) → cingulum→ entorhinal cortex → hippocampal formation.

The anterior thalamus is involved in the Papez circuit, while the posterior thalamus, including the pulvinar nucleus, is not involved. It is likely for this reason that “thalamic amnesia,” a complication of lacunar stroke in the thalamus, occurs when the damage is to the anterior thalamic structures.