Papez circuit

The **Papez circuit** is a loop of interconnected brain structures primarily in the medial temporal lobe and diencephalon and is considered a fundamental component of the limbic system[1][2][3][4]. Originally described by James Papez in 1937, it was proposed as the neural basis for emotional experience, although current understanding emphasizes its critical role in **memory processing and storage, particularly episodic memory**[2][3][5][6]. The circuit classically includes the hippocampal formation (subiculum), fornix, mammillary bodies, mammillothalamic tract, anterior thalamic nucleus, cingulate gyrus, cingulum, entorhinal cortex, and loops back to the hippocampal formation[1][2][3][6]. The Papez circuit is not a molecule or single receptor but a system-level anatomical pathway; thus, it is not considered a therapeutic target in the molecular sense and does not interact with drugs or have classic mechanisms of action, biomarkers, or safety concerns as seen with drug targets. Damage or dysfunction in this system is associated with **disorders of memory such as Alzheimer's disease, Parkinson's disease, Korsakoff syndrome, and other memory or affective disorders**[5]. **Note:** The Papez circuit is not a molecule, receptor, enzyme, or other druggable target, but rather a macroanatomical brain circuit. For drug and biomarker information, refer to its component structures (e.g., hippocampus, anterior thalamic nucleus) or conditions affecting it.

Other names

Medial limbic circuit