Introduction Function the limbic system is involved in Homeostasis Olfaction Memory Emotions and drives mnemonic "HOME" Anatomy the main components of the limbic system includes limbic cortex hippocampal formation involved in learning and memory amygdala involved in emotions and drives olfactory cortex hypothalamus thalamus Papez circuit although it overly simplifies the circuitry of the limbic system, it is a useful way to expose yourself to this circuitry fibers from the hippocampal formation enter the fornix to reach the lateral and medial mammillary nuclei fibers from the medial mammillary nuclei project to the anterior nucleus of the thalamus (via the mammillothalamic tract), which subsequently project fibers to the cingulate gyrus after passing through the internal capsule fibers from the cingulate gyrus then project to the parahippocampul gyrus and then to the enterrhinal cortex and finally to the hippocampal formation Clinical correlate anterograde amnesia this describes a deficit in forming new memories and can be seen in bilateral medial temporal lobe damage Wernicke-Korsakoff syndrome this is caused by thiamine deficiency and results in bilateral necrosis of the mamillary bodies (in most cases) these patients typically present with the triad of ataxia eye movement abnormalities (e.g., ophthalmoplegia) confusion after the patient survives the acute stages of this disease, they can develop anterograde and retrograde amnesia Kluver-Bucy syndrome this results from bilateral lesions of the amygdala and adjacent temporal lobe structures, which results in placidity decreased aggressive behavior and having little emotional reaction psychic blindness hyperorality hypersexuality Schizophenia defective dopaminergic signaling in the mesolimbic pathway (ventral tegmental area of the midbrain to the ventral striatum) responsible for positive psychotic symptoms (e.g., delusions, hallucinations)