[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Physiology](https://durgical.com/en/physiology/) › [Neurophysiology](https://durgical.com/en/physiology/#s-neuro) › The limbic system, emotion and reward [Physiology](https://durgical.com/en/physiology/) · [Neurophysiology](https://durgical.com/en/physiology/#s-neuro) # The limbic system, emotion and reward - Concept - For completeness A ring of brain structures links feelings, memory and motivation, and drives the body's emotional reactions. Updated 2026-11-01 Also called: Papez circuit, Reward pathway **See it in 3D:** [Amygdala](https://durgical.com/en/anatomy/amygdaloid-body/) · [Hippocampus](https://durgical.com/en/anatomy/hippocampus/) · [Cingulate gyrus](https://durgical.com/en/anatomy/cingulate-gyrus/) · [Fornix](https://durgical.com/en/anatomy/fornix/) · [Hypothalamus](https://durgical.com/en/anatomy/hypothalamus/) · [Thalamus](https://durgical.com/en/anatomy/thalamus/) · [Frontal lobe](https://durgical.com/en/anatomy/superior-frontal-gyrus/) ## Key points - Amygdala: fear, threat detection and emotional learning; bilateral damage causes Klüver–Bucy syndrome (placidity, hyperorality, hypersexuality, visual agnosia). - Papez circuit: hippocampus → fornix → mammillary bodies → anterior thalamus → cingulate gyrus → back to hippocampus. - Reward: dopamine neurons of the ventral tegmental area project to the nucleus accumbens; drugs of abuse raise dopamine there. - The hypothalamus is the output: emotion produces autonomic (heart rate, sweating) and endocrine (cortisol) changes. - Orbitofrontal and ventromedial prefrontal cortex regulate emotion and social behaviour; damage causes disinhibition. ## What it is The limbic system is a set of structures on the inner edge of each hemisphere: hippocampus, amygdala, cingulate gyrus, fornix, mammillary bodies and connected thalamic and prefrontal areas. It gives emotional value to experience, links emotion with memory, and acts on the body through the hypothalamus. The mesolimbic dopamine pathway signals reward and drives motivated behaviour. ## Key facts - Dopamine in the reward pathway encodes prediction error: it rises when an outcome is better than expected. - The amygdala receives fast, crude sensory input from the thalamus and slower, detailed input from the cortex, allowing quick reactions to threat. - Smell connects directly to amygdala and entorhinal cortex, which is why odours evoke strong emotional memories. - Herpes simplex encephalitis targets the medial temporal and orbitofrontal regions and can produce Klüver–Bucy features. ## Clinical notes - Addiction: repeated drug-induced dopamine surges remodel reward circuits and weaken prefrontal control. - Temporal lobe seizures often start in the hippocampus or amygdala: déjà vu, fear, rising epigastric sensation, smells. - Chronic stress and depression are linked to changes in hippocampal volume and amygdala reactivity. ## Memory aid The amygdala is the smoke alarm, the hippocampus the archivist, the hypothalamus the hands that act, and the prefrontal cortex the adult in the room. ## Test yourself Think of the answer, then tap the question to see it. ## Which circuit connects the hippocampus to the cingulate gyrus, and through which structures? The Papez circuit: hippocampus → fornix → mammillary bodies → mammillothalamic tract → anterior thalamic nucleus → cingulate gyrus → parahippocampal cortex → hippocampus. ## Why does fear raise heart rate and blood pressure? The amygdala activates the hypothalamus and brainstem autonomic centres, increasing sympathetic outflow and adrenal catecholamines and engaging the stress axis. ## How do drugs of abuse act on the reward pathway? They increase dopamine in the nucleus accumbens, directly or by disinhibiting ventral tegmental neurons, producing a reward signal larger than natural rewards. ## What does bilateral amygdala damage produce? Klüver–Bucy syndrome: loss of fear and placidity, hyperorality, hypersexuality and inability to recognise the meaning of objects seen. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/physiology/the-limbic-system-emotion-and-reward/) ## See it in 3D The structures of Durgical's 3D anatomy where it happens. - [Amygdala](https://durgical.com/en/anatomy/amygdaloid-body/) - [Hippocampus](https://durgical.com/en/anatomy/hippocampus/) - [Cingulate gyrus](https://durgical.com/en/anatomy/cingulate-gyrus/) - [Fornix](https://durgical.com/en/anatomy/fornix/) - [Hypothalamus](https://durgical.com/en/anatomy/hypothalamus/) - [Thalamus](https://durgical.com/en/anatomy/thalamus/) - [Frontal lobe](https://durgical.com/en/anatomy/superior-frontal-gyrus/) ## Related topics - [Learning and memory](https://durgical.com/en/physiology/learning-and-memory/) - [Functions of the hypothalamus](https://durgical.com/en/physiology/functions-of-the-hypothalamus/) - [The main neurotransmitters](https://durgical.com/en/physiology/the-main-neurotransmitters/) - [Taste and smell](https://durgical.com/en/physiology/taste-and-smell/) - [The HPA axis and its circadian rhythm](https://durgical.com/en/physiology/the-hpa-axis-and-its-circadian-rhythm/) ## Related conditions - [Epilepsy and seizures](https://durgical.com/en/conditions/epilepsy-and-seizures/) - [Alzheimer disease](https://durgical.com/en/conditions/alzheimer-disease/) ## In Biochemistry - [Catecholamines: synthesis and breakdown](https://durgical.com/en/biochemistry/topics/catecholamines-synthesis-and-breakdown/) ## In Pharmacology - [Opioids and antagonists](https://durgical.com/en/pharmacology/classes/opioids-and-antagonists/) [← All of physiology](https://durgical.com/en/physiology/) Educational physiology content; not a diagnostic or treatment guide and no substitute for a health professional's advice. Values are approximate references. No doses are given. Sources: [13.2 The Central Nervous System](https://openstax.org/books/anatomy-and-physiology-2e/pages/13-2-the-central-nervous-system/) (OpenStax (Rice University), 2022); [Neuroanatomy, Limbic System](https://www.ncbi.nlm.nih.gov/books/NBK538491/) (StatPearls (NCBI Bookshelf), 2024); [Neuroanatomy, Amygdala](https://www.ncbi.nlm.nih.gov/books/NBK537102/) (StatPearls (NCBI Bookshelf), 2024); [Neuroanatomy, Cingulate Cortex](https://www.ncbi.nlm.nih.gov/books/NBK537077/) (StatPearls (NCBI Bookshelf), 2024); Hall JE. Guyton and Hall Textbook of Medical Physiology, 13th ed. (ch. 59). Reference book used to check facts; its text and figures are not reproduced (Elsevier, 2016). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/physiology/the-limbic-system-emotion-and-reward/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/physiology/the-limbic-system-emotion-and-reward/