Neuroanatomy of the Limbic System (OS 202) PDF

OS 202: HUMAN BODY AND MIND 1: INTEGRATION AND CONTROL SYSTEMS NEUROANATOMY OF THE LIMBIC SYSTEM UPCM 2029 | Dr. Jose Leonard V. Pascual | LU3 A.Y. 2024-2025 OUTLINE I.​ The Limbic System III.​ Areas of...

OS 202: HUMAN BODY AND MIND 1: INTEGRATION AND CONTROL SYSTEMS NEUROANATOMY OF THE LIMBIC SYSTEM UPCM 2029 | Dr. Jose Leonard V. Pascual | LU3 A.Y. 2024-2025 OUTLINE I.​ The Limbic System III.​ Areas of the Brain that A.​ Allocortex Like Food B.​ Mesolimbic System A.​ Cerebral cORTEX C.​ Structures in the Limbic B.​ Subcortical Gray System Matter (Basal Ganglia) II.​ Basic Instincts C.​ Brainstem A.​ Ventral Tegmental IV.​ References Area (VTA) and Eating B.​ Areas of the Brain that “Like” Food LEARNING OBJECTIVE Describe how limbic system structures interact with the cerebral Figure 2. Periallocortex cortex and autonomic nervous systems in terms of memory and ARCHICORTEX[2025 Trans] emotions ​ Hippocampus I.​ THE LIMBIC SYSTEM ○​ Has a role in memory, spatial navigation and control of attention ​ Limbic - rim or ring of structures inside the brain if you take out ROSTRAL MIDBRAIN the cerebral cortex ​ Ventral Tegmental Area (VTA) of the Midbrain ○​ Most of our emotions are located here ○​ Similar to Substantia Nigra ​ Structures in the brain that has three, four, or five layers ​ Both produces Dopamine ○​ Any structure in the brain that has less than six layers is part of ​ Some specimens have a dark VTA the limbic system ○​ Source that powers up your limbic system ​ Considered as the primitive brain ​ Produces dopamine but not for the basal ganglia motor system ○​ Not a very accurate description of the limbic system as it involves the brain’s center of emotions ​ It contains the following in the coronal cut of the forebrain[2028 Trans]: ○​ Insula to the base of the brain ​ The “brain of the brain” ○​ Substantia innominata ○​ Cingulate gyrus A.​ ALLOCORTEX[2025 Trans] ​ Among the two types of cerebral cortex (other type is neocortex) ​ Three subtypes of Allocortex: ○​ Paleocortex ○​ Periallocortex ○​ Archicortex Figure 3. Rostral Midbrain PALEOCORTEX B.​ MESOLIMBIC SYSTEM ​ Paleocortex: “Old Cortex” ○​ Oldest part of the brain ​ A CNS circuit in which the ventral tegmental area (VTA) produce ​ Found in the temporal lobe dopaminergic inputs to various brain regions[Serafini et al., 2020] ○​ Together with piriform cortex and olfactory bulb ​ Composed of the mesencephalon and the limbic system within the ○​ Contains Olfactory lobe where the olfactory nerves end up cerebral cortex ○​ Olfactory nerve: One of the oldest nerves ○​ Cerebral cortex ​ Forms a ring around the brainstem and telencephalon ○​ Limbic System ○​ Dopaminergic pathways Figure 1. Paleocortex Figure 4. Mesolimbic System PERIALLOCORTEX[2028 Trans] ​ More than three layers of cortex ​ Cortex around where the area with olfactory nerve is located ​ Transitional zone between the neocortex and allocortex [2027 Trans] ​ Periarchicortex ○​ One of the two subtypes of the periallocortex (the other being the peripaleocortex) ○​ aka entorhinal cortex in parahippocampal gyrus ○​ Has something to do with smell Figure 5. Mesolimbic Pathway[Mathias, 2023] Trans TG7: Chu, Chua, A., Chua, S., Claridad, Comia, Cornelio, Cortez TH: Tansiongco 1 of 8 #11  C.​ STRUCTURES OF THE LIMBIC SYSTEM CINGULATE GYRUS ​ Medial part of the brain ○​ Limited above by the cingulate sulcus ○​ Limited below by the corpus callosum Parts of the Cingulate Gyrus ​ Subgenual ○​ Helps someone think ○​ Next to genu of corpus callosum[2027 Trans] ​ Affective Division ○​ Responsible for exhibiting emotions ​ Cognitive Division ○​ Helps in decision-making processes ​ Posterior Division ○​ Sensory division ○​ Helps in understanding other people[2027 Trans] Figure 9. Posterior Cingulate Cortex ​ See Posterior Cingulate Cortex Paracingulate Sulcus and Gyrus ​ Necessary in distinguishing differences between reality and fantasy ​ Absent in 27% of people ​ Patients with schizophrenia were observed to have a smaller subgenual cingulate gyri and absent paracingulate gyri Figure 6. Parts of the Cingulate Gyrus[Koo et al., 2008] MNEMONIC ​ All The Cingulate (Single) Ladies Figure 10. Paracingulate Sulcus and Gyrus ○​ Cingulate = “Singsing” ​ The cingulate gyrus appears similar to a ring in the lateral view of the brain hemisphere Figure 11. Absence of Paracingulate Gyrus in Schizophrenic Patients Indusium Griseum (Supracallosal Gyrus) ​ Located above the corpus callosum and beneath the ventral cingulate gyrus ​ Thin layer of gray matter that is in contact with the dorsal aspect of the corpus callosum Figure 7. Cingulate gyrus Anterior Cingulate Cortex ​ Anterior portion of the Cingulate Gyrus ​ Involved in error and conflict detection[2028 Trans] ○​ Testmanship helps in choosing the best answer during multiple choice exams ○​ Moral decision-making (right vs. wrong) Figure 12. Indusium Griseum Vestigial extension of the hippocampus(2027 Trans) ​ Used to be a larger part of the hippocampus ​ “Forgotten hippocampus” ​ Embryonic development: Larger than hippocampus but is expected to shrink. Figure 8. Anterior Cingulate Cortex Posterior Cingulate Cortex (PCC) ​ Posterior portion of the Cingulate Gyrus ​ Functions: ○​ Acts on what is sensed or grasped about a situation ○​ Involved in the capacity to understand other people’s beliefs or empathize with other people ○​ Putting oneself into other people’s shoes Figure 13. Structures around the Indusium Griseum OS 202 Neuroanatomy of the Limbic System 2 of 8  ORBITOFRONTAL CORTEX ​ As seen in Figure 15, the association fibers (cingulum) are directed the same way and encircles the corpus callosum ​ Involved in decision-making based on risk, anticipated rewards, and ​ It is a ring emotions ○​ One continuous piece of tissue ​ The deciding piece of brain that uses probabilities of success/failure or guilt/pleasure Parahippocampal Cortex ○​ For assessing situations and reaching a decision ​ Association cortex of the cortex inside ○​ Expecting failures and successes, consequences ○​ The cortex inside is the hippocampus for short term memories ○​ What’s in it for me? ​ Parts of the PHC:[2026 Trans] ​ Work-life balance →​By looking at its parts, it could be seen that it came out from the ​ Formed by orbital gyri and straight gyri (gyrus rectus)[2027 Trans] olfactory nerve connections ​ Responsible for feelings of guilt (connections with →​More primitive parts are surrounded by more modern ones hypothalamus)[2027 Trans] enwrapped up by neocortex there ​ Receives information from sensory modalities (i.e. olfaction) ▪​ From inside to outside: Hippocampus, Entorhinal cortex, and through higher-order sensory cortical regions modern perirhinal cortex ○​ For integration of information for decision-making purposes[Martin, 2021] ​ Some people do not have this developed Figure 19. Parahippocampal cortex Figure 14. Orbitofrontal Cortex →​Entorhinal cortex PARAHIPPOCAMPAL GYRUS ▪​ Olfactory fibers are located here ▪​ Related to memory (why we associate smells with ​ Most medial portion of the temporal lobe memories) ​ Anterior and inferior continuation of the cingulate gyrus →​Rhinal sulcus ​ Contributes the uncus (most medial portion of the temporal lobe) ▪​ Where olfactory nerves descend into ○​ Can damage the brain stem[2026 Trans] →​Perirhinal cortex ○​ Hook of the Parahippocampal Gyrus ▪​ Houses the hippocampus ​ The cingulate gyrus actually a ring that has its own tract inside that is continuous with the parahippocampal gyrus and the white matter within is the cingulum ○​ Our decision making all now depends on what we will learn and remember from before Figure 20. Hippocampus (on top of the entorhinal cortex), Entorhinal cortex (orange), and perirhinal cortex (green) ​ Important in place recognition ○​ A brain tumor, electrical stimulation, or a seizure in this area can cause the feeling of déjà vu or the feeling that you’ve been somewhere before even if you haven’t ○​ Contains the parahippocampal place area ​ Inner map of the person’s world[2026 Trans] ​ Important in the encoding and recognition of scenes Figure 15 & 16. Lateral (above) and Inferior (below) views of the Parahippocampal ​ If the hippocampus is the video recorder, the Gyrus parahippocampal cortex is the tape (storage) ​ Complementary to the fusiform gyrus ​ Involved in facial recognition ​ Located in the lateral occipital temporal gyrus Figure 21. Parahippocampal place area (red) and fusiform gyrus (green) ​ Also involved in understanding the social context of situations →​Ability to grasp deep jokes →​Right PHC = recognizing sarcasm Figure 17 & 18. Diffusion tensor images showing the subdivisions of the cingulum bundle (colored) that are continuous with the PHC OS 202 Neuroanatomy of the Limbic System 3 of 8  HIPPOCAMPUS Function ​ Responsible for short-term memory ​ Plays a role in: ​ Hidden inside the parahippocampal cortex[2026 Trans] ○​ Memory ​ Appearance Functions as a personal autobiographical recorder ○​ Curled up edge of the medial temporal lobe cortex, resembles a Memory retrieval seahorse (sagittal view), a ram’s horn (coronal view), or a banana Starts with hippocampus before being pushed to (axial view superiorly) somewhere long term ○​ This is a gray matter that you don’t see in its totality because you No sleep → accumulation of toxic wastes which could only have cross-sections damage memory center[2026 Trans] It replays memories during sleep, which are then transferred to the neocortex Forgetting[2026 Trans] Different from not remembering Not remembering = not stored Forgetting = stored but deleted; intentional ○​ Spatial navigation ○​ Control of attention ​ Reciprocal relationship between memory and attention span i.e., “you cannot remember what you do not pay attention to” and vice versa[Trans 2027] FORNIX Figure 22. Hippocampus​ ​ Found at the anterior end of the hippocampus; divides into two pillars and ends at the septal nuclei and nucleus accumbens ​ Carries fibers from the hippocampus to the septal nuclei and the mammillary bodies →​Mammillary bodies ▪​ Vitamin B Deficiency due to malnutrition and alcoholism can destroy mammillary bodies −​ Alcoholics may become forgetful due to damage to the mammillary bodies →​Septal nuclei ▪​ Reward Center/Pleasure area of the brain ▪​ Reason why memory can be associated with motivation or rewards ▪​ If you want to remember something, you have to be motivated to remember it ​ Allows short-term memory stored in the hippocampus to be transmitted to other areas of the brain (store it, lose it, or use it) →​Enables short-term memory to travel to the cortex Figure 23. Hippocampus seen as a seahorse, ram’s horn, and banana ​ Innermost corner of cerebral cortex ​ Zone where the cortex narrows into a single layer of very densely Figure 25. Fornix packed neurons Structure and parts →​Only 3 layers thick in terms of histology →​The parahippocampal gyrus curls upon itself as the cerebrum, ​ The fornix as a whole is the “very long stalk” of a banana which and then narrows down and curls further as the hippocampus goes anteriorly. itself until we get to the very innermost called the dentate gyrus ​ Tract made of white matter ▪​ These areas are very sensitive to loss of oxygen ○​ Stops over at the mamillary bodies →​No granular neurons[2025 Trans] ○​ Another part continues to the septal nuclei and nucleus →​Layers decrease (6 > 5 > 4 > 3) as you move inwards accumbens, the pleasure areas of the brain →​Easily damaged by lack of oxygen, cardiac arrest, and seizures Alveus ▪​ Cardiac arrest for more than 12 minutes can lead to damage in the innermost parts ​ The origin of the fornix −​ Reason why memory loss occurs after near-death →​The fornix starts as a prominent white structure known as the experiences alveus ​ Hippocampus if it is a curly structure ​ Thin white layer on the ventricular surface of Ammon’s horn where →​Only look for it in the innermost part of the temporal lobe the fibers start to form →​If you can’t see it, you are either in the frontal pole or occipital →​Landmark: it is the floor of the temporal horn of the lateral pole ventricles ​ Fibers form the beginning of the fornix and then travels toward the Parts midline as a white matter tract ​ Summary →​PHC → extends to become the entorhinal cortex (ER) → curves in to form the straight subiculum (S) → curls again and forms the hippocampus proper (HP) → curls some more and forms the Innermost part, the dentate gyrus ​ Dentate gyrus →​Not to be confused with the dentate nucleus in the cerebellum →​Looks like an S or a seahorse →​Collection of gray matter in the innermost portion of the hippocampus Figure 26. The Alveus Remembering and Forgetting Remembering ​ In order to remember a certain thing, it must be stored in long-term memory. ​ The information passes through the fornix and travels to the temporal and frontal cortex. ​ Sleep →​“Sleep is your save button” Figure 24. Parts of the hippocampus[2028 Trans] →​The hippocampus replays memories during sleep, which are then transferred to the neocortex, thus saving them. OS 202 Neuroanatomy of the Limbic System 4 of 8  →​If you don’t sleep, part of the brain that is supposed to be saving information becomes damaged. ▪​ The less you sleep, the less you remember. ▪​ Your brain ages every time you pull an all-nighter due to production and accumulation of toxic waste or insoluble beta amyloid plaques[2027 Trans] ▪​ Young people can still recover from accumulation of toxic waste, but this ability decreases with age[2027 Trans] Forgetting ​ A conscious action or choice (intentional) ​ The temporal lobe and anterior cingulate cortex are activated ​ A way of compensating →​Why some people get PTSD (because they are unable to forget the traumatic experience)[2027 Trans] Figure 29. Stria terminalis REWARD CENTERS Insular cortex Amygdala ​ Intense feelings ​ Almond-shaped nucleus in the medial temporal lobe ○​ Associated with the intensity of liking (“love”) or disgust ○​ “Almond” in Latin ​ Appreciation of the taste of food ​ Anterior to the hippocampus ○​ Where most taste receptors signals terminate ○​ The structure for fear and anger is near the structure for ​ The anterior agranular component together with orbitofrontal memory. cortex for the anticipation of reward ○​ Rarely seen since it is small and hard to dissect[2026 Trans] ○​ Anterior agranular component initiates the ‘liking’ ​ Composed of gray matter only, with no curling of gyri ○​ “What‘s in it for me?” ​ Functions PUTAmen (Putamen) ○​ Processing and memory of emotional reactions (mainly fear and anger) and smell ​ Implicated in the “hate circuit” ○​ Phobia[2027 Trans] ○​ Hate is a choice = superior frontal gyrus ○​ Psychopathic states ○​ Intensity of hate = insula ○​ Binge-drinking[2027 Trans] ○​ Execute the hate = putamen ​ Over-activation may cause extreme fear or anger, psychosis, phobias, binge-drinking ​ Has connections to the hypothalamus ○​ Anger or fear manifests physically through changes in blood pressure, heart rate, and respiratory rate because of this ○​ Very closely related to the hippocampus ​ This is why certain people, places, or things can trigger memories and unpleasant emotions Figure 30. Putamen in the hate circuit ​ Intensity of hate depends on state of mind ​ Also part of the romantic passion circuit →​Connections with the insular cortex and globus pallidus Caudate nucleus ​ Falling in love and attraction ​ Appreciation for beauty Figure 27. Position of the amygdala relative to the hippocampus ​ Intense romantic passion Stria Terminalis ​ Trunk/connector of amygdala ​ Thin strip of white matter ​ Found near midline, above the hypothalamus, in the walls of the third ventricle, together with the thalamus ​ Major outflow tract of amygdala ​ Connects the amygdala with the hypothalamus, anterior commissure, preoptic area, and septal region ○​ How fear and anger manifests ○​ Affect heartbeat, influence lungs, respiratory muscles, deactivates “happy places” in the brain[2027 Trans] ​ Functions ○​ Modulation of memory Figure 31. Caudate nucleus (where emoji is situated)[2027 Trans] ○​ Emotional responses → its main function ○​ Modulation of pain Claustrum ○​ Sexual behavior ​ One neuron to rule them all (still needs more study) ○​ Sexual identity ○​ Every part of the brain has axon from the caudate nucleus ​ Gray matter between insular cortex and putamen ○​ Separated from the putamen by the external capsule ○​ Separated from the insular cortex by the extreme capsule Figure 28. Position of the stria terminalis Figure 32. Position of the claustrum and insula OS 202 Neuroanatomy of the Limbic System 5 of 8  Ventral tegmental area ​ Neurons contain dopamine ○​ Dopamine = ‘fuel’ that powers the limbic system ○​ Provides dopaminergic innervation to the frontal cortex and limbic system (septal nuclei and nucleus accumbens) ​ Activities that elicit pleasure activate this area, including psychostimulants like cocaine and ecstasy. ​ Reward / addiction ○​ For motivation Figure 33. Claustrum and boundaries ○​ Stimulation = enjoyable ​ If inhibited, leads to avoidance behavior/ fear ​ Also activated in romantic love ​ Motivation, reward, obsession, intense love is via insula and amygdala ○​ Emotional stability and rationality requires balance in the functions of insula and amygdala Figure 34. Position of claustrum and putamen ​ Function is not yet fully known →​Seat of visual consciousness Figure 38. Ventral tegmental area →​Cortical satellite (part of cerebral cortex) →​Role for corticoclaustral circuits in directing attention and Medial forebrain bundle maintaining vigilance (alertness) ​ Connects the VTA to the prefrontal cortex and nucleus accumbens ​ Neurons extend throughout the brain. ​ Passes through the anterior limb of the internal capsule →​Dense connections to frontal lobe and anterior cingulate cortex ​ How the dopamine is delivered to the septal nuclei and nucleus →​Modest connections to the temporal, parietal, and occipital lobes accumbens (sensory cortices) ​ Pathway of dopamine: medial forebrain bundle from midbrain → anterior limb of internal capsules → midline → frontal lobes → reward centers (septal nuclei and nucleus accumbens) ​ Deep brain stimulation where an electrode for Parkinson’s disease is implanted in the subthalamic nucleus ○​ Medial forebrain bundle is medial to the subthalamic nucleus ○​ If implant is too near the medial forebrain bundle, the patient may get acute hypomania ​ Displays a revved up energy or activity level, mood, or behavior ​ Pathologic excited state, “new energized you” ​ Part of bipolar disorder Figure 35. Claustrum neural connections Septal nuclei ​ Pleasure zone Figure 39. Medial forebrain bundle (MFB) II.​ BASIC INSTINCTS A.​ VENTRAL TEGMENTAL AREA (VTA) AND EATING ​ Ghrelin ○​ A hormone secreted by stomach to signal hunger ○​ Stimulates food intake Figure 36. Septal nuclei ○​ Promotes weight gain Nucleus accumbens ○​ Plays a role in glucose metabolism ​ Ventral Tegmental Area ​ Part of corpus striatum ○​ Has receptors for Ghrelin ​ Placebo effect ○​ Sensitive to feeling of hunger ​ Addiction (drugs, gaming) ○​ Overeating disorders ○​ Loss of control ​ Results from overproduction of dopamine from VTA due to ​ Gets dopamine from the ventral tegmental area constant stimulation of Ghrelin ○​ Overactivity → Obesity HOW GHRELIN REACHES THE HYPOTHALAMUS AND VTA ​ Median eminence ○​ Part of the hypothalamus near the third ventricle ○​ Has fenestrated capillaries, allowing ghrelin to reach CNS from circulation since it cannot cross the BBB Figure 37. Nucleus accumbens Figure 40. Location of median eminence OS 202 Neuroanatomy of the Limbic System 6 of 8  ACTIONS OF GHRELIN IN THE HYPOTHALAMUS ​ Stomach → Ghrelin → Circulation → Median eminence → Hypothalamus → VTA ​ Ghrelin acts on Growth Hormone secretagogue receptors in hypothalamus ​ Hypothalamic nuclei involved in increasing appetite are: ○​ Arcuate nucleus ​ Promotes eating ​ Increases weight gain ​ Feeling hungry and wanting to eat ○​ Ventromedial nucleus ​ Triggers food intake Figure 43. Locations of Olfactory tubercle (left) and Nucleus accumbens (right) ​ Commands the body to stand up, go out, look for food, and eat ○​ Lateral hypothalamus WHAT MAKES THE BRAIN “LIKE” FOOD? ​ 2 neuron populations ​Melanin concentrating hormone (MCH) ​ “Liking” food answers the following parameters: ​Orexins (hypocretins) ○​ Is it palatable? ​ MCH and Orexins neurons targets: ○​ Is it sweet? ​Trigeminal, Facial and Hypoglossal motor nuclei to lick, chew ○​ Does it bring back pleasant memories? and swallow the food: III.​ AREAS OF THE BRAIN THAT LIKE FOOD ​Parasympathetic preganglionic nuclei in the medulla for salivation, gut motility, and gut secretions A.​ CEREBRAL CORTEX ​ Even if your stomach is full, there will be space for food because appetite overrides the feeling of fullness. ORBITOFRONTAL CORTEX ○​ Addiction to food also involves the eyes (phenomenon known as ​ Responsible for the conscious choice that makes a person want takaw-mata) to eat even if full[2026 Trans] ​ Ghrelin activates VTA → VTA releases dopamine destined for ​ “To eat again” is a choice nucleus accumbens ○​ Net effect: You want to eat more ​ Nucleus accumbens ○​ Triggers the action of wanting to eat more and more (e.g. during buffets and unlimited rice promotions) Figure 44. Orbitofrontal Cortex (Green) ANTERIOR CINGULATE CORTEX ​ Decision making ​ I don’t care if I'm gonna get fat or I’ll get diabetes or hypertension, basta masarap siya eh! ​ Is it right or wrong to go back for more? (e.g. buffet)[2026 Trans] Figure 41. (a) Reward and (b) homeostatic pathways of food in the brain NEURAL CONTROL OF WANTING VS LIKING FOOD ​ VTA + Nucleus Accumbens = Activation of Reward center ○​ Motivation ○​ “I want to eat this because I find it rewarding to eat it” ​ Activation of Pleasure center ○​ “I like this food because it tastes so good” ○​ Brings back memories of wanting to feel good again and again ○​ Function of the amygdala WHAT MAKES THE BRAIN “WANT” FOOD? ​ Sweet or oily food ○​ Stimulates a rewarding feeling ​ Food can be rewarding, even addictive if it increases the dopamine in the Ventral striatum ​ Ventral striatum Figure 45. Anterior Cingulate Cortex[Pascual, 2025] ○​ located near the putamen and caudate nucleus, part of the basal ganglia ○​ Composed of: ​ Nucleus accumbens ​Motivation to do things over and over again ​Base of corpus striatum[2026 Trans] ​Responsible for eating[2026 Trans] ​Connects to the more primitive olfactory tubercle where the olfactory nerves penetrate the brain[2026 Trans] ​ Olfactory tubercle Figure 46. Anterior Cingulate Cortex INSULAR CORTEX ​ Also called The Isle/Island of Reil ​ For cravings ​ Responsible for intense liking for certain tastes[2026 Trans] ​ Mainly gustatory[2025 Trans] → Just thinking about food makes you salivate. Figure 42. Location of Ventral striatum (VS) OS 202 Neuroanatomy of the Limbic System 7 of 8  AMYGDALA ​ The feeling of loving to eat i.e., emotional attachment ○​ This makes it easier to memorize and desirable Figure 47. Insular cortex (red) B. SUBCORTICAL GRAY MATTER (BASAL GANGLIA) ​ Automatic circuit[2025 Trans] ​ Tells you when to stop or not to stop[2026 Trans] NUCLEUS ACCUMBENS ​ Compulsion to eat[2023 Trans] Figure 51. Amygdala ​ Hedonic hotspots for liking or wanting food[2025 Trans] LATERAL HYPOTHALAMUS → Similar areas activated by marijuana ​ Effector component → Not simply liking the food but wanting it ​ Nuclei of the hypothalamus ▪ If you like food, you will want it ○​ For appetite Figure 48. Nucleus accumbens (blue) and globus pallidus (red) Figure 52. Lateral hypothalamus (in blue box) C. BRAINSTEM PARABRACHIAL NUCLEUS ​ For appreciation of what you eat ○​ For approval ○​ You can eat this kasi masarap siya after matikman ○​ Leads you to motivate yourself because the past was good ​ Final common pathway[2027 Trans] ○​ Once a person puts food in the mouth and eats it ​ Mediates deliciousness of food[2026 Trans] ○​ Area responsible for making a person enjoy if food is delicious ○​ Helps the person decide if they will eat again[2026 Trans] Figure 49. Hedonic hotspots for liking food (left) and wanting food (right) in the nucleus accumbens of mice VENTRAL PALLIDUM ​ Ventral area of the globus pallidus[2028 Trans] ​ Recently discovered center for liking sensory pleasure ​ Mediates liking for sweet, salty, or other food rewards Figure 53. Parabrachial nucleus (in red circle) Figure 50. Opioid “Liking” and “Wanting Zones” in the Ventral Pallidum IV.​ REFERENCES Koo, M. S., Levitt, J. J., Salisbury, D. F., Nakamura, M., Shenton, M. E., & McCarley, R. W. N. ACCUMBENS AND VENTRAL PALLIDUM (2008). A cross-sectional and longitudinal magnetic resonance imaging study of cingulate gyrus gray matter volume abnormalities in first-episode schizophrenia and ​ Mediate liking via first-episode affective psychosis. Archives of general psychiatry, 65(7), 746–760. ○​ Opioids - enkephalins and endorphins https://doi.org/10.1001/archpsyc.65.7.746 ○​ Endocannabinoids - anandamide Pascual, J.L. (2025). Neuroanatomy of the Limbic System. ​ Marijuana is recognized as anandamide in the brain Martin, D. (2021). Neuroanatomy: Text and Atlas (5th ed). New York: McGraw Hill ​ Same potency as when taking marijuana UPCM 2028 Trans. (February 5, 2024). Neuroanatomy of the Limbic System. ​ Final common pathway for both drugs and food while eating[2026 Trans] ​ The most exploited since 2016 OS 202 Neuroanatomy of the Limbic System 8 of 8