cortical structures

Amygdala - structure

It is composed of distinct nuclei: central, medial, cortical, lateral, basomedial, and basolateral. These regions interact with the hippocampus and cortex to form key circuits for emotion and memory processing.

Cingulate Cortex - structure

It includes anterior, middle, posterior, and retrosplenial regions. These areas curve around the corpus callosum and link limbic, prefrontal, and parietal regions, integrating emotion, attention, and memory signals.

Hippocampus - structure

It forms an elongated, curved structure in the medial temporal lobe and includes the dentate gyrus, CA1–CA4 subfields, and subiculum. Connected to the fornix, it links with the thalamus and cortex.

Insula - function

It integrates interoceptive signals with emotion and cognition. The anterior part processes feelings like empathy, disgust, and craving, while the posterior region maps internal bodily states like pain and heartbeat.

Hypothalamus

Maintains homeostasis (e.g., hunger, temperature, sleep) Drives instinctual behaviors Controls ANS and pituitary gland (hormones)

Thalamus

Relays sensory input to cortex (except smell) Regulates attention and alertness Coordinates signals between brain regions

Pituitary Gland

Releases hormones for growth, stress, reproduction Controlled by the hypothalamus Connects nervous and endocrine systems

Mammillary Bodies

Part of the memory circuit (Papez circuit) Important for recalling memories Damage causes amnesia

limbic lobe (structure)

A.S.H.A.D. O amygdala, septal nuclei, hypothalamus, anterior nuclei of the thalamus, dorsomedial nuclei of the thalamus, olfactory bulb

limbic lobe (function)

5Fs - feeding (satiety and hunger), forgetting (memory), fighting (emotional response), family (sexual reproduction, maternal instincts), fornicating (sexual arousal)

Septal Nuclei

Involved in reward, pleasure, and reinforcement Regulates emotional bonding and social behaviors Modulates aggression and connects with the hippocampus and hypothalamus

Olfactory Bulb

Processes smell (olfactory information) Directly linked to amygdala and hippocampus Explains why smells strongly trigger memories and emotions

fornix

Connects the hippocampus to the hypothalamus, especially the mammillary bodies Key role in the memory circuit (Papez circuit) Essential for recalling long-term declarative memories Damage can lead to anterograde amnesia

Medulla oblongata

Located at the base of the brainstem, connects the brain to the spinal cord. Controls automatic functions e.g. breathing, heart rate, and blood pressure. Manages reflexes like coughing, sneezing, swallowing, and vomiting.

Pons

Located in the brainstem, connects the medulla oblongata to the midbrain. It plays a key role in relaying signals between the cerebrum and cerebellum, especially for motor control. Regulates sleep, respiration, and facial sensations and movements.

Putamen

Part of the basal ganglia, working closely with the caudate nucleus. Involved in regulating voluntary motor movements and procedural learning. Helps control habit formation and reinforcement learning.

Globus Pallidus

Part of the basal ganglia. Essential for inhibiting excessive movement by regulating thalamic and cortical activity. Dysfunction linked to movement disorders like Parkinson’s disease.

Caudate Nucleus

wraps around the thalamus and works closely with the putamen. Important for motor control, goal-directed actions, and learning from feedback. Contributes to cognitive functions like memory and attention.

Nucleus Accumbens

Part of the basal forebrain, a key component of the brain’s reward circuit. Processes reward, pleasure, motivation, and reinforcement learning. Plays a major role in addiction, linking dopamine release to rewarding stimuli.

Substantia Innominata

Part of the basal forebrain Contains a mix of neurons, including cholinergic, GABAergic, and glutamatergic cells, and connects to other cortical areas. Plays a role in attention, arousal, and learning, supporting cortical activity and memory processing.

Basal Nucleus of Meynert

The main cholinergic output of the basal forebrain, sending acetylcholine projections to the cerebral cortex. Critical for attention, learning, memory, and cortical plasticity. Degeneration strongly linked to Alzheimer’s disease and cognitive decline.

Corpus callosum - structure

A thick white matter band connecting left and right hemispheres. Divided into rostrum, genu, body, and splenium, it arches above the ventricles and links corresponding cortical areas across both sides.

Corpus callosum - function

Enables interhemispheric communication for sensory, motor, and cognitive tasks. Supports coordination, unified perception, and complex thinking by integrating input from both sides of the brain.

Corpus callosum - damage

Damage or absence causes hemispheric disconnection. May result in split-brain syndrome, motor or language deficits, or impaired reasoning, depending on which part is affected and the person’s development.

Amygdala - function

Processes emotions, especially fear and threat detection. It links sensory input to emotional responses and helps form emotional memories, playing a central role in survival, learning, and social behavior.

Amygdala - dysfunction

Damage or dysfunction may cause blunted or exaggerated emotional responses, especially fear. Linked to anxiety, PTSD, phobias, and in rare cases, emotional flatness as seen in Urbach–Wiethe disease

Cingulate cortex - function

It integrates emotion, attention, and bodily states to guide behavior. The anterior part handles error detection and decision-making, while the posterior regions are involved in memory, spatial orientation, and self-awareness.

Cingulate cortex - dysfunction

Damage can cause apathy, poor emotional regulation, impaired attention, and memory issues. In some cases, it contributes to depression, OCD, chronic pain, and difficulties in adapting behavior after errors or conflict.

Insula - structure

It lies deep within the lateral sulcus, hidden beneath the frontal, temporal, and parietal opercula. Divided into anterior and posterior regions, it connects to limbic, somatosensory, and autonomic networks.

Insula - dysfunction

Disruption may impair self-awareness, emotional experience, and body-state regulation. Linked to anxiety, addiction, eating disorders, and alexithymia—difficulty identifying and expressing emotions.

hippocampus - function

It encodes and consolidates new declarative memories and supports spatial navigation. Crucial for distinguishing similar experiences, it also integrates context with emotion via connections to the limbic system.

Hippocampus - dysfunction

Damage causes anterograde amnesia—difficulty forming new memories. Early degeneration is seen in Alzheimer’s disease, and dysfunction contributes to disorientation, poor recall, and impaired spatial awareness.