Neuroanatomy

Amygdala  A collection of smaller nuclei in the medial temporal lobe, it plays a central role in the emotional aspects of memory, decision-making, and emotional reactions including fear conditioning.

Hippocampus - plays a critical role in semantic memory formation and in spatial navigation, which is mental mapping, like remembering routes on autopilot.

Thalamus - relays sensory and motor signals between the cerebral cortex and subcortical structures. Thought to play an important role in regulation of consciousness, alertness, and sleep

Habenula - functions as the Eeyore from Winnie the Pooh, meaning any time there is an unexpected setback or absence of an expected reward, it activates to dampen dopamine and serotonin firing, pessimistically predicting disappointment and misfortune.

Hypothalamus - regulates endocrine, autonomic, and behavioral functions, including:

- Pituitary hormones

- Temperature regulation

- Control of water and food intake

- Sexual behavior and reproduction

- Mediation of emotional responses

Pituitary - a gland at the bottom of the hypothalamus. Anterior lobe secretes all of the releasing hormones you typically think of. Posterior lobe handles oxytocin and ADH (aka vasopressin).

- Raphae nuclei - predominant serotonin projections

- Periaqueductal gray - functions in pain inhibition. Also involved in freeze responses in animals.

- Locus ceruleus is the primary site for noradrenergic cell bodies, like norepinephrine. Important in arousal and sleep-wake cycles.

- Ventral tegmental area houses dopaminergic production. Also the origin of the mesolimbic and mesocortical dopamine pathways. Important in reward, motivation, salience attribution, cognition, and conditioned learning. Highly relevant for addiction, mood disorders, and schizophrenia.

The nucleus basalis of Meynert is a cholinergic nucleus. Acetylcholine activity promotes wakefulness, REM sleep, and enhances attention and memory.

The striatum is comprised of the caudate, putamen, and nucleus accumbens, and it is critical in procedural learning and habit formation.

The nucleus accumbens is centrally important in reward processing, motivation, and decision making, and is highly relevant in mood disorders and addiction.

Subthalamic nucleus lesions are associated with choreiform movements and contralateral ballism. It's a target for surgical lesions and DBS, and it can improve Parkinson's symptoms.

Anterior cingulate cortex plays an important role in detecting conflicts and errors and evaluating the appropriateness of potential alternative responses via reward-based learning theory. Also important in decision-making, impulse control, motivation, and social evaluation.

The subgenual anterior cingulate cortex is targeted by some DBS studies in refractory depression.

Posterior cingulate/Isthmus - is active during internally directed attention, part of the default mode network

- Prefrontal cortex comprises most of the frontal lobes, associated with executive functioning, decision-making, planning outcomes, moderating social behavior, and regulating emotion and impulses.

- Orbitofrontal cortex is implicated in evaluating reward versus punishment contingencies. It is impaired in people with sociopathy and addiction disorders.

- The dorsal lateral prefrontal cortex is involved in various higher cognitive functions, including working memory, set shifting, cognitive flexibility, decision-making, planning, inhibition, abstract reasoning, and free will. It's part of the prefrontal cortex.

- The ventrolateral prefrontal cortex is important in mediating attention control, suppressing attention towards distraction. Activity here is increased in depression, and activation is associated with vigilance and anxiety states.

The insula has connections with the amygdala and other connections that lead to somatosensory sensations or somatization. It's critical to the process of interoception, which is important to various concepts such as empathy, sense of bodily self-awareness and agency, visceral pain processing, and emotional regulation.

Temporal pole lesions are associated with diminished fear, hyperorality, hypersexuality, blunted affect, and social withdrawal.

Fusiform gyrus is involved in processing color, face and body recognition, and word recognition. It is involved in neurological phenomena such as synesthesia and dyslexia when it has abnormalities.

Lingual dyspraxia is associated with complex visual images, facial processing, and attributing intentions of others.