Brain Regions/Functions – Hindbrain, Midbrain, and Subcortical Forebrain Structures

brainstem damage

symptoms may include respiratory problems, difficulty swallowing, slurred speech, problems with balance and coordination, nausea, sleep disturbances, confusion, or loss of consciousness

forebrain structures

subcortical (hypothalamus, thalamus, basal ganglia, amygdala, cingulate cortex, hippocampus) and cerebral cortex

hindbrain structures

medulla, pons, cerebellum

medulla

involuntary mouth and throat movements involved in swallowing, couching, and sneezing. regulates respiration, heart rate, blood pressure. brain injury/certain diseases and drugs (especially opioids) disrupt function here

pons

connects two halves of the cerebellum and helps coordinate movements on two sides of body. relays messages between the cerebellum and cerebral cortex. also, respiration, deep sleep regulation, and REM

cerebellum

coordinates voluntary movements and is responsible for maintaining posture and balance. damage causes ataxia, impaired balance and coordination, slurred speech, nystagmus, and blurred or double vision. important for processing and storing procedural memories and other implicit memories. involvement in attention, linguistic processing, and visuospatial abilities

midbrain structures

reticular formation and substantia nigra

reticular formation

network of neurons extending from medulla into midbrain. functions include muscle tone, coordination of eye movements, and control of pain. contains the RAS, which mediates consciousness and arousal, controls the sleep/wake cycle, and alerts cerebral cortex to incoming sensory signals. lesions can cause coma, while direct stimulation awakens

substantia nigra

reward-seeking, drug addiction, and through connections with the basal ganglia, motor control. degeneration of dopamine-producing cells causes slowed movement, tremors, rigidity, and other motor symptoms associated with PD

subcortical forebrain structures

hypothalamus, thalamus, basal ganglia, amygdala, and hippocampus

hypothalamus

maintains homeostasis, regulates autonomic nervous system and pituitary gland. regulates body temperature, blood pressure, heart and respiration rates, thirst and hunger, growth, sexual activity, reproduction, and body’s response to stress. contributes to emotions, memory, and circadian rhythms.

damage to hypothalamus

aggressive behavior, rage, crying, laughter

mammillary bodies

within the hypothalamus, role in memory

suprachiasmatic nucleus (SCN)

within the hypothalamus, biological clock and regulates sleep-wake cycle/circadian rhythms

hypothalamus effect on anterior pituitary

initiates development of secondary sex characteristics, regulates maturation and maintenance of reproductive system by secreting gonadotropin-releasing hormone, which leads this to secrete gonadotropins that regulate the functions of the testes and ovaries

hypothalamus effect on posterior pituitary

sends vasopressin and oxytocin; oxytocin is sent during childbirth and lactation, while vasopressin regulates water balance

oxytocin/vasopressin

role in social bonding, trust, emotion recognition, social memory, sexual behaviors, aggression, fear, anxiety, stress

oxytocin & mental health disorders

beneficial effects for ASD, schizophrenia, and other social-emotional cognition. intranasal use in ASD improves emotion recognition. high levels in healthy adults has adverse effects; high levels impaired ability to accurately identify facial expressions

thalamus

relay station, receives and transmits sensory information to cortex for all senses but smell. role in sensory/motor functioning, language and speech, and declarative memory.

korsakoff syndrome

caused by thiamine deficiency often resulting from chronic alcoholism. damages neurons in thalamus and mammillary bodies, resulting in anterograde amnesia, retrograde amnesia, and confabulation

basal ganglia

caudate nucleus, putamen, nucleus accumbens, and globus pallidus.

striatum

caudate nucleus, putamen, and nucleus accumbens

basal ganglia function

initiation and control of voluntary movements, procedural and habit learning, cognitive functioning, and emotions

basal ganglia damage

linked to mood disorders, schizophrenia, ADHD, OCD< Tourette’s, Huntington’s, and PD.

limbic system

amygdala, cingulate cortex, and hippocampus. involved in emotion, motivation, and memory.

amygdala

fear, anger, anxiety, joy, and other emotions, attaching emotions to memories, emotional responses to pain, willingness to take risks, mediating aggressive behaviors. key role in pain modulation.

Kluver-Bucy syndrome

bilateral lesioning of the amygdala, hippocampus, and temporal lobes in rhesus monkeys produced a syndrome which includes hyperphagia, hyperorality, reduced fear, hypersexuality, and visual agnosia

cingulate cortex

motivation, memory, and emotions, including emotional reactions to pain. people with damage here experience pain but are not distressed by it. abnormalities linked to MDD.

hippocampus

memory, transferring declarative memories from short-term to long-term, spatial memory. degeneration linked to AD. acute/chronic increases in cortisol levels in the hippocampus impairs retriveal of declarative memories.