Week 3: Macro Neuroanatomy

Sub-cortical brain regions

below the cortex

• hindbrain, midbrain, forebrain

Hindbrain

• medulla oblongata

• pons

• reticular formation

• cerebellum

Medulla

• top of spine

• critical life functions - damage is life threatening

• several sensory and motor pathways

Pons

• on top of medulla

• regulation of REM

• several pathways that sends info from face, eyes, ears to the brain

• neurons connect with contralateral side/crossover

Reticular Formation

• deep within medulla and pons

• regulates attention, arousal, wakefulness and sleep

• damage - comatose or death

• acts as a bridge between PNS and CNS

Cerebellum

• bottom of the brain

• many deep folds

• coordinate motor control and smooth motor movements unconsciously

• cerebellum hypoplasia - underdeveloped

Midbrain

keeps us alive and works unconsciously

• superior collicus

• inferior collicus

• substantia nigara

• tectum & tegmentum

superior collicus

vision and eye movements

inferior collicus

hearing

substantia nigara

movement, reward, motor control

Forebrain

evolved more recently

• Thalamus

• Hypothalamus

• Basal Ganglia

• Hippocampus

• Amygdala

thalamus

• centre of brain - chamber for each hemisphere

• sensory relay station

• spatial learning and memory

hypothalamus

• motivation - approach and avoidance behaviours

• regulates fighting, fleeing, feeding, fornicating

• lesioning influences eating

Basal Ganglia

• deep in brain, beside thalamus, extending to hindbrain

• movement, memory, emotional regulation

• smoothed, planned, coordinated muscle movemtns

• damage - parkinson’s disease

Nucleaus accumbens

• part of basal ganglia

• reward seeking behaviours

hippocampus

• forming and storing memories

• connections to cerebral cortex and amygdala

• spatial learning and memory

• damage —> antegrade amnesia (case of H.M)

Amygdala

• emotions, relevence detector, social info, memory and learning

• damage —> S.M - no fear

Studying the brain

• brain damage

• psychosurgery

• neuroimaging

• brain stimulation

brain damage

limitations: uncontrolled, diffuse damage, rare, difficult to compare, invasive

psychosurgery

surgical interventions on the brain to treat mental disorders by severing connections between brain areas or stimulating areas

limitations: highly invasive and dangerous, non-reversible

neuroimaging

images of the structure and function of the brain

• EEG - detects, amplifies, records electrical activity in the brain —> non-invasive, good temporal resolution, poor spatial resolution

• MRI - structure and produces detailed images of almost every internal structure, non-invasive, poor temporal resolution, good spatial resolution

• fMRI - structure and measure tiny changes in blood flow, non-invasive, poor temporal resolution, good spatial resolution

• PET - function and use of radioactive substance, invasive, poor temporal resolution, good spatial resolution

brain stimulation

limitations: invasive vs non-invasive, seizure risk, inter-individual variablity

limitations of a nuerobiological approach

• conflating description with explanation

• brain imaging links to phrenology

• brain regions do not act alone