Thalamus

Purpose of the thalamus is

transmit information in relevant packages to avoid bombarding with unprocessed redundant information

Only sensory modality that doesn’t reach thalamus

olfaction (goes straight to bulb)

Somatosensory and Visual nuclei are found where

in the ventral region of the thalamus

Limbic nuclei are found where

in the anterior and lateral dorsal region of the thalamus

Multimodal nuclei are found

in the posteior, medial dorsal, and intralaminar portion of the thalamus

Dorsal Medial Portion

input from prefrontal cortex, output to the prefrontal cortex and limbic system

function: decision making/judgement

Intralaminar Portion

input from reticular formation(rostral), output to cerebral cortex

function: arousal

Posterior/ Lateral posteior portion

input from cerebral cortex, output to cerebral cortex

function: attention

Posterior Ventral (VPL)

input from dorsal column /spinothalamic system, output to somatosensory cortex

function: somatosensory neck down

Posterior Ventral (VPM)

input from the trigeminal system, output to somatosensory cortex

function: somatosensory head

Medial Geniculate

input from inferior colliculus, output auditory cortex

function: hearing

Lateral Geniculate

input from retina, output to visual cortices

function: vision

VL/VA

input from cerebellum, output motor cortices

VA/VL

input basal ganglia, output motor cortices

function: motor planning

Anterior / Lateral Dorsal Portion

input from hypothalamus, amygdala, and hippocampus, output limbic lobule

function: memory / emotion

Intrathalamic (reticular) nucleus

input from cortex/brainstem, output to thalamus

function: (inhibitory), thalamic modulation

Blood supply to thalamus comes from

MCA/PCA

Dejerine-Roussy Syndrome

stroke in ventral portion of thalamus, main symptom excessive pain from stimuli on contralateral side

treatment: opiates, rehabilitation

Korsakoff’s Syndrome

damage to anterior portion of nucleus, caused by lack of Thiamine (B1)

emotional and memory effects (apathy/confabulation)