Thalamus

thalamus

integrate/relay sensory info; integrate/relay motor info from cerebellum and basal ganglia to motor cortex

thalamus

gates passage of sensory/motor info

thalamus

transmit state of consciousness from brainstem to cortex

relay, interlaminar, reticular

main categories of thalamic nuclei

specific relay nuclei

projections to primary sensory and motor areas

specific relay nuclei

are located mainly in lat thalamus

VPL/M, L/MGN, VL, ant nucleus

specific relay nuclei

pulvinar, MD

widely projecting (nonspecific) relay nuclei

interlaminar nuclei

lies w/in internal medullary lamina

interlaminar nuclei

main inputs and outputs w/ basal ganglia

reticular nucleus

thin sheet lat to thalamus and medial to internal capsule

reticular nucleus

doesn’t project to cortex; inputs and outputs are w/in thalamus

VPL

input: medial lemniscus, spinothalamic tract

VPL

output: somatosensory cortex

ventral post lat nucleus (VPL)

relays somatosensory spinal inputs to cortex

VPM

input: trigeminal lemniscus, trigeminothalamic tract, taste

VPM

output: somatosensory and taste cortex

ventral posteromedial nucleus (VPM)

relays somatosensory CN inputs and taste to cortex

LGN

input: retina

LGN

output: primary visual cortex

lat geniculate nucleus (LGN)

relays visual inputs to cortex

MGN

input: inf colliculus

MGN

output: primary auditory cortex

medial geniculate nucleus (MGN)

relay auditory inputs to cortex

VL and VA

input: internal globus pallidus, deep cerebellar nuclei, substantia nigra pars reticulata

VL

output: motor, premotor, supplementary motor cortex

ventral lat (VL) and ventral ant nucleus (VA)

relays basal ganglia and cerebellar inputs to cortex

VA

output: widespread to frontal lobe (prefrontal, premotor, motor, supplementary motor cortex)

pulvinar

input: tectum (extrageniculate visual pathway), other sensory inputs

pulvinar

output: parietotemporooccipital association

pulvinar and lat post nucleus

behavior orientation towards relevant visual and other stim

lat dorsal nucleus

functions w/ ant nuclei

lat post nucleus

functions w/ pulvinar

VMN

input: midbrain reticular formation

VMN

output: widespread to cortex

ventral medial nucleus

may help maintain alert, conscious state

mediodorsal nucleus (MD)

medial nuclear grp

MD

input: amygdala, olfactory cortex, limbic basal ganglia

MD

output: frontal cortex

mediodorsal nucleus (MD)

limbic pathways, major relay to frontal cortex

ant nucleus and lat dorsal nucleus; midline thalamic nuclei

limbic pathways

ant nucleus

input: mammillary body, hippocampal formation

ant nucleus

output: cingulate gyrus

midline thalamic nuclei

input: hypothalamus, basal forebrain, amygdala, hippocampus

midline thalamic nuclei

output: amygdala, hippocampus, limbic cortex

rostral intralaminar nuclei

parts: central medial/lat nucleus, paracentral nucleus

rostral intralaminar nuclei

input: deep cerebellar nuclei, globus pallidus, brainstem ascending reticular activating systems (ARAS), sensory pathways

rostral/caudal intralaminar nuclei

output: cerebral cortex, striatum

rostral intralaminar nuclei

maintain alert consciousness; motor relay for basal ganglia and cerebellum

caudal intralaminar nuclei

parts: centromedian nucleus, parafascicular nucleus

caudal intralaminar nuclei

input: globus pallidus, ARAS, sensory pathways

caudal intralaminar nuclei

motor relay for basal ganglia

reticular nucleus

input: cerebral cortex, thalamic relay, intralaminar nuclei, ARAS

reticular nucleus

output: thalamic relay and intralaminar nuclei, ARAS

reticular nucleus

regulates state of other thalamic nuclei