diencephalon

thalamus function

• relay station

• gateway to cerebrum

thalamus input

• spinal cord

• brainstem

• basal ganglia

• cerebellum

what borders the thalamus

• third ventricle (medial)

• internal capsule (lateral)

• lateral ventricles and fornix (superior)

how is internal medullary lamina divided

1. anterior group

2. medial group

3. lateral group

anterior nuclei recieves input frum

• mammillary bodies

  • hippocampus

sends info: anterior nuclei

cingulate gyrus

concerned with: anterior nuclei

memory and emotion (limbic activities)

*one of the first neuroanatomical circuits found to be associated w memory and emotion

receives info: dorsal medial

• olfactory (doesnt stop here, it just goes through)

• limbic structures

sends info: dorsal medial

prefrontal cortex (phineas gage)

concerned with: dorsal medial

• affect

• social interactions

• memory

• limbic activities

Korsakoff → cant form new memories

Affective Disorders → Phineas Gage; become a bad person

receives input: ventral anterior and ventral lateral

• basal ganglia

• cerebellum

send info: ventral anterior and ventral lateral

• ipsilateral motor cortex (precentral gyrus)

concerned with: ventral anterior and ventral lateral

voluntary motor activitoes

recieves info: Ventral posterior nuclei (VPM, VPL)

• face VPM

• body VPL

sends info: Ventral posterior nuclei (VPM, VPL)

• face VPM

• body VPL

injury = impaired sensation contralaterally (Dejerine-Roussy)

concerned with: Ventral posterior nuclei (VPM, VPL)

somatosensory (postcentral gyrus)

does olfactory pass through the thalamus

no

LGN lateral geniculate nucleus recieves

retina

sends info: LGN lateral geniculate nucleus

primary visual cortex

LGN lateral geniculate nucleus concerned with

visual relay

recevies info: Medial geniculate nucleus

inferior colliculus (auditory structure)

sends info: Medial geniculate nucleus

primary auditory cortex (temporal lobe)

concerned with: Medial geniculate nucleus

auditory relay

recieves input: pulvinar nucleus

• temporal, parietal, occipital ‘association’ cortex

• - visual system (superior colliculus)

sends info: pulvinar nucleus

• Ipsilateral “association” cortex

• projections back to primary visual cortex

concerned with: pulvinar nucleus

• visual perception (ex. make sense of what ur seeing “this is a desk” rather than just wood)

• language (damage can result in aphasic syndromes, like that resulting from cortical damage

thalamic disorders can cause…

• sensory loss

• abnormalities in affect (inappropriate social behavior)

• memory deficits

• Fatal Insomnia

• Coma

hypothalamus maintains…

homeostasis

recieves info: hypothalamus

• widespread areas in CNS

• limbic structures/forebrain (e.g. hippocampus via fornix)

• brainstem

• spinal cord

sends info: hypothalamus

• reciprocal projections to major input areas

• pituitary

Hypothalamus: Suprachiasmatic nucleus

• biological clock

• circadian rhythms

• input from the retina can set the intrinsic clock

Hypothalamus: Preoptic nucleus

• Gonadotrophic (reproductive) hormone release

Hypothalamus: Paraventricular and supraoptic nuclei

• direct release to the bloodstream

• vasopressin (ADH) - causes kidney to retain water in the body

• oxytocin - promotes labor and lactation

• released into bloodstream through pituitary activation - CRH, TRH

• TRH regulates thyroid stimuating hormone

Hypothalamus: Arcuate nucleus

• releases hormones controlling pituitary (dopamine, GHRH)

• GHRH induces release of Growth Hormone in the pituitary

Hypothalamus: Dorsomedial and ventromedial nuclei

hormones that regulate feeding, temperature, reproductive behavior

Hypothalamus: Mammillary bodies

memory circuitry