Thalamus tract course Flashcards
What are the standard grouping of the thalamic nuclei?
Non specific
Associative
Limbic
Motor planning & relay control
Sensory relay
Gatekeeper
What are the nonspecific nuclei?
midline nuc. intraminar nuc. (centromedian; CM)
What are the associative nuclei?
dorsomedial nuc. (DM) pulvinar nuc. lateral posterior nuc. (LP)
What are the limbic nuclei?
anterior nuc. lateral dorsal nuc. (LD)
What are the motor planning and relay control nuclei?
ventral anterior nuc. (VA) ventral lateral nuc. (VL)
What are the sensory relay nuclei?
ventral posterior lateral nuc. (VPL) ventral posterior medial nuc. (VPM) lateral geniculate nuc. (LGN) medial geniculate nuc. (MGN)
What is the Gatekeeper nuclei?
reticular nuc.
What is the input and output of the non specific nuclei?
arousal (cortical excitability)
input- spinal cord and brainstem reticular formation
output- widespread, diffuse projection to cerebral cortex and basal ganglia
What is the input and output of the associative nuclei?
dorsomedial nucleus - affect, emotion, motivation, behavior, olfactory interpretation
Input - amygdala, entorhinal cortex
output - prefrontal association complex
What are the affects of a dorsalmedial lesion?
may relieve anxiety states. Affects of DM lesion parallel affects of prefrontal lobotomy (which disrupts prefrontal connections to thalamus. Also, DM degenerates after prefrontal lobotomy
What is Karsakoffs syndrome?
Bilateral medial degeneration of thalamus in chronic alcoholism accompanied by thiamine deficiency
Effects include anterograde amnesia in addition to behavioral problems
What is the input and outputs of the associative (lateral posterior nucleus)nuclei?
lateral posterior nucleus – visual integration, interpretation & response
input - superior colliculus and pretectum
output superior posterior association complex
What is the input of associative (pulvinar) nuclei?
pulvinar nucleus – visual integration, interpretation & response
Input- retina, pretectum, superior colliculus and visual association areas
output- ocipital, parietal, temporal association cortex
What is the input/output of the limbic (anterior nucleus)?
anterior nucleus – relay in Papez circuit of emotion and memory
input-mammillary nucleus of hypothalamus (via mammillothalamic tract)
Output- cingulate gyrus
What is the input/output of th elimbic (lateral dorsal nucleus)?
lateral dorsal nucleus (LD) – limbic functions including emotion
input -hippocampal formation
output-cingulate gyrus
What is the input/output of the motor planning and control relay(ventral anterior (VA) and ventral lateral(VL)) nucleus?
ventral anterior (VA) nucleus & ventral lateral nucleus (VL)
input- basal nuclei & cerebellum
Output- premotor& supplementary motor cortex
What is the input/output for sensory relay (ventral posterior lateral nucleus) ?
§ventral posterior lateral nucleus (VPL) – descriminative touch, conscious proprioception, pain & temperature, limbs & trunk
input- conscious somatosensory from trunk and limbs
ouput-somatosensory cortex for limbs and trunk
What is the input/output for sensory relay (Ventral posterior medial nucleus)?
ventral posterior medial nucleus (VPM) – descriminative touch, conscious proprioception, pain & temperature, and taste from face-head
input-conscious trigeminothalamic & gustatory pathways
output-somatosensory cortex for face + anterior insula (taste)
What is the input/output for sensory relay(lateral geniculate) nucleus?
lateral geniculate nucleus - relay in primary visual perception
input - optic tract
output- primary visual cortex
What is the input/output for for the sensory relay (medial geniculate) nucleus?
medial geniculate nucleus - relay in primary auditory perception
input- inferior colliculus (via brachium)
output - primary auditory cortex
What is the input/output for the gatekeeper (reticular) nucleus?
reticular nucleus – regulate thalamocortical-corticothalamic communication
input -thalamocortical and corticothalamic collaterals
output- thalmic nuclei and cortex
Where does thalamocortical and coticothalamic pathways pass?
What is the function of the function of the reticular nucleus?
Thalamocortical and corticothalamic pathways pass through and communicate with the reticular nucleus neurons via axon collaterals
Reticular nucleus probably modulates (regulates) the exchange of information between the thalamus and cortex
What may reticular fibers may be indicated in what pathophisiology?
schizophrenia.
