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Flashcards in Thalamus Deck (48):
0

Sensory specific nuclei of thalamus (4)

Ventral posterolateral (VPL)
Ventral posteromedial (VPM)
Lateral geniculate (LGN)
Medial geniculate

1

Motor specific nuclei of thalamus (2)

Ventral lateral (VL)
Ventral anterior (VA)

2

Association nuclei function: (3)

1. Connect w/ association cortical areas
2. Receive input from many other thalamic nuclei
3. Connections w/ cortex that are not directly reciprocal

3

Association specific thalamic nuclei (2)

Mediodorsal nucleus
Pulvinar

4

Limbic specific nuclei

Anterior group (AN)
Laterodorsal nucleus (LD)

5

Non-specific thalamic nuclei

Midline nuclear group
Intralaminar group (centromedian nucleus)

6

Ventral posterolateral nucleus
Input:
Output:

Input: Spinothalamic = pain/temp, DCML = discriminative touch

Output: Reciprocally connected w/ postcentral gyrus (limb and trunk of somatosensory cortex)

7

Ventral posteromedial nucleus (VPM)
Input:
Output:

Input:
Trigeminothalamic system: sensory from face
Taste from NTS via dorsal longitudinal fasciculus -->Medial, parvicellular portion of VPM (VPMpc)

Output:
VPM: Face portions of somatosensory cortex (postcentral gyrus)
VPMpc: anterior part of insula (primary gustatory cortex)

8

Lateral geniculate nucleus (LGN)
Input:
Output:

Input: Visual (optic tract) of contralateral visual field
Output: Primary visual cortex (V1) in occipital lobe (cuneus and lingual gyrus) via optic radiation

9

Lateral geniculate nucleus
Magnocellular projections from layers ___ and ___ convey info about ____ from ____

Layers 1 and 2
Movement, depth and small differences in brightness
Retinal rods

10

Lateral geniculate nucleus
Parvocellular projections from layers ___ to ___ convey ____ from ____

Layers 3-6
Fine details about form and color
Retinal cones

11

Inputs from temporal retina end (ipsilateral) end in layers ___

2, 3, 5

12

Inputs from nasal retina end (contralateral) end in layers ___

1, 4, 6

13

Medial geniculate nucleus
Input:
Output:

Input:
Auditory input from inferior colliculus

Output:
Auditory cortex in Heschl's gyrus of temporal lobe via auditory radiations

14

Ventral lateral nucleus (VL)
Input:
Output:

Input:
Crossed output of cerebellar deep nuclei via thalamic fasciculus

Output:
Primary motor cortex in precentral gyrus

15

Ventral anterior nucleus (VA)
Input:
Output:

Input:
Inhibitory input from ipsilateral basal ganglia via thalamic fasciculus

Output:
Lateral part: trunk and limb regions of premotor cortex
Medial part: premotor, frontal eye fields, cingulate and parietal cortices

16

Lateral part of ventral anterior nucleus (VA) receives input from:

globus pallidus internal segment (GPi)

17

Medial part of ventral anterior nucleus (VA) receives input from:

Sustantia nigra pars reticulata (SNr)

18

Thalamc fasciculus is a composite bundle containing _____ fibers that is insinuated between ____ and ___.

Cerebellothalamic (Crossed)
Pallidothalamic (Uncrossed)

Thalamus, zona incerta

19

Basal ganglia disease on motor function are expressed (ipsilaterally/contralaterally)

Contralaterally

20

Cerebellar disease are expressed (ipsilaterally/contralaterally)

Ipsilaterally

21

Mediodorsal nucleus (MD)
Input:
Output:
Function:

Input:
Amygdala, olfactory cortex, ventral pallidum (basal forebrain)
Output:
Prefrontal cortex and limbic system
Function:
Attention, planning, organization, abstract thinking, multitasking, active memory

22

Lesions affecting mediodorsal nucleus results in ____

apathy
memory changes
difficulty in switching tasks

23

Pulvinar
Input:
Output:
Function:

Input:
Retina, superior colliculus, spinothalmic tract (indirectly)
Output:
Parietal, temporal, occipital lobes
Function:
Language processing, visual perception, pain perception

24

Anterior group (AN)
Input:
Output:
Function:

Input:
Para-hippocampal region via fornix and mammillary bodies (mammillothalamic tract)
Cholinergic input from midbrain

Output: Cortex of cingulate gyrus

25

Laterodorsal nucleus (LD)
Input:
Output:
Function:

Input:
Parahippocampal region via fornix
Output:
Parietal cortex, retrosplenial cortex
Function:
Spatial learning and memory

26

Korsakoff's syndrome caused by:

Severe degenerative changes in anterior group
Changes in mammillary bodies

27

Spatial and context-dependent memory formed from distributed neural system made from: (6)

anterior group, laterodorsal nucleus, mammillary bodies, fornix, mammillothalamic tract, cingulate and retrosplenial cortices

28

Midline nuclear group
Input:
Output:
Function:

Input:
Pain-related info from midbrain PAG
Cholinergic elements of Ascending Reticular Activating System
Locus ceruleus (NE) and midbrain raphe (5-HT)
Output:
Diffusely to cortex and striatum
Thalamic paraventricular nucleus connected w/ suprachiasmatic nucleus
Function: General cortical arousal

29

Intralaminar group (centromedian nucleus)
Input:
Output:
Function:

Input:
non-reciprocal input from motor cortex
Cholinergic input from ARAS
Output:
Reciprocally connected w/ striatum and basal ganglia
Function:
Attention to motor tasks

30

Lesions of centromedian nucleus lead to ____

Unilateral motor neglect

31

Thalamic relay neurons on burst mode are ____
Function:

Hyperpolarized, "de-inactivated"
Less able to pass incoming signal to cortex BUT maximized initial stimulus detection

32

Thalamic relay neurons in tonic mode are ____
Function:

Depolarized
Better linear summation (pass signal to cortex) BUT poorer detectability for new stimuli

33

Function of intralaminar thalamic cells

Hyperpolarize thalamic relay neurons via GABAb receptors --> primed for bursting activity

34

Switch between burst mode and tonic mode is controlled by ___

Modulatory afferents to these cells = thalamic reticular nuclei (TRN) + feedback pathway from cortex

35

Thalamic reticular nuclei (TRN) are innervated by ____
Involved in:

Cholinergic fibers of ARAS from midbrain

Coordinating information traffic from relevant sensory channels

36

During slow-wave sleep, TRN keeps all thalamocortical neurons in ____ mode

burst --> can't pass signals

37

During wakefulness, TRN _____

selectively switches populations of relay neurons from burst to tonic mode

38

Blood supply to thalamus is mostly from ____

Posterior cerebellar artery

39

Infarct in inferolateral a. (branch of PCA) will cause (4):

Ataxia
Hemiparesis
Hemianesthesia
Hemihyperesthesia

40

Infarct in the paramedian a. will cause (3):

Hemiparesis (motor neglect)
Memory/learning problems
Apathy

41

Infarct in anterior (tuberothalmic) a. will cause (3):

Amnesia
Language difficulty
Euphoria/mood

42

Contralateral hemianesthesia caused by:

VPL/VPM damages

43

Contralateral hemianopsia (blindness) caused by:

Lateral geniculate nucleus (LGN) damage

44

Contralateral hemichorea caused by:

VA/VL damage

45

Contralateral hemitremor and hemiataxia caused by:

VL damage

46

Retrograde/anterograde amnesia caused by:

MD, midline nuclei

47

Dejerine-Roussy Syndrome characterized by: (5)

Hemi-ataxia
Hemi-tremor
Hemi-chorea
Hemi-anesthesia 2 pt touch
Hyperesthesia: exaggerated pain and temp.