Thalamus-Cortex

Question 1

Thalamic Non-specific nuclei

Answer 1

Mainly the intralaminar nuclei that send non-specific projections to cerebral cortex after inputs from basal ganglia.

Question 2

What kind of potential is produced by low threshold calcium current

Answer 2

all or non triangular shaped potential wiht a low threshold called low threshold spike

Question 3

What are the two functions of thalamus

Answer 3

Question 4

What is basic concept of sensory and motor information flow in cortex

Answer 4

A is old model, B is modern model

Question 5

Location of nucleus reticulares on coronal cut

Answer 5

Question 6

General Design of Thalamocoritcal circuits

What kind of neuron constitutes 80% of all nuclei

Answer 6

Glutamatergic excitatory projections make up 80%

Also GABAnergic of nucleus reticularis surrounding the thalamus providing inhibitory

Question 7

Thalamic relay limbic nuclei

Answer 7

maiary obdies - anterior nucleus - cingulate gyrus

Question 8

Organization of cortex - neurons from layers 1,3,5,6 go out to what areas respectively

Answer 8

1 - Other cortical ares

3 - Other cortical areas, opposite hemisphere

5 - Subcortical structures

6 - Thalamus

Question 9

Giant pyramidal cells are called

Answer 9

Betz cells

Question 10

What are the two fundamental properties of bursting

Answer 10

all-or-none and refractory period.

Question 11

Onset of sleep defined by?

Answer 11

Diminshed amplitude of alpha waves in occipital EEG channel and change in firing pattern

Question 12

Wake to sleep 2 main changes in TC cells

Answer 12

Tonic to bursting, rhythmicity

Question 13

How do Thalamic cells respond differently to sensory signals in Wake and Sleep

Answer 13

Unreliable bursts. Opposite of fixed reliable single spike in wake

Question 14

Agranular cortex more likely to be found?

Granular cortex more likely to be found in what region?

Answer 14

Question 15

What ist he dramatic change in thalamus firing pattern from wake to sleep

Answer 15

High frequency low amplitude single spikes to burst firing mode

Question 16

EEG - General measure of neural activity

Answer 16

Spike wave pattern

Question 17

What layers are traveresed in vertical flow of information of cortex

Answer 17

Granular (4) - Super Granular (2/3) - infragranular (5/6) - Out of cortex

Question 18

Wake to Sleep 3 main changes in EEG

Answer 18

amplitude, frequency, synchronization

Question 19

What is basis of cytoarchitecture and how many layers are there in neocortex

Answer 19

Basis is layers from differences in cell packing density, presence of fiber bundles.

6 Layers in neocortex but only Layer 4 aka granular layer used

Question 20

How does a thalamic cell in burst mode respond to repeated stimulus

Answer 20

Question 21

Thalamus 3 Sensory Relay nuclei

Answer 21

Auditory - Medial geniculate

Visual - Lateral geniculate

Somastosensory - Ventrobasal

Question 22

Thalamus Motor Relay nuclei

Answer 22

Ventral anterior and ventral lateral

Question 23

Changes in EP produced by disease usually lead to what EEG finding

Answer 23

Delayed response in evoked potentials

Question 24

Thalamus limited laterally and internally by

Answer 24

Question 25

Sleep EEG characterized by

Answer 25

Low activity, high amplitude

Question 26

What channels are active when you hyperpolarize TC cells

Answer 26

Calcium channels

Question 27

3 States of the T-channel and how they contribute to the rhythmic burst firing mode in TC cells

Answer 27

Question 28

How are evoked potentials measured

Answer 28

Smaller but usally determiend by averaging techniques of othe recordings

Question 29

Anatomic Divisions of the Thalamus (5)

Answer 29

Internal medullary divides the Medial and Lateral Nuclei Also the Anterior group of nuclei Intralaminar nuclei reticular nucleus

Question 30

Thalamic 2 association nuclei

Answer 30

Pulvinar - serves parietal-occipital-temporal assocation cortex mediodorsal - serves prefrontal cortex

Question 31

What are the two types of excitatory cells that use Glutamate neurotransmitter

Answer 31

Granular cells aka spiny stellate in layer 4 Pyramidal cels that are 80% of cortical cells

Question 32

Columnar organization shows

Answer 32

Visual cells respond to same stimulus in one vertical field. Shows massive parallel processing device

Question 33

Areas of cortex receiving relay vs association nuclei

Answer 33

Question 34

What nuclei does not have any projections outside of the thalamus

Answer 34

reticular nucleus

Question 35

General pattern of oscillatory mode that is due to similarites with heart calcium channels

Answer 35

A rise in (Ih) current -\> Low threshold calcium (It) opens depolarizes Activating sodium/potassium. Depolarization inactivates (Ih) - repolarization then hyperpolarization bc Ih was incativated. Hyperpolarization de-inactivates It and activates Ih reaching level for low threshold calcium to fire again

Question 36

Functional consequence of rhythic bursting in thalamus and cortex

Answer 36

Global synchrony in thalamacortical networks

Question 37

What maintains the thalamic membrane potential during wake and is less active in sleep

Answer 37

brainstem and basal forebrain neuromodulatory systems releasing acetylcholine and noradreniline. Less activation allows K current to dominate and lead to hyperpolarization.

Question 38

What are the 2 main types of thalamic cells?

Answer 38

Thalamocortical projections - excitatory and projecting to cortex Reticular thalamic neurons - inhibitory projecting reciprocally to thalamic nuclei