SPRING Frontostriatal Disorders

Question 1

define executive function

Answer 1

encompasses activities we need to do as humans

regulation and motor control

Question 2

what is the basal ganglia

Answer 2

group of complect grey matter structures beneath the cortex- protected by neocortex
highly connected to frontal cortex with relay system between f.cortex and thallamus
regulates higher order cog function and execution of complex motor strategies - in charge of overall processess but not direct involvement

Question 3

what makes up the ventral striatum of the basal ganglia

Answer 3

caudate nucleas (inside putamen)
nucleas accumbens ('reclining nucleas')
putamen

Question 4

what makes up the lenticular nuclease of the basal ganglia

Answer 4

putamen
globus pallidus (GPe-external, GPi-internal)

Question 5

what makes up the whole of the BG

Answer 5

caudate nuclease
nucleus accumbens
putamen
global pallidus (GPe/GPi)
subthallamic nucleas
substantia nigra (pars reticula(SNr)/Compacta(SNc)

Question 6

what are the different frontostriatal circuits

Answer 6

DLPFC (cognitive)
motor
oculomotor (eye)
orbitofrontal (Affect)
anterior (limbic) cingluate (Affect) 
- all pass through the striatum and are densely linked to the frontal cortex

Question 7

BG involvement in frontostriatal circuits

Answer 7

intermediatary for communication between cortex and thallamus to initiate activity
indirect role in modulating and regulating the motor cortex to the skeletal system
enables the movement/beh to run smoothly and filters out unnecessary/unwanted

Question 8

how does the BG connect to the frontostriatal circuits

Answer 8

BG same function across circuits

topographic organisation of PG mens pathways are segregated and haves specific patterns of neuronal firing per circuit

Question 9

motor system and BG research in rats

Answer 9

motor system has systematic projections that are specific to its function
parallel to other systems
thought to be the same in all other circuits

Question 10

what is the general flow of info for frontostriatal circuits through the BG

Answer 10

input from cortex via excitatory gluatmate

to BG - CN/putamen/VS/NA - output to GPe/GPi - thallamus (relat to VL/VA) & back to cortex

Question 11

damage to BG

Answer 11

interferes with appropriate application of actions - BG finetunes therefore:
slower/move too much, tremors, extra movements etc
qualitatively different behaviours

Question 12

damage to DL PIFC

Answer 12

involved in cognitive circuit/executive function/top down control
affect WM and lead to subcortical dementia
problems responding to external situations and executing internal willpower to perform a behaviour
Absence of external direction - Being able to respond and initiate
Lack of insight- poor self monitoring
Cant complete problem solving acitivities ie coming up with new ways to tackle a logical problem etc – must have to be able to stop previous response set, need executve control to remove irrelevant info and come up with new strategies

Question 13

deficits in DLPFC

Answer 13

dysexecutive syndrome
problems with organisation, maintaining and shifting attention, mental flexibility, WM, reasoning and personality (not respoding to environment in the same way)

Question 14

symptoms of subcortical dementia

Answer 14

Bradyphrenia
Perseveration – stuck in thought, repetitive, loop of thought
Executive function deficits
Language and visuospatial preservation
Mild amnesia
Social functioning often preserved
Neurological symptoms of the primary disorder

Question 15

what is hypokinesia

Answer 15

lack of movement
cant initiate (akinesia), cant execute (bradykinesia) and low muscle tone (hypotonia)
IE PARKINSONS

Question 16

what is hyperkinesia

Answer 16

excess of movement
involuntary movements (dyskinesia), dystonic and dance like movementa (chorea) slow continuous movements (athetosis)
IE HUNTINGTONS

Question 17

motor ciruit deficits

Answer 17

hypokinesia: parkinsons

hyperkinesia : huntingtons

Question 18

occulomotor deficits

Answer 18

delayed saccade or increased no saccades

Question 19

what is the orbitofrontal circuit involved in

Answer 19

personality and mood affect
social restraint, self monitoring and inhibition of external cues
Suppression of irrelevant stimuli & prepotent responses
Recognition of reinforcing stimuli & S-R learning
Coding for change in reinforcement contingencies
Emotionality & personality

Question 20

damage to the orbitofrontal circuit

Answer 20

responding differently to stimuli in environment and can be seen as affecting emotions and personality
Obsessions compulsions
Disinhibition of thinking
Improper emotions 
	- outbursts of aggression
	- sociopathy, impulsiveness
	- obsessions & compulsions
	- excessive pleasure seeking & insensitivity to risk
	- inappropriate lewdness
	- sporadic hypomania
	- fatuous euphoria
Failure to respond to social cues
Lack of empathy
Cognitive/Behavioural disinhibition

Question 21

what is the anterior cingulate cortex involved in

Answer 21

motivational affect

Question 22

deficit in anterior cingulate cortex circuit

Answer 22

Tend to not respond very much to the outside world
Basic urges don’t get much of a response – apathy at a physiological level and simply not engaging
Decreased motivation & drive
Reduced initiative
Indifference to pain, thirst, hunger
Lack of verbalisation and response to commands
Akinetic mutism/abulia

Question 23

parkinsons circuitory deficits

Answer 23

underactive motor and occulomotor, DLPFC and OFC-ACC circuits

Question 24

huntontons circuitory defcits

Answer 24

overactive motor, DLPFC and OFCACC circuits

Question 25

OCD/ADHD/TOURETTES/AUTISM circuitory deficits

Answer 25

overactive ACC path, underactive OFC path

Question 26

Alz circuitory deficits

Answer 26

hypofunction of DLPFC

Question 27

schizophrenia circuitory deficits

Answer 27

• Decreased activity in the DLPFC circuit

* Increased activity in the ACC circuit

Question 28

depression circuitory deficits

Answer 28

• Decreased activity OFC, ACC, DLPFC circuit