basal ganglia and cerebellum

what makes up the striatum

caudate and putamen

what is the function of basal ganglia

motor control

what specific motor control does basal ganglia have

initiation and execution of movement

regulation of muscle contraction, muscle force, multi joint movements, sequencing of movements

prevention of unwanted movements

globus pallidus has what parts

internus, gpi

externus, gpe

substantia nigra has what parts

pars compacta

pars reticularis

what are the basal ganglia structures

caudate

putamen

globus pallidus

substantia nigra

subthalamic nuclei

where are subthalamic nuclei found

midbrain diencephalic junction

paris compacta aka

SNpc

pars reticularis aka

SNpr

what are the additional roles of the basal ganglia

eye movement loop

goal directed behavior loop

social behavior loop

emotion loop

where is input to the basal ganglia received

striatum

what does caudate recieve input from

heteromodal association cortices

motor areas in frontal lobe involved in eye movement

what does putamen receive input from

primary and secondary sensory cortices in parietal lobe

higher order visual cortices in occipital and temporal lobes

premotor and primary motor cortex

auditory association cortices in temporal lobe

where does basal ganglia receive input from

cerebral cortex

SNpc

thalamus

subcortical structures

where does basal ganglia output come out of

GPi and SNpr

where does most basal ganglia output go to

VL and VA nuclei of thalamus

VL and VA nuclei of thalamus

project on to entire frontal lobe (majority to the PriMC, PreMC, SMA)

intralaminar nuclei of thalamus

additional motor relay

mediodorsal nucleus

limbic BG loop

superior colliculus

eye movement BG loop

via tectospinal tract

what are the two pathways of the basal ganglia

go and no go pathway

what is the first part of the go pathway

thalamus, gone unchecked, sends constant excitatory signals to cortex to elicit movement

what is second part of go pathway

GPi and SNpr inhibit thalamus to prevent unwanted movement

what is third part of go pathway

when a movement is needed, cortex sends info to striatum which inhibits GP and SN

GPi

globus pallidus internus

what does third part of go pathway lead to

open gate for thalamus to resume excitatory projections

what neurotransmitter is involved in go and no go pathways

GABA

when is no go pathway used

when time to stop moving

what does cortex use striatum for in no go pathway

uses striatum to inhbiti GPe

what does inhibition of GPe do

stops the GPes usual ability to inhibit the subthalamic nuclei

what is the job of the subthalamic nuclei

send excitatory signals to GPi and SN that inhibits the thalamus

what does cortex do to subthalamic nuclei in no go pathway

activates it so it sends excitatory signals to GPi and SN to further inhibit thalamus

what do the GPi and SN usually do

inhibit thalamus

what does GPe usually do

inhibit the subthalamic nuclei

what does thalamus do in basal ganglia pathways

send excitatory signals to cortex to elicit movement

what does the striatum do in go pathway

inhibit GPi and SNpr

what does inhibition of GPi and SNpr do

prevent them from inhibitting thalamus and thus let it resume excitatory projections

where does substantia nigra pars compacts have connects to

direct connections to striatum

what is big purpose of SNpc

produce dopamine for the striatum

what do the connections of the SNpc to the striatum do

modulate activity of direct and indirect pathways thru dopamine release in striatum

when is dopamine excitatory in basal ganglia

excitatory to the striatum neuons in the direct/GO pathway

when is dopamine inhibitory in basal ganglia

inhibitory to striatum neurons in indirect/no go pathway

what does the dual effect of dopamine do

decreases suppression of thalamus which causes further facilitation of movement on top of exciting the direct pathway

go pathway aka

direct pathway

no go pathway aka

indirect pathway

what does ach do in basal ganglia

inhibits dopamine when appropriate

what can ach do for movement

quickly interrupt ongoing motor behavior in response to salient environmental stimuli

how is gaba and glutamate involved in basal ganglia

primary neurotransmitter in direct and indirect pathways

what does cortex do in go pathway

sends info to striatum to inhibit gpi and snpr

what does inhibition of gpi and snpr in go pathway do

opens gate for thalamus to continue excitatory projections

where does the VL and VA nuclei project to after recieveing output from basal ganglia

entire frontal lobe

where does basal ganglia output go to

VL and VA nuclei of thalamus

intralaminar nuclei of thalamus

mediodorsal nucleus

superior colliculus

what does intralaminar nuclei of thalamus help with

additional motor relay

what does the mediodorsal nucleus do after receiving input from basal ganglia

help with limbic BG loops

what does superior colliculus do after receiving output from basal ganglia

eye movement BG loop via tectospinal tract