Task 2 Flashcards
Caudate
multimodal asoociatoion cortices, motor areas in PFC that control eye movement => Neurons fire prior to eye movement
Putamen
input from somatosensory visual, premotor & motor cortices and aufitory association areas=> neurons frie prior to limb/ trunk movemnet
Dpaminergic modilation
Excitatory input to spinys that project to internal globus pallidus (= direct pathway)
D1 receptor cells (G-protein stimulates cAMP) EPSP
Increased responsiveness to cortical input
Inhibitory input to spinys that project to external globus pallidus (= indirect pathway)
D2 receptor cells (G-protein inhibits cAMP) IPSP
Decreased responsiveness to cortical input
Decrease inhibitory outflow
Reward modulation: when goal of movement is associated with larger reward, dopamine is released in the striatum strengthens connections in direct pathway (motor program more likely to get the “go”)
Drop in dopamine when something went wrong strengthens connection in the indirect pathway
PARKIMNSON
substania nigra degenerates=> inhiboty ouput to extrenal incresed, inhibitory output to internal decresed=> more inhibition on thalamaus
Huntimgton inhibitory pathway to extrenal sedgment decreses
nhibitory pathway to extrenal sedgment decreses, inhibitory output to thalamus decreses
4 loops
Body movement loop
Occulomotor loop
Prefrontal loop
Limbic loop
Body movement loop
Motor premotor, somatosensory cortex=> Putamen=> Lateral globus pallidus=> Ventral lateral n& vebntral anterior nuclei
Occulomotor loop
posterior parietal prefrontal cortex , frontal eye field=> Caudate=> Globus pallidus internal segment => mediodorsal & ventral anterior nuclei
Prefrontal loop
Dorsolateral prefrontal cortex=> anterior caudate=> Globus pallidus=> mediodorsal & ventral anterior nuclei
intitiation & termination of cognitive processesplanning WM
Limbic loop
Amygdala , anterior cingular ,orbito frontal cortex, hippocmapus=> Ventral striatum=> Ventral palladium => mediodoral nucleus
transition from one modd to naother regulates emotional and emotional behavioiur
medium spiny neurons
These neurons exhibit very little spontaneous activity and must simultaneously receive many excitatory inputs from cortical and nigral neurons to overcome the stabilizing influence of this potassium conductance (which remains a stable resting membrane potential, close to depolarization). When they do become active, their firing is associated with the occurrence of a movement.
2 most common areas of deep btrain stimulation
subtahlamic nucleus and globus pallidus internaö
BG othr input
Thalamus brainstem other spiny, intrinsic interneurons, substania nigra pars compacta