5
Psychologie (Subject) / functional task 2 (Lesson)
- components of the basal ganglia caude + putamen (striatum) globus pallidus external globus pallidus internal subthalamic nucleus substantia nigra
- important neurotransmitter involved GABA --> inhibitory glutamate --> excitatory
- direct pathway Making movement --> thalamus is normally under inhibition, GOAL: take away inhibition, so that we can move! Cerebral cortex ---excitatory neuron --->striatum (excited) --- inhibitory neurons become more active --> globus pallidus internal (more inhibited) --- can not inhibit thalamus as much as normally ---> Thalamus (more excited) --- excites ---> frontal cortex substantia nigra ---D1 ---> striatum
- indirect pathway Not making movement --> tightening leash on thalamus by chatting w global pallidus internal Cerebral cortex ---excites ---> striatum (more activity) --- inhibits ---> Globus pallidus external (turns down activity) --- can't inhibit as much as normally ---> subthalamic nucleus (gets more excited) --- excites ---> globus pallidus internal (more active as usually) ---> inhibits MORE thalamus --- less excites ---> Frontal cortex substantia nigra --- D2 (inhibits )---> Striatum ---> reversed effect of indirect pathway --> adjusts the leash!
- Parkinson's disease Hypokinetic movement disorder = failure of the disinhibtion normally mediated by the basal ganglia caused by the loss of dopaminergic neurons --> inhibitory outflow of basal ganglia is abnormally high --> timely thalamic activation less likely diminshed facial expressions, lack associated movement movement is difficult to iniated and difficult to stop again
Advertisement