Lecture 13: Modulation for movement by the basal ganglia and cerebellum Flashcards
What two structures modulate activity of the upper motor neurons
Cerebellum and basal ganglia
T or F: cerebellum and basal ganglia generate movement
False!
The ___ sends information to the cerebellum and basal ganglia
Motor cortex
The cerebellum and basal ganglia send information back to the motor cortex through the ___
Thalamus
T or F: the effects of cerebellum and basal ganglia are similar
False, opposite
The contribution of the basal ganglia and the cerebellum allow for ___, ___ movements
Smooth and coordinated movement
Disturbances in either the cerebellum or basal ganglia will create ___ disorders
Motor
What are the 5 parts of the basal ganglia
- Caudate nucleus and putamen
- Globes pallidus
- Substantia Nigra
- Subthalamic nucleus
- Thalamus
What role does the caudate nucleus and putamen play in the basal ganglia
Receives excitatory input from the cortex
What two structures make up the globus pallidus
External/outer segment and internal/inner segment
What two structures make up the substantia nigra
Pars compacta and pars reticularis
What does the thalamus do in the basal ganglia
Sends modulated excitatory feedback to the cortex
describe the direct pathway
1.cortex signals to striatum (putamen)
2. Striatum sends inhibitory signal to globulus pallidus (internal) and substantia nigra (pars reticulata)
3. Those two structures send an inhibitory signal to the thalamus resulting in disinhibition of thalamus
4. Thalamus sends stimulatory signal to cortex to increase activity in cortex
5. Cortex sends out signal to upper motor neurons
Describe the indirect pathway
- Cortex signals to striatum
- Striatum sends inhibitory signals to globulus pallidus which inhibits subthalamic nucleus
- Subthalamic nucleus sends activating signal to globulus pallidus and substantia nigra
- Activated globulus pallidus and substantia nigra will NOT disinhibit thalamus
- Thalamus will decrease activating signal sent back to cortex
What is disinhibition
Inhibition of inhibition
What does disinhibition result in
Reduction in inhibition that leads to an increase in feedback from the thalamus to the cortex
Thalamus output is always___
Excitatory
Direct pathway ___thalamic excitation of the cortex
Increases
The indirect pathway ___ thalamic excitation of the cortex
Decreases
What neurotransmitter does the cortex release onto the striatum
Glutamate
What neurotransmitter does the substantia nigra release onto striatum
Dopamine
Damage to the substantia nigra can cause what kinds of diseases
Parkinsonian
What neutrotransmitter do the striatum interneurons release
Acetylcholine
What neurotransmitter does the striatum release onto the globus pallidus
GABA