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13 Cards in this Set
- Front
- Back
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What are the 4 major components of the basal ganglia?
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Striatum (caudate and putamen)
Globus Pallidus (internal and external segments) Subthalamic nucleus Substantia nigra (pars reticulata and pars compacta) |
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Briefly describe the neurochemistry (NTs) of the basal ganglia
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Predominantly GABAergic
STN is glutamatergic Dopamine modulates striatum |
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describe the interaction between input neurons, dopamine projection neurons, and medium spiny neurons
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dopamine projections 'gate' the excitatory input from input neurons (and modulate short and long term changes)
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What are the two major characteristics of the basal ganglia loops?
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the functional territories are grouped topographically and they are well segregated
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Briefly describe chemistry of D1 and D2 channels
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G(s) coupled --> opens Ca channels, depolarizes cell
G(i/o) coupled --> IP3 --> intracellular Ca --> closes Ca channels, hyperpolarizes cell |
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What is the resting activity like of neurons in the GPe, STN, GPi, and substantia nigra?
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tonic, intrinsic activity (so that it can be modulated up or down)
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What is the role of cholinergic interneurons in the basal ganglia?
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tonically active, regulate synaptic plasticity; "when to learn signal" during classical conditioning
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What is the role of GABAergic striatal interneurons?
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regulate the spatiotemporal pattern of medium spiny neuron activity
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Describe the basal ganglia help generate associative learning
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bursts of dopamine follow rewards (or cue after conditioning) that have global effect on striatum --> leads to supra-additive signal --> changes strength of corticostriatal synapses (memory)
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Basic characteristics of Parkinson's disease
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rigidity, shuffling gait, postural instability; loss of dopaminergic neurons in substantia nigra; many proposed causes
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Basic characteristics of Huntington's disease?
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hyperkinesia followed by akinesia, dystonia, and dementia; 35 or more repeats of CAG; striato-GPe neurons degenerate early
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Possible treatments of Parkinson's?
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L-DOPA, deep brain stimulation of subthalamic nucleus using high frequencies
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Basic characterisitcs of dystonia?
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rigidity due to co-contraction; may be related to dysfunction in timing and extent of D1/D2 pathways
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