Basal Ganglia Flashcards
what are the 4 basal ganglia nuclei
- Caudate nucleus
- Lentiform nucleus
- Colostrum
- Amygaloid nucleus
Where is the caudate found and what is its function
-located lateral to thalmus. Has body that is on floor of lat ventricle and tail that forms roof of inf horn of lat ventricle
Function- help us learn new mvmts + perform mvmts of intent
What are the sections of the Lentiform nucleus
Outer- putamin
Inner- globus pallidus (which is further divided into inner and outer portions)
Where is the lentifotm nucleus located
Just lat to internal capsul and medial to claustrum
What is the corpus striatum made up of
Made of caudate nucleus and lentiform nucleus + the connection bw them (nucleus accubens)
Function of amygdaloid body
Involved in emotional learning and memory
Where is claustrum located and its function
Bw putamen and cerebral cortex of insula
selective attention
What is the nucleus accubens and function
Connection bw caudate nucleus and lentiform nucleus
center of addiction
Corticostriate pathway
All parts of cerebral cortex to caudate nucleus and putamin
Stimulatory
Nigrostriatal pathway
Substantia nigra to caudate nucleus and putamin
Stimulatory
Striatonigral pathway
Efferent connection from caudate and putamin to substaantia nigra
inhibitory + stimulatory
Striatopalidum path
From putamin to globus pallidus
Inhibotory
Subthalamic palido connections
subthalmus to pars interna of globus palladus
If subthalmus is not inhibited by pars externa of globus paladus, subthalmus will send extitaory signals to pars interna
Pallidofugal connection
globus palidus to ventral ant thalamic nucleus
inhibitory
Thalamocotical connection
Thalmus to cerebral cortex (primary motor)
Stims motor cortex
Steps of direct pathway
Motor cortex stims
Striatium which inhibits
Globus pallidus (int)- So no Gaba release
Thalmus is stimed which stims Motor cotex
Effect of Substania nigra on direct path
since their are D1 receptors on striatum, the dopamine released will make the striatum less polarized allowing them to execute quicker.
Steps of the indirect pathway
Motor cortex stims striatum which inbits Globus palidus ext (no Gaba release) This stims ST nucleus which stims Globus palidus int (releases GABA) inhibits thalmus
What are the effects of substantia nigra on indirect path
Striatum have D2 receptors, when dopamine binds it hyperpolarizes it which inhibits path but double negative effectively activates path
What happens in parkinsons disease
affects direct path
Causes hypokinetic disorder (slow mvmt)
also due to substantia nigra destruction (cant stim striatum)
What happens in Huntingtons disease
affects indirect path
if disturbed causes hyperkinetic mvmts ( balistic mvmts etc)
