Basal Ganglia, Cerebellum and Movement

The basal ganglia & cerebellum both contain large collections of nuclei that?

Cerebellum signals are __

BG signals are ___

The basal ganglia & cerebellum adjust activity in ___?

Communication pathways

• ____ sends info to BG & Cerebellum

• Both respond back to cortex through ____

Basal Ganglia Nuclei

• Contain 4 structures called?

Basal Ganglia Nuclei

• The internal capsule runs between what 2 groups of nuclei?

Basal Ganglia Nuclei

• Striatum - includes?

Basal Ganglia Nuclei

• What runs together to form Lentiform nucleus

Which basal ganglia are located in cerebrum?

Which basal ganglia are located in diencephalon?

Which basal ganglia are located in midbrain?

Basal Ganglia Motor Circuit

1. ___ receive info from motor and premotor cortex- ALL INPUT GOES HERE

Basal Ganglia Motor Circuit

2. ___ process info

Basal Ganglia Motor Circuit

3. ___ sends OUTPUT to motor areas of cerebral cortex via thalamus, pedunculopontine nucleus (PPN), and midbrain locomotor region

Basal Ganglia Motor Circuit

3. Globus pallidus sends OUTPUT to motor areas of cerebral cortex via??

Basal Ganglia Motor Circuit

4. Output regulates?

Glutamate

from __, is __ to the __

GABA

from __ is __ to the __

Dopamine

from __ to __

Function?

Acetylcholine

In __

Function?

Opposite of?

D1 vs D2 receptors

• Which excite direct pathways

• Which inhibit indirect pathways

Basic BG function

• Thalamus typically sits in what type of state?

• What inhibits the Thalamus by inhibiting it (via __)?

Basic BG function

• Input to striatum is ___ (via ____)

Basic BG function

• What support what is happening in striatum (via ___)

Basic BG function

• Striatum influences GP by ___ (via __)

Which pathway turns up motor activity- allows movement?

Direct Pathway

Dopamine used at D_ receptors in striatum- inhibits the inhibitors in the GP = __ response

Direct Pathway

Role of direct pathway?

Direct Pathway

cortex excites striatum via?

Direct Pathway

Dopamine released from substantia nigra to D1 receptors in striatum- causes ___ GP inhibition via ___

Direct Pathway

____ is inhibited- stops inhibiting thalamus (disinhibition)

Which pathway turns down motor activity?

Indirect Pathway

Dopamine used at D_ receptors in striatum- ___ the inhibitors = ___ response

Indirect Pathway

Limits movement when?

Indirect Pathway

What is directly responsible for inhibiting activity of thalamus

Indirect Pathway

Indirect pathway runs from ___ to ___ to __ to __

Indirect Pathway

___ communicates with substantia nigra, which sends dopamine to D2 receptors in striatum. These ___ the inhibitors in the GP internal and ‘tighten the leash’ on the thalamus

BG Connection to Motor Neurons

Direct output?

BG to ___ to cerebral cortex to ___ of corticospinal, corticobulbular, corticopontine tracts

BG Connection to Motor Neurons

Postural muscles

• BG to __ to __

BG Connection to Motor Neurons

Locomotor Pattern Generators

• BG to __ to __

What are the 5 basal ganglia loops

Which loop - movement selection and action

Basal ganglia loops

• which is decisions about eye mvmt & initiation of fast eye movement (saccades)

Basal ganglia loops

• Goal-directed behavior, perceptual, decisions & plans, decides on actions in context

Basal ganglia loops

• recognition of social disapproval, self-regulatory control, attention, learning, selecting relevant knowledge

Basal ganglia loops

• Identifies value of stimuli, reward guided behavior, pleasure seeking

Motor loop path

Motor cortex → Striatum (caudate) → Thalamus → Motor cortex

Which loop controls Involuntary saccades & fast eye movement

Oculomotor loop path

Frontal Eye field → Caudate → Substantia Nigra → Thalamus → Eye field

Executive (Cognitive) Loop path

PFC → Caudate → GP→ Thalamus → PFC

Which loops is involved in motor learning?

Which loop Evaluates info for making perceptual decisions, planning, choosing actions in context

Behavior Flexibility & Control Loop path

PFC & OFC→ Caudate → GP→ Thalamus → PFC & OFC

Which loop did Goal oriented behavior & learning

Which loops Learning & dictating activity based on reward

Limbic Loop path

Inferior PFC→ Nucleus Accumbens → VTA in Ventral Striatum→ Thalamus → Inferior PFC

Which loop links limbic, cognitive, motor system

Which loop plays a Role in reward & addiction

Which loops gives Motor expressions to emotions - facial expression & posture

Which loop Relies heavily on dopamine

Limbic loop

BG Movement Disorders

Parkinsons Disease

Affects?

Main symptom?

Parkinsons Disease

Pathogenesis

• Death of ___ = ___ = ___

• Death of ___ = _____

Huntington’s Disease

Main symptom?

Huntington’s Disease

Pathogenesis

• What kind of gene?

• Gene causes degeneration of?

Huntington’s Disease

Pathogenesis

• __ levels are diminished = outflow of _ is not regulated and levels become _

Huntington’s Disease

Signs?

Lesion of subthalamus and caudate causing disinhibition of neuronal activity between thalamus and cortex

Flailing, violent movement of contralateral extremity

Lesion of caudate and putamen

Sudden, involuntary movement –dancelike

• Axial and proximal limbs- shoulder shrugs, moving hips, crossing legs

• In face- grimacing, eyebrow raising, tongue protrusion

Caused by lesion to caudate and putamen with cortical involvement

Slow, aimless, purposeless mvmt of distal musculature

Twisting and turning; continuous quality

Linked to overactivity in globus pallidus

Linked to overactivity in globus pallidus

Dystonia

Repetitive muscle contractions cause twisting, abnormal postures

Dystonia

Related to chronic treatment with dopamine receptor antagonists  (antiemetics, neuroleptics)- dopamine receptors become blocked

Tardive dyskinesia

Rhythmic, repetitive mvmt- can be choreiform, dystonia, tics, or myoclonus

Often tongue or lip smacking, chewing, grimacing

Tardive Dyskinesia

Specific set of striatal neurons becomes overactive

Testing shows abnormal metabolic activity in the orbitofrontal cortex, the anterior cingulate/caudal medial prefrontal cortex, and the caudate nucleus

Repetitive, brief, involuntary, purposeless movement – can be suppressed

Tics/Tourette’s