Test 4 - Ch. 16 Flashcards
What is the job ob the BG?
control circuit
plan and execute voluntary movement
Goal-directed behavior
Where does the BG send it’s output?
UMN of cortex and BS
What does the BG information first go through before BS to reticulospinal and vestibulospinal?
peduncculopontine
locomotor region
Where does outputted go first before reaching cortex from BG?
Thalamus
What does the substantial migration do?
contains the cells that make dopamine and dopamine runs the basil ganglia processor. When they die the basil ganglia doesn’t work correctly. *** Powers the basil ganglia.
What are the neurotransmitters that are giving input to BG?
excitatory
glutamate
ACl
Serotonin
What are the neurotransmitters being output by the BG?
Inhibitory
GABA
What runs the processor in the BG?
Where is it synthesized?
What does dopamine do?
dopamine
substantia nigra
determines amount of inhibition, increases/decreases strength of output - globullis pallidus to other regions of brain
What are the three loops for the non-motor fxs?
- goal-directed behavior
- emotional - BG communicating with frontal lobe
- social - what is socially appropriate
Goal-directed behavior loop Where? pathway? What does it do? Presentation if damaged?
hair line
BG gets input from frontal lobe- processes it-sends the output to the thalamus - to the cortex - back to the frontal lobe- a continuing loop
Executive function in What I Want To Do, adjusts motor plan based on surroundings, helps with some learning
Hard time setting a goal, hard time making a plan, and influences motor behavior
Emotion behavior loop Where? pathway? What does it do? Presentation if damaged?
Right behind forehead
Helps to incorporate emotions and motivation into motor plan
- reward seeking behavior into motor plan
- helps to make predictions when the outcome is uncertain. (stand next to a steep ledge and get a bad feeling about what could happen, this is the loop)
- integrate with facial expressions.
Problems- cant make predictions, become impulsive and they act without considering the consequences.
Social behavior loop
Right behind eyebrows and behind eyes
- helps recognize social cues
- Helps regulates self control (helps adjust behavior and make a motor plan to respect personal space) (not pull a gun when mad in traffic)
- helps piece out what information is relevant and what is not (what can I ignore)
Problems- don’t recognize personal boundaries
What are the two motor loops for BG?
oculomotor
motor
Occulomotor loop fx?
Helps us to look where I want- create motor plan to move my eyes
Decisions about “spatial attention” and eye movement
Directs eye muscles to “look at” something (“prosaccade”)
Motor loop fx?
***Most important- circles to the pre-central gyrus- spins up the plan that finally gets shot down (sent) to the spinal cord.
- it helps regulate muscle contractions
- helps regulate how strongly we contract in light of (what I want to do, what the context is, etc)
- regulates what muscles contract, in what combination they contract, and in what order. Helps create normal synergies.
What do the internal circuits of the BG do when you make a plan to move?
It suppresses any movement that doesn’t contribute to what you want to do. It creates normal synergies to help you do what you want to do=the job of the basal ganglia.
Where do the three motor loop outputs go to?
motor thalamus - lat corticospinal and rubrospinal UMN
-inhibits motor thalamus
pedunculopontine - goes through the pedunculopontine nucleus down to the brainstem UMN (low degree of voluntary control) helps support movement but take direction from the cortex.
-Brainstem UMN wants to be active- Peduncnucleus doesn’t let the reticulospinal be active, Basal ganglia inhibits inhibitor allows the reticulospinal to be more active- counteracts an inhibitor
midbrain locomotor - control how much activation of the stepping pattern generator.
PD
Without the processor the output actually goes up. Leads to…
-too little activation of voluntary muscles (voluntary muscles not facilitated enough)
-too much activation of postural and girdle muscles.
Thalamus inhibits inhibitor which means the postural muscles are too active leads to a very stiff core and limbs that are hard to make move the way that we want to do it.
-too little activation of midbrain locomotor region- walking pattern generator is inhibited so it occasionally fails.
HD
Too much voluntary to cortical
Too little BS - postural
Extra movements in voluntary
Core Mm weak
What does it mean to feedforward?
have pt. make and think motor plan
What are the three incoming sensory systems for postural control?
Vision from cortex
Vestibular from BS/cerebellum
somatosensory from SC
