Exam 2- Movement Flashcards
How did John Pepper walk off his Parkinson’s and why did this work?
Pepper had to pay close conscious attention to each movement by activating the prefrontal and other cortical circuits.
-The basal ganglia knit together and automate complex sequences of movements and thoughts
-Pepper’s basal ganglia is damaged, so he has to focus on moving intentionally by looking at his movement
This bypasses the basal ganglia
How did animal research lead to current hypotheses about the association between exercise and Parkinson’s? Be able to describe the various studies, but you don’t need to remember the names of all of the scientists that made these discoveries. What methods were used in these studies?
Hebb- kept rats as pets; they performed better on problem-solving tests than rats in cages
Rosenzweig- animals raised in enriched environments have heavier brains
Gage- 45 days in an enriched environment preserved neurons in hippocampus
Praag- running wheels contributed to birth of new neurons in hippocampus
Hannan- enriched environments delayed onset of symptoms of Huntington’s disease in mice
Taub- put good arm into cast to help people use paralyzed arm due to stroke
Tillerson, Miller, Zigmond- animals with only 20% of dopamine loss will soon lose 60% if their movements are restricted
What is proprioception?
Proprioception- in relation to how you move and how you sense yourself in space
Sensory input from the movable parts of the body
What caused Christina’s feelings of disembodiment?
Sensory neuritis, affecting the sensory roots of spinal and cranial nerves
Which vitamin can cause sensory neuropathies if taken in excess?
Vitamin B6
What is proprioception? What factors contribute to your sense of proprioception?
The brain receives and interprets information from multiple inputs:
-Vestibular organs in the inner ear- sends information about rotation, acceleration, and position
-Eyes- send visual info
-Stretched receptors in skin, muscles, and joints- sends information about the position of body parts
What is the motor homunculus and what does it show? How does motor information travel to the muscles?
Motor homunculus- corresponds to the precentral gyrus, represents a map of brain areas dedicated to motor processing
-Sends message to the muscles
The motor neurons release a chemical and is picked up by the muscle fiber. (sends message through spinal cord)
-This tells the muscle fiber to contract, which makes the muscles move
Many brain areas contribute to movement. How do the supplementary motor cortex, premotor area, cerebellum, parietal cortex, basal nuclei, and cerebellum contribute to movement?
Primary motor cortex- direct voluntary movement
Supplementary motor cortex (SMA) - producing sequences of movements and mental rehearsals
Premotor area (PMA) - organize motor functions before you actually do something
Cerebellum- vital for fine tuning of movements and balance
Parietal cortex- spatial visualization, transforming visual info into motor commands
Basal nuclei/ganglia- motor control, approve or reject movement signals that brain sends
What are muscle spindles and Golgi tendon organs? When do they respond? How do they contribute to reflexes? How do they contribute to proprioception?
Muscle spindles- detects stretched muscles, which activates the fibers and causes contraction to resist stretching
Golgi tendon- proprioception that prevent overstretching of muscles
-Stimulates muscle relaxation
-Sensory stuff goes in, motor stuff goes out
What is the spinocerebellar pathway? How many neurons are involved in this pathway? What type of information is contained in this pathway and where does it go? Does information from this pathway travel to the ipsilateral (same side) or contralateral (other side) side of the brain?
Spinocerebellar pathway- carries proprioceptive information to cerebellum
-2 neurons/tracts (long axons from spinal cord to brain)
-most of it is unconscious
-Does not cross over the brain and travels the same side (ipsilateral)
What is dorsal column/medial lemniscal pathway? How many neurons are involved in this pathway? What type of information is contained in this pathway and where does it go? Does information from this pathway travel to the ipsilateral (same side) or contralateral (other side) side of the brain?
Dorsal column/medial lemniscal pathway- carries sensations of two-point discrimination, proprioception, pressure, vibration to cerebrum & cerebellum via medulla
-3 neuron pathway (from brainstem to medulla)
-Crosses the brain (contralateral)
What are some treatments for Parkinson’s disease? What are some limitations of current treatments?
DBS- Deep Brain Stimulation
Dopamine agonist (L dopa)- a drug that acts like dopamine
Anticholinergics- blocks acetylcholine from being released
What is the function of GDNF? What evidence suggests that it might be a possible therapy for Parkinson’s disease? Do clinical studies support the preclinical findings?
GDNF (Glial cell Derived Neurotrophic Factor)- secreted by glial cells and is related to increasing neurotransmitter for neurons producing dopamine
-Helps promote survival of dopaminergic neurons
-Chemical that is lowered in the substantia nigra in Parkinson’s
-Clinal studies show improvement but cannot be certain
What is the function of BDNF? What evidence suggests that it might be a possible therapy for Parkinson’s disease?
BDNF (Brain Derived Neurotrophic Factor)- anti-depressant that binds to TRKB to increase dopamine and serotonin
-Binds to TRKB; tied to serotonin system
-Promotes neurogenesis, survival, and new neuron connections
What is the relationship between exercise and BDNF and GDNF? What is the relationship between serotonin and BDNF and GDNF?
-Exercise increases BDNF and GDNF
-Increases neurogenesis
-Increases number of synapses and function
-BDNF and GDNF can both influence serotonin
