Describe the evidence for central pattern generators (CPGs) underlying the neural control of motion. Flashcards
What are Central Pattern Generators?
They are neural networks in the spinal cord capable of producing rhythmic movements when isolated from the brain and sensory inputs
Where does the evidence come from?
Mostly work on deafferented animals but some more recently on humans with spinal cord injuries.
When was the existence of spinal locotomotor CPGS in animals established?
An article called Central Pattern Generation of locomotion: a review of the evidence in 2002
How were studies performed to proved CPG on animals
Sensory feedback was removed by serving or partially serving the dorsal roots of the spinal cord - animals were still able to generate stepping movements when put on a treadmill
What does deafferented animals being able to take steps mean?
the spinal cord contains neural networks capable of generating these patterns of movement w/out the need for sensory input, indicating the presence of CPGs
What is fictive locomotion?
rhythmic motor patterns that can be observed in animals that are either immobilized or have had their sensory feedback removed, when they are stimulated either pharmacologically or electrically, closely resembling normal patterns during locomotion
What is the half-center model?
two mutually inhibitory interneurons can generate rhythmic output. When one interneuron is active, it inhibits the other and vice versa. This alternating pattern of activity can generate a rhythmic output.
Is the half-center model supported?
yes, by evidence in invertebrates which indicates it can apply to vertebrates including humans
What is the evidence of CPGs in humans?
studying humans who have had spinal cord injuries, when given body-weight support they are apple to produce rhythmic stepping movements on a treadmill
Future direction of BWS ?
studies have suggested that the use of BWS could be an important factor in retraining locomotor abilities in people with SCIs
