Motor Cortex - Lecture 3 Flashcards
Areas of the cortex can be divided using variation in the thickness of cortical layers, what distinctive feature is in layer 5 of the motor cortex?
The upper motor neurons (Betz cells) that send descending connections straight to the spinal cord - this pattern of cortical layering identifies the motor cortex
What do Betz cells do?
They account for only 5% of the projection to spinal cord (remaining are non-Betz pyramidal cells)
They play an important role in the control of muscle activation in the distal extremities
Where do the corticobulbar tracts terminate?
In the brainstem nuceli (hypoglossal nucleus XII)
What is the area of the brain that movement can be elicited with the lowest threshold?
The motor cortex
When discussing the function of the motor cortex, what did Evens propose?
That the primary motor cortex contributes to the initial phase of recruitment of lower motor neurons
How fast do motor neurones fire and what can they code for?
Fire around 5-100ms before movement and can code for speed, direction, extent and force
Primary motor cortex neurones code for direction, what happens with movements in the opposite direction?
The firing rate of the neurone decreases
What is directional tuning?
The property of some cells to have preferred directions
What is extent, in regards to motor cortex neurones.
Extent is where some primary motor neurones fire in correlation to the distance that is moved
What did Pearce et al (2000) do?
Found that casual badminton players had a high degree of interhemispheric symmetry in the mediolateral axis. The athlete maps had a similar anterioposterior dispersion, but a significantly larger mediolateral difference.
What do experts show when watching basketball?
Temporally specific modulation of cortical excitability, at the point of ball release
