Neurobiological Pathways and Circuits involved in Motor Control (ALS/MND) Flashcards
Role of upper motor neurons in motor execution?
Executing voluntary movements
How are upper motor neurons involved in executing voluntary movements?
They transmit signals to lower motor neurons–> ensures precise muscle activation and coordination during complex motor tasks
How is sensory feedback integrated into motor action?
Upper and lower motor neurons integrate sensory feedback with motor commands
What is a neural circuit?
A network of interconnected neurons that process specific types of information to carry out particular functions when activated
Neural circuit components?
Receptor in skin–> afferent nerve–> SC–> efferent nerve–> effector organ
Main roles of neural circuits?
Information processing, adapting to new experiences, coordination of complex behaviours
Which type of organs take input in a neural circuit?
Sensory organs
Which type of neurons are responsible for output in neural circuits?
Effector organs
What is a neural pathway?
A series of connected neurons that transmit signals from one part of the nervous system to another
Two kinds of tracts in neural pathways?
Pyramidal tracts and extrapyramidal tracts
Where do pyramidal and extrapyramidal tracts transmit motor commands from?
Brain
Where do pyramidal and extrapyramidal tracts transmit motor commands to (directly and also ultimately)?
Spinal cord, eventually to muscles
Difference in structure between neural circuits and neural pathways?
Neural circutis involve multiple layers of neurons with feedback loops while neural pathways are more linear
Difference between neural circuits and neural pathways in terms of self regulation?
Neural circuits have feedback loops whereas neural pathways dont
What do feedback loops in neural circuits allow for?
Dynamic interactions and adjustments based on inputs
Difference between neural circuits and neural pathways in terms of what is done with/to the data?
Neural circuits are involved in processing the data whereas neural pathways are involved in transmitting signals without processing
Difference in specificity between neural circuits and neural pathways?
Neural circuits are specialised for a task (reflexes etc) whereas neural pathways are not dedicated to specific tasks, and instead serve broader functions
Difference between neural circuits and neural pathways in the symptoms that occur as a result of damage to them?
Neural circuit dysfunction leads to neurological disorders whereas neural pathway damage can lead to sensory deficits
Examples of neurological disorders that can come about as a result of neural circuit dysfunction?
Huntingtons and Parkinsons
Efferent pathway in motor control directiom?
Travels from the brain, through the motor neurons, to the descending portions and then the lower motor neurons transmit the commands to the effector organs
What kind of tract is responsible for voluntary movements?
Pyramidal tract
Where does the pyramidal tract begin and end?
Begins in the cortex, ends in the spinal cord
What are the two types of pyramidal tracts?
Lateral corticospinal tract and anterior corticospinal tract
What are the different extrapyramidal tracts?
Rubrospinal, reticulospinal, olivospinal, vestibulospinal
What kind of tract is responsible for involuntary movements?
extrapyramidal
What are the two main classes of descending pathways (tracts)?
Pyramidal and extrapyramidal
What are the main ascending pathways?
Dorsal column medial lemniscus system, spinocerebellar tracts, anterolateral system
Where does the anterolateral system run from and to?
SC to thalamus
Four types of neural citcuit?
Local circuit, upper motor neurons circuit, cerebellum, basal ganglia
What is in the local circuits?
Consist of the SC (especially grey matter), lower motor neurons, local circuit neurons
Where does the upper motor neurons circuit run from and to?
From the brain to the SC
Main functions of local circuits?
Coordination of the reflex action, and basic control–> coordinates movements related w/ SC
Which pathway do local circuits use?
Spinal reflex pathways and descending pathways from upper motor neurons
Which diseases are associated with local circuit dysfunction?
MS, Cervical spondylotic myelopathy, traumatic SC injury
