Neural Basis of Movement: Lecture 1
• Learning objectives :
• You should be comfortable with the following concepts:
– the operation of nerves & synapses
– What the neuromuscular junction is & does
– methods to measure nerve/brain activity
– localization of brain function
Why do animals have a nervous system…for adaptive behaviour.
“Memory, cognition, sensory processing, they’re there for a reason, and that reason is
action” (Wolpert, 2010)
Nerves
- nervous system supports movement
• Nerves are cells that are specialized for communication over distances
• Neurons are specialised to communicate across long differences Neurons
interconnect with synapses (the connection between one nerve cell and the
another = synapse)
• Synapses are specialized for integration and modulation of signals
• Changes in synapses underlie learning and memory
Neuron types
Simple to
complex
All nerve
have a cell
body,
nucleus,
dendrites
(receive
info), axon
(sending
out signals,
terminal
dendrites
(sharing info out with what its connected to) Input side and output side
, Neuronal Processing
o The nematode worm Caenorhabditis elegans has exactly 302 neurons.
Scientists have mapped all the neurons & connections.
o The fruit fly Drosophila melanogaster has ~ 300,000 neurons. Scientists
cannot yet get close to knowing all the cell connections for this animal.
o The human brain at ~ 100 billion (1011) neurons and 100 trillion (1014)
synapses …100,000,000,000,000
Nerves send signals along their branches by changing membrane potential
*Neurons are specialised cells, and have a cell membrane the membrane is
reasonably insulating for activity, the fluid inside the neuron conducts the electricity
Currents can flow in and down the branches on the neuron
Neurons have learnt that they can change their membrane voltage, which causes a
current to flow down the branch to the other end (read signal)
“local” potentials
• Changes in membrane voltage (signals neurons use, change in voltage
between inside and outside of the membrane)
Communicate by allowing voltages to change
• Measured as potential difference across membrane
• Cannot transmit signals any long distance
• Due to lack of insulation, a lot of the signal gets lost
Change of membrane voltage by change of membrane permeability. This is
initiated by…
1. Sensory receptors
2. Post-synaptic receptors
• Learning objectives :
• You should be comfortable with the following concepts:
– the operation of nerves & synapses
– What the neuromuscular junction is & does
– methods to measure nerve/brain activity
– localization of brain function
Why do animals have a nervous system…for adaptive behaviour.
“Memory, cognition, sensory processing, they’re there for a reason, and that reason is
action” (Wolpert, 2010)
Nerves
- nervous system supports movement
• Nerves are cells that are specialized for communication over distances
• Neurons are specialised to communicate across long differences Neurons
interconnect with synapses (the connection between one nerve cell and the
another = synapse)
• Synapses are specialized for integration and modulation of signals
• Changes in synapses underlie learning and memory
Neuron types
Simple to
complex
All nerve
have a cell
body,
nucleus,
dendrites
(receive
info), axon
(sending
out signals,
terminal
dendrites
(sharing info out with what its connected to) Input side and output side
, Neuronal Processing
o The nematode worm Caenorhabditis elegans has exactly 302 neurons.
Scientists have mapped all the neurons & connections.
o The fruit fly Drosophila melanogaster has ~ 300,000 neurons. Scientists
cannot yet get close to knowing all the cell connections for this animal.
o The human brain at ~ 100 billion (1011) neurons and 100 trillion (1014)
synapses …100,000,000,000,000
Nerves send signals along their branches by changing membrane potential
*Neurons are specialised cells, and have a cell membrane the membrane is
reasonably insulating for activity, the fluid inside the neuron conducts the electricity
Currents can flow in and down the branches on the neuron
Neurons have learnt that they can change their membrane voltage, which causes a
current to flow down the branch to the other end (read signal)
“local” potentials
• Changes in membrane voltage (signals neurons use, change in voltage
between inside and outside of the membrane)
Communicate by allowing voltages to change
• Measured as potential difference across membrane
• Cannot transmit signals any long distance
• Due to lack of insulation, a lot of the signal gets lost
Change of membrane voltage by change of membrane permeability. This is
initiated by…
1. Sensory receptors
2. Post-synaptic receptors
