Lecture 3: Biological Basics Flashcards
What is the Phineas Gage case-study?
Man lost part of his brain. His personality changed and it changed his ability to plan.
What are neurones?
- building blocks of the brain
- 100 billion when born
- lose 10,000 a day
- connects to 50,000 other neurons
What are sensory neurones?
- help recode information.
- transmit to spinal cord/brain.
- outside world —–> signal
What are interneurons?
- simply ‘pass it along’.
- neurons that communicate with other neurons.
What are motor neurones?
-responsible for transmitting messages from CNS to muscles.
What are Glial cells?
- 10 to 1 neuron.
- waste disposal + axon protection
- learning + memory.
What are the different parts of a neurone?
- Dendrites
- Soma
- Axon
- Axon terminal/terminal button
- Synapse
What is the role of the dendrites?
-Absorb chemical information/stimulation from other neurones.
What is the role of the soma?
-If dendric activity large enough, an electric action potential fired.
What is the role of the axon?
-Conducts electrical signal to terminal buttons at the end of the axon.
What is the role of the axon terminal/terminal button?
-Electrical signal ——–> chemical squirt
What is the role of the synapse?
-Jump chemical has to make to be taken up by the next dendrite.
How can we observe individual action potentials?
Attach micro-electrodes to axons.
What is the charge of a resting neurone?
Around -70mV.
What is the stage of + charge (+40 action potential)?
Depolarization.
What is the stage of - charge?
Repolarization.
What charge does a neurone have in the refractory period?
Overcompensates resulting in - charge.
How long does it take for a neurone to return to resting state?
5 minutes (200Hz).
Are neurones all the same?
No. Different neurones have different responsibilities. Yet all the neurones work together.
How are differences in sensory environment coded?
By changes in the rate of axon firing or by the magnitude of neurone firing.
What are the three type of feature detectors?
1) Simple cells.
2) Complex cells.
3) End-stopped cells.
What do simple cells do?
Respond to size, orientation and colour.
What do complex cells do?
Respond to orientation and direction.
What do end-stopped cells do?
Respond to orientation, direction and size.
What does it mean if a neurotransmitter is inhibitory?
Firing rate hyperpolarization.
What does it mean if a neurotransmitter is excitatory?
Firing rate depolarization.