PSY100H1 Lecture Notes - Lecture 3: Neuroglia, Oligodendrocyte, Chemical Synapse
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Published on 25 Jan 2013
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Lecture 3
➢Neurons and Glia (cells that make up the brain)
Neuron (piece of tissue of the cell)
Neural membrane (skin = think of our skin) &Cytoskelelton provides the neuron's shape
(think of our bones)
Neuron membranes separate intracellular fluid from extracellular
Along this membrane is where we get changes in potential
Components : Cell body (soma), Axon, Dendrites (coming off the cell body)
Ion chanels
•ions can only go through ion chanels
•sometimes they're closed and sometimes they're open, sometimes they're specific letting
certain ions to come through and others not to come through
•different ion channels on a neuron membrane.
Phospholipid layers on neuron membrane
•studed with proteins
We have ion pumps
•difference btwn this and the channels, is that channels allow
•if you have more ions than on inside there needs to balance. Ion channels focus on
concentration inside and outside
•Pumps are different and require energy and they pump out and in against the ion
concentration.
Cytoskelelton
•3 main components used for transporting molecules that may be needed at the axon
terminals or cell body
•size is the difference btwn the components
•Microtubule (small)
•HELD in place by a molecule called Tau
•sometimes we can get a breakdown (it may disconnect from microtubule due to
phosphates?)
•Microtubules collapse and form Neurofilliary tangles = Alzheimer's Disease
•If it continues to be broken down = neuronal death
•Neurofilament (larger...transporting larger stuff)
•Microfilament (largest)
•Can transport to cell body or axon terminal
Components
Cell body (soma) contains nucleus and other organelles (phone)
Dendrites: branches that serve as locations at which info from other neurons in received
(listening to someone talk ; receive info)
•Info comes into dendritic spines (stick out of the dendrites)
•Infant with mental retardation: spines are coming out (immature)
Axon: carry neural messages to other neurons; very in diameter & length, vary on whether they
are covered in myelin or not.
•Passing on info from one cell to another (all have axons and dendrites)
•Communicate across a small gap (synapse)
•Presynaptic terminal (before the synapse) and post-synaptic