Neurotransmission and treatments for depression Flashcards
Communication in the brain
What are different cells of the nervous system?
Neurons and Glial cells
What percentage of the volume do Glial cells make up of the CNS?
50%
What function do the Glial cells have in the CNS?
Maintenance of synapses through the production of myelin and provide nourishment for the neurons
What are the three major structures of the Neuron?
Cell body, Dendrites, Myelin sheath
What is in the Neuron cell body?
Contains all of the organelles which maintain the cell, includes the nucleus (contains all of the genetic material)
What is the function of the cell body?
Relays signals down to the axon
What is the structure of dendrite?
Thin, bushy like structures, specialised projections that can receive signals from neighbouring neurons
What are the functions of the dendrites?
Receiving signals from neighbouring neurons and relaying information into the cell body
What is the structure of the myelin sheath?
80% lipids (fats) and 20% proteins
What is the function of the myelin sheath?
Insulating the neurons so that electrical signals are not lost
What makes the myelin sheath?
Oligodendrocytes in the CNS
What does gray matter mostly consist of?
Neuronal cell bodies
What does white matter mostly consist of?
myelinated axons
Where are neuronal cell bodies most abundant?
Cerebrum, brain stem and cerebellum
What percentage of the brain volume does the cerebellum make up?
10%
What is special about the cerebellum?
It contains more neurons than the rest of the brain put together
Where is gray matter usually found?
Gray matter is usually found surrounding white matter in the external areas of the brain
What does the term nuclei refer to?
The regions of gray matter that are located in deeper regions of the brain
In the cerebrum and cerebellum where is white matter more likely to be found?
Predominantly found in deeper areas
What are other gray matter structures?
Basal ganglia
In what is the basal ganglia embedded in?
In white matter
In which case is the gray matter is embedded into the white matter?
In the spinal cord <3
Are neuron electrically excitable?
Yes
What concentration of ions differ from the inside the cells?
Sodium (NA+) and potassium (K+)
Which elements start off outside the cell?
Sodium
What causes the ions to continuously move down the concentration gradient?
The concentration differences cause ions to continuously move down the concentration gradient through ion channels that are high permeable
Which ion is the channel highly permeable to?
Potassium (K+)
If the movement stops with the inside of the cell what will be the resting potential of the cell?
-70mV
What is an action potential?
A short term change in the electrical potential that travels along a cell it releases the neurotransmitter into the synaptic cleft
What is the resting potential?
Is what happens when a neurons is at rest
What is an action potential is caused by?
Different ions crossing the neuron membrane resulting in the neuron sending information down the axon, away from the cell body
What is an action potential?
An explosion of electrical activity that is created by a depolarising current
How many steps can the formation of action potential be divided into?
five steps