LONG TERM POTENTIATION AND LONG TERM DEPRESSION - Edrolo Flashcards
Long term potentiation
A process in which repeated stimulation of a synaptic connection results in the long-lasting strengthening of that synapse which means enhanced or more effective synaptic transmission.
Long term depression
Long lasting decrease in the strength of synaptic transmission, resulting from lack of stimulation of the synaptic connection.
Hebb’s rule 1949
Cells that fire together, wire together.
3 similarity and differ modes between LTP AND LTD
LTP AMOUNT Results from repeated stimulation/activation of a neural pathway whereas LTD Results from a lack of stimulation or prolonged low level stimulation of a neural pathway.
LTP EFFECT Strengthens neural pathways whereas LTD Weakens or decreases strength of neural pathways.
LTP TRANSMISSION results in Enhanced/more efficient synaptic transmission whereas LTD results in less efficient synaptic transmission .
What causes long term potentiation
An increase in the number of action potentials in a Neuron.
What occurs during long term potentiation x4
INDIVIDUAL SYNAPSE CHANGES:
Increasing amount of neurotransmitters released into the syntactic cleft. CLEFT
Increasing the number of receptors on the dendrites of post synaptic Neuron. RECEPTORS
Increasing the effect of neurotransmitters on post synaptic Neurons. I.e. Neurotransmitters are more effective even if the amount of neurotransmitters doesn’t change. EFFECTIVENESS
Increasing the sensitivity of receptors so that neurotransmitters are more effective. SENSITIVITY
A SYNAPSE CAN CHANGE USING ANY ONE OF THE ABOVE OR A COMBINATION OF THE ABOVE
What other structures can change over a long period of time in long term potentiation
Explain how x2
MORE SYNAPSES ARE PRODUCED
AXON TERMINALS AND DENDRITES
More filaments grow at axon terminals creating a greater number of terminals to release neurotransmitters. FILAMENTS
Dendrites grow dendritic spines which increases the surface area of post synaptic membranes. This means there’s more area to fit receptors in. More receptors increases the chance that neurotransmitters and receptors will bind. Therefore more chance of sending a signal. DENDRITIC SPINES
What is the main neurotransmitter involved in long term potentiation
Glutamate
What occurs during long term depression
Pre synaptic neurons produce and release less neurotransmitters NEUROTRANSMITTERS
Receptors on dendrites reduce in number RECEPTORS
Post synaptic neurons become less sensitive to neurotransmitters that do happen to be released. SENSITIVITY
What causes long term depression
When action potentials are not generated.
Importance of LTD
Important to reduce unnecessary synapses to conserve resources and allow necessary synapses to be created.
