Final Flashcards
What is short term memory?
Memory occurring for a few seconds or minutes and used for comprehending, reasoning, or problem solving.
AKA: working memory
Ex: listening, note taking, reading, recalling a phone number
What is long term memory?
Memory of the past. There is no limit to how much LTM can be stored nor on how long they last. (some may last a life time)
Ex: remembering when you went to Niagara Falls as a small child
What is declarative memory?
Memory of general facts, concepts, and knowledge as well as personal memory of events of the past.
Refer to ‘what’
Ex: remembering your 5th birthday party or that a whale is a mammal
What is non-declarative memory?
Memory of skills such as motor, cognitive, and perceptual skills.
Refer to ‘how’ to do something
Ex: recalling how to ride a bike or add numbers
What is long term potentiation (LTP)?
Strengthening of the effect of a presynaptic input on a postsynaptic cell, causing the synapse to be used in a particular way.
The excitatory synaptic response of the postsynaptic neuron is increased.
The effect can last for weeks, months, or years
How is LTP selective?
The size of the post-synaptic cell’s response is unaffected to inputs that are inactive during high frequency stimulation or input
How is LTP associative?
Inputs of the cell that were activated at high frequency of action potentials are potentiated while activated inputs to the cell are associated.
This is an essential process for associative learning.
What 2 events have to happen at the synapse for LTP to occur?
AMPA receptors are bound by glutamate and the cell membrane is depolarized to -35mV or less
Depolarization removes blockage of calcium channels by magnesium and the NMDA receptor can respond to glutamate while calcium enters the postsynaptic cell. Increasing levels of calcium activate 2 protein kinases.
What are the kinds of neural restructuring that occur in the pre- and post-synaptic neurons after LTP has occurred?
- The release of the neurotransmitter from the presynaptic neuron is enhanced so next time it is excited, more neurotransmitter will be released.
- The postsynaptic neuron makes more glutamate receptors to be more responsive in the future
- EPSPs are increased or more likely in the future due to the glutamate receptor of the postsynaptic neuron being more responsive
Label all of the structures, pathways, and synapses on the drawing of the hippocampus (20pts)
See Drawing
Define ischemic stroke and how common they are
There is a low oxygen state due to decreased blood flow or obstruction
85% of all strokes
How do ischemic strokes cause damage?
Damage is caused by death of neurons and glia because of loss of oxygen and changes in pH and cell membranes, which results in release of glutamate and opening of calcium channels to be prolonged. This allows toxic levels of calcium to enter the cell and can result in proteins that can be harmful to the cell to be produced and cause tissues to become inflamed and swollen.
What are the different subtypes of ischemic strokes?
Atherosclerotic thrombosis: hardening or narrowing of arteries due to collections of platelets, fibrin, etc or blood clot resulting in partial or complete blockage (forms onsite).
Cerebral embolism: blockage of an artery by clot or other material that has been brought to that area by blood flow (forms elsewhere in body travel to site).
Lacunae: occlusion of small cerebral arteries
TIA: transient lack of oxygen that does not lead to permanent neurological damage
What are the 6 ways/reasons why lost function returns or can return?
- Compensation compared with recovery: people may not actually recover their lost functions but develop new ways to function
- Part of the of the recovery is due to recovery from diaschisis (part of loss of function was due to neurons being temporarily shocked so when they recover they make new connections and regain function)
- Denervation super-sensitivity is another part of recovery in which the brain tries to maintain homeostasis by making more receptors to compensate for the loss of neurons and neurotransmitters. The increase in receptors can only partially compensate for the loss.
- Rehabilitative treatment can result in a lot of recovery. Therapy forces people to use their affected limb for regaining function. Sometimes this can result in a full function recovery
- Amphetamines increase the blood flow to the area of the brain that is being used for a particular task and stimulates growth factors to allow synaptogenesis and leads to increased function.
- Stem cells that secrete a nerve growth factor have been shown to improve function (in animals) and my be a therapy of the future
