Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
87 Cards in this Set
- Front
- Back
|
anterograde amnesia
|
-an impairment in forming new memories
|
|
|
retrograde amnesia
|
the inability to remember events prior to impairment
|
|
|
what makes up the medial temporal lobe
|
hippocampus and the amygdala
|
|
|
CA1
|
provides the primary output from the hippocampus to other brain areas; damage in that part of both hippocampi results in moderate anterograde amnesia and only minimal retrograde amnesia
|
|
|
what happens if your entire hippocampus formation is damaged?
|
results in retrograde amnesia extending back 15 years or more
|
|
|
consolidation
|
-is the process of making short term memories into long term memories
-requires the hippocampus and time -occurs best during sleep |
|
|
retrieval
|
-is the process of accessing stored memories, the act of remembering
-the hippocampus is involved in retrieving memories |
|
|
two types of memory
|
-short term memory
-long term memory (it can be split up into to categories: hours to months and Months to lifetime) |
|
|
what plays a leading role in consolidation?
|
hippocampal formation
|
|
|
rat study with water maze
|
-this experiment shows two things: glutamate is involved in consolidation and blocking consolidation interferes with making long term memories
-the rats learned to escape the maze -right after their successful learning, during the time of consolidation the rats' hippocampi were administered drug that blocked glutamate receptors -when retested (after the glutamate receptor blocker was cleared from their body) the rats did poorly on the maze |
|
|
role of prefrontal cortex in memory
|
-active during retrieval
-active during working memory the more difficult the task the larger the area of recruitment of the prefrontal cortex (instead of left only, right and left are recruited) |
|
|
long term memories are created by...
|
interaction of the hippocampus with different areas of the cerebral cortex
|
|
|
long term memories are probably stored in the areas that ___
|
different memories are located in different cortical areas, apparently according to where the information they are based on was processed.
|
|
|
two categories of memory processing
|
1. declarative memory
2. nondeclarative memory |
|
|
declarative memory
|
-involves learning that results in memories of facts, people and events which a person can verbalize or declare.
-includes episodic memory (events), factual memory (facts), autobiographical memory (info about oneself) and spatial memory (location of the individual and of objects in space) |
|
|
nondeclarative memory
|
-involves memories for behaviors; these memories result from procedural or skills learning (involves the striatum), emotional learning (involves the amygdala) and stimulus response conditioning
|
|
|
working memory
|
-provides a temporary "register" for information while it is being used
-holds a phone number you just looked up or that you recall from memory, while you dial the number; it is also used for problem solving and decision making -similar to RAM |
|
|
During a delayed match to sample task specific neurons in the ____ are active
|
prefrontal cortex
-neurons here fire even during a distracting stimulus -dopamine is involved becuase when dopamine blockers are injected working memory is blocked -the prefrontal cortex is also involved in making executive decisions "it manages certain kinds of behavioral strategies and decision making and coordinates activity in the brain areas involved in the perception and response functions of a task, all the while directing the neural traffic in working memory -neurons in association areas of the parietal cortex and temporal lobes are also active |
|
|
learning is a form of ____ that changes behavior by remodeling neural connections.
|
neural plasticity
|
|
|
Hebb Rule
|
-If an axon of a presynaptic neuron is active while the postsynaptic neuron is firing, the synapse between the will be strengthened
|
|
|
Long term potentiation (LTP)
|
-is an increase in synaptic strength following repeated high frequency stimulation.
-it is the best candidate for explaining the neural changes that occur during learning -it can last for anywhere from minutes to a few months -it occurs in the hippocampus, visual, auditory, and motor cortex |
|
|
What does the researcher do before inducing LTP?
|
-the researcher excites a group of neurons with a brief electrical pulse and measures the response in the postsynaptic neurons as an index of baseline activity.
|
|
|
what happens after LTP is induced?
|
-the LTP is induced by stimulating the presynaptic neurons with several high frequency pulses of electricity over a period of one to several seconds.
-a brief pulse of stimulation is again applied as a test; this time the postsynaptic neurons produce a larger excitatory potential |
|
|
long-term depression (LTD)
|
-is a decrease in the strength of a synapse that occurs when an axon of a neuron is active while the postsynaptic neuron is not polarized
-is possibly the mechanism the brain uses to clear the hippocampal area of old memories, to make room for new information |
|
|
What happens without LTD?
|
presumably a potentiated synapse would remain so and could not be modified to take part in new associations
|
|
|
associative long term potentiation
|
an effect caused when a synapse is stimulated weakly while another synapse on the same postsynaptic neuron is being stimulated strongly, the "weak" synapse as well as the "strong" synapse will be potentiated
|
|
|
potentiation
|
the increase in strength of nerve impulses along pathways that have been used previously either short term or long term
|
|
|
strong and weak synapses can be produced in isolated brain tissue by stimulating the _____ with different intensities of electricity, but they are produced naturally by _____
|
presynaptic neurons
experience |
|
|
in nature, ____ is more likely to occur because a neuron is firing out of synchrony with other neurons___
|
LTD
|
|
|
Associative long-term depression
|
is the weakening of a synapse that is active when the postsynaptic neuron is not depolarized and that is inactive when the postsynaptic neuron is depolarized
|
|
|
Theta rhythm
|
is EEG activity with a frequency range of 3 to 7 Hz.
-this is used to induce potentiation and depression more quickly-- used in hippocampus -typically occurs in hippocampus when an animal is learning something -believe that theta rhythm, by responding to novel situations (learning), may emphasize important stimuli for the brain and facilitate LTP and LTD -eliminating theta rhythm can interfere with learning |
|
|
double alternation task
|
-requires animals to turn the opposite way on alternate trails in a two choice maze to obtain food; having to remember the previous turn places a demand on working memory
-suppressing hipocampal theta with anesthetic or sedative drugs eliminates rats' ability to perform this task -it suggests that theta is necessary for the formation of at least some types of memory |
|
|
in nature, ____ is more likely to occur because a neuron is firing out of synchrony with other neurons___
|
LTD
|
|
|
Associative long-term depression
|
is the weakening of a synapse that is active when the postsynaptic neuron is not depolarized and that is inactive when the postsynaptic neuron is depolarized
|
|
|
Theta rhythm
|
is EEG activity with a frequency range of 3 to 7 Hz.
-this is used to induce potentiation and depression more quickly-- used in hippocampus -typically occurs in hippocampus when an animal is learning something -believe that theta rhythm, by responding to novel situations (learning), may emphasize important stimuli for the brain and facilitate LTP and LTD -eliminating theta rhythm can interfere with learning |
|
|
double alternation task
|
-requires animals to turn the opposite way on alternate trails in a two choice maze to obtain food; having to remember the previous turn places a demand on working memory
-suppressing hipocampal theta with anesthetic or sedative drugs eliminates rats' ability to perform this task -it suggests that theta is necessary for the formation of at least some types of memory |
|
|
During LTP, synaptic changes include:
|
increased neurotransmitter release, increased receptor sensitivity, and structural changes in the synapse
|
|
|
when adjusting neurotransmitter release, some sort of feedback from the post synaptic neuron is required, what messenger is used?
|
nitric oxide
|
|
|
when the postsynaptic neuron is activated, it releases nitric oxide gas into the ____
|
synaptic cleft
-the nitric oxide diffuses back across the cleft to the presynaptic neuron, where it induces the neuron to release more neurotransmitter -if the synthesis of nitric oxide is blocked chemically, LTP does not occur -nitric oxide lasts only briefly, but the increase in neurotransmitter release is long term. |
|
|
in most locations, the neurotransmitter involved in LTp is___
|
glutamate
|
|
|
two types of glutamate receptors involved in LTP
|
AMPA receptor
NMDA receptor |
|
|
Initially, glutamate activates AMPA receptors but not NMDA receptors. Why?
|
Because NMDA is blocked by magnesium ions.
|
|
|
During LTP induction, activation of the AMPA receptors by the first few pulses of stimulation ___
|
-partially depolarizes the membrane, which displaces the magnesium ions
-the critical NMDA receptor can then be activated, resulting in an influx of sodium and calcium ions; not only does this further depolarize the neuron, but the calcium activates CaMKII (enzyme that is necessary for LTP) |
|
|
CaMKII
|
-an enzyme that is necessary for LTP
-apparently functions as a binary (two way) switch that changes the strength of a synapse. |
|
|
The final stage of LTp involves:
|
-alteration of gene activity and synthesis of proteins
-these changes are responsible for structural modifications in the dendrites that produce longer lasting increases in the synaptic strength |
|
|
within 30 minutes after LTp, postsynaptic neurons develop increased number of ___
|
dendrite spines, outgrowths from the dendrites that partially bridge the synaptic cleft and make the synapse more sensitive
|
|
|
is there an increase in the volume of the brain areas that are involved in LTP
|
-yes!
-research done on cab drivers- MRI scans on the posterior part of their hippocampi known to be involved in spacial navigation, was larger than in males of similar males |
|
|
When researchers used genetic manipulation to decrease the number of NMDA receptors in mice, what happened?
|
LTP in the hippocampus was reduced and the there was impaired learning in the water maze
|
|
|
improving LTP, enhances ____
|
learning!
|
|
|
How can you increase LTP?
|
with ampakines
-compounds that increase the time AMPA receptors are open |
|
|
2 features that make neural network a good storer of learned information
|
-one single network can hold a lot of different sets of information
-because information is distributed throughout the network, and is relatively immune to damage |
|
|
both excitation and inhibition are required to form ___
|
functioning neural networks
|
|
|
a problem with explaining that LTP is involved in learning
|
in the laboratory, LTP has a limited life span while some memories last a lifetime
|
|
|
Short term memory involves changing:
|
the strengths of connections at already existing synapses, an effect that lasts for periods of seconds to hours
|
|
|
long term memory involves gene:
|
activation, gene silencing, and synthesis of proteins that support the growth of new connections
|
|
|
for declarative memories, long term memory consists of a stage that takes place in the ____, followed by a transition to a more ____
|
medial temporal lobe
permanent form in the cortex |
|
|
NMDA receptors are essential to ___ and ___
|
LTP and learning
|
|
|
block NMDA receptors =
|
no learning
|
|
|
genetically create mice with fewer NMDA receptors than normal mice =
|
more difficulty learning
|
|
|
ampakines
|
-drugs that increase the time that AMPA receptors are open
-these cause increased LTP and increased behavioral performance in learning tasks |
|
|
Inhibiting CAMKII blocks the development of ___, but does not reverse ___ once the synaptic changes have occurred
|
LTP
LTP |
|
|
Inhibiting another protein _____ "causes amnesia for an established conditioned response
|
kinase (protein kinase M zeta)
|
|
|
One theory for consolidation is that the hippocampus transfers...
|
information to the cortex during times when the hippocampus is less occupied -- for example, during sleep"
|
|
|
extinction
|
-memories are not lost, extinction involves learning that the stimulus does not need to be attended
-if LTP is blocked the extinction phenomenon is also blocked |
|
|
forgetting
|
-protein phosphatase 1 (PP1) removes phosphates from proteins that were activated by adding phosphates.
-useless information to prevent the saturation of synapses with information that is not called up regularly or has not made connections with other stored memories |
|
|
reconsolidation
|
-occurs any time a memory is recalled
-requires synthesis of new proteins -Apparently, reopening a memory provides the opportunity to refine it, correct errors, and modify your emotion response -memories get reconstructed over time (false information can be inserted during the reconsolidation time) |
|
|
is losing memory inevitable as you become older?
|
-no!
-cognitive skill training produces significant and enduring improvement in the elderly -Rats raised in an enriched environment or even old rats have more dendrites and synapses per neuron in the cortex -although nerve cells are lost daily, the number of synapses increases with age (with age comes wisdom) - |
|
|
loss of neurons in the ____has been correlated with cognitive deficits in humans
|
basal forebrain
-the neurons that interact in the basal forebrain also interact with the hippocampus, amygdala, and cerebral cortex |
|
|
Alzheimer's Disease
|
-a disorder characterized by progressive brain deterioration and impaired memory and other mental abilities
- problems with declarative/explicit memory -trouble remembering recent events, forgets names, has word-retrieval problems -problems with language, visual-spatial functioning, reasoning |
|
|
plaques
|
-are clumps of amyloid, a type of protein, that luster among axon terminals and interfere with neural transmission
- |
|
|
Ab42 amyloid
|
s insoluble and clumps easily and is the predominant form of the protein found in plaques
|
|
|
amyloid
|
is deposited outside cells in normal individuals, but doesn't build up the way it does in those with Alzheimer's disorder. The protein is Ab40 amyloid protein which is also insoluble in non-Alzheimer's individuals
|
|
|
The____ and___ compromise function of hippocampal neurons resulting in problems with the formation of new long term memories.
|
The tangles and plaques
|
|
|
ADDL
|
a form of amyloid that is soluble attaches to dendrites and compromises their function
|
|
|
Neurofibrillary tangles
|
(composed of tau protein, involved in neuron cytoskeletons) accumulate within neurons of individuals with Alzheimer's and is associated with the death of brain cells
|
|
|
Alzheimer's and heredity
|
-mutations in the amyloid precursor protein gene (APP gene) are involved
-mice with a mutation in the APP gene that increased the number of plaques had deficits in spatial learning and LTP -Other genes associated with Alzheimer's also affect amyloid production or its accumulation outside of nerve cells: presenilin 1, presenilin 2, and ApoE4 -there may be as many as 100 different genes involved in the creation and progression of this disease. |
|
|
Alzheimer's Disease- acetylcholine
|
-releasing neurons in the brain "are the victims of degeneration in Alzheimer's disease" (p 383)
|
|
|
Treatment of Alzheimer's Disease
|
-treatments have involved increasing and/or restoring function of acetylcholine-producing neurons
-nvolve preventing the breakdown of acetylcholine at synapses and help before the degeneration is advanced. |
|
|
Treatment of Alzheimer's Disease: memantine
|
-limits neurons' sensitivity to glutmate
-glutamate excitotoxicity occurs (over activation of NMDA receptors which causes large amounts of calcium to build up within these overstimulated neurons) -glutamate excitotoxicity causes neuron death |
|
|
Treatment of Alzheimer's Disease: other drugs that may help other than memantine
|
anticholesterol drugs and nonsteroidal anti-inflammatory drugs (related to prostaglandins, which interact with prostaglandin receptors) may also help
-estrogen treatment in older women may preserve the density of dendritic spines (as in rats) |
|
|
Treatment of Alzheimer's Disease: in future may focus on increasing the formation of new neurons within the brain, especially in the ___
|
Hippocampus
|
|
|
Treatment of Alzheimer's Disease:in the future genes for nerve growth factor NGF:
|
NGF, which is important in stimulating neuronal growth during development- may be engineered into neurons that are then injected into brains.
|
|
|
Korsakoff's syndrome
|
-degeneration associated with chronic alcoholism due to a deficiency in vitamin B1, thiamine.
-anterograde amnesia with impairment in declarative/explicit memory - |
|
|
Korsakoff's syndrome Characteristics
|
-confabulation: making up stories to compensate for their memory loss
-abnormal activity in the frontal lobes |
|
|
Annual direct cost of Alzheimer disease and dementia
|
~$156 billion worldwide
|
|
|
Mice genetically engineered with a gene that usually causes amyloid deposits to appear in these mice.
|
-Some were given "access to stimulating toys and exercise equipment" and they had fewer amyloid deposits that those that were not in the stimulating environment.
-The actively-stimulated mice also had higher levels of an enzyme which breaks apart amyloid -and several genes associated with learning, neurogenesis, and cell survival had been upregulated" |
|
|
the function of the hippocampal formation is
|
-consolidation of new memories
-retrieval of memories -as a temporary storage location |
