NEUR 3144 Exam 02

What are theta sequences?

Compressed sequences of place cells where the past, present, and future is encoded in a single cycle that is produced from phase procession.

True or False: Epinephrine can cross the blood brain barrier

False

True or False: The Morris Water Maze tests the animals memory of fearful stimuli.

False

What were the challenges that Marian faced in her career?

Gender discrimination (male-dominated field), new ideas that have never been proposed before

Describe a specific test that neuroscientists use to assess learning and memory in rodents.

INHIBITORY AVOIDANCE CONDITIONING: 2 sides of the box where the rodents like the dark were shocked when they go to the dark side. The time they take to go to the dark side is the measurement: a longer latency is better learning and memory FEAR CONDITIONING: In fear conditioning, after the rat has explored the conditioning context, an auditory cue (tone) is presented for about 15 seconds. Shock is delivered when the tone terminates. Rats are then tested for their fear of the context-place where shock occurred and later for their fear of the tone. Shocked rats display more freezing than rats that were not shocked MORRIS WATER MAZE: rodents are placed in a pool of water with an escape platform. They eventually learn where the platform is and the time they take to get to the platform is measured. A shorter latency is better learning and memory.

How were the roles of NMDA and AMPA receptors, and CaMKII (important for LTP) shown to be important for memory?

If you knock out NMDA by blocking a subunit via APV, no learning will occur. If you knock out AMPA by blocking it with CNQX, no learning and no memory retrieval. If you knock out CaMKII as a whole or knockout just autophosphorylation, no learning will occur.

How was it demonstrated that the autophosphorylation ability of CaMKII is important for memory?

If you were to knock out CamKII as a whole or just autophosphorylation, no learning will occur . No learning=no memories formed so therefore CaMKII is important for memory.

How are local field potentials generated?

Local Field Potentials are generated by currents going in and out of the cell all the time which gives it such a complex shape. If you don't give a rate a reward for completing a task after a specific amount of time the hippocampal cells of the subject will start to function to code for the time instead of the space in which they are in.

What is the relationship between consolidation and stability of memories?

Memories become more stable the longer they are consolidated Disrupting sharp-wave ripples degrades memory consolidation Memories are transferred from the hippocampus to the cortex and are less likely to be disrupted

What is the difference between rate- and temporal-coding?

RATE CODING is counting the number of spikes that occurred in the stimulus. TEMPORAL CODING is the importance of the time between the onset of the stimulus and the spikes.

What is replay?

Replay is what happens in the hippocampus when all the cells throughout a map are compressed into one after the animal is done navigating and getting something good at the end, like a reward, so that it can remember how to get there and the cells are just once or twice in a small sequence called a "sharp wave ripple oscillation."

What are two ways that memories can fail?

Storage failure Retrieval failure

What is one way that THC decreases memory performance?

THC lowers theta power and therefore leads to less theta oscillations, it lowers the amplitude of the sign wave. Agonist of receptor; less coordinated activity of theta when THC is being injected Less neuronal coordination and less theta oscillations; less organized

What were Marian's major contributions to science?

The introduction of the concept of brain plasticity and the importance of enrichment on the mind and brain.

What role does the BLA nucleus of the amygdala play in memory?

The locus coeruleus releases norepinephrine in the BLA and this improves your memory. When norepinephrine was injected into the BLA there was improved memory and when it was blocked, memory worsened.

How can neuroscientists intervene in brain function to test memory mechanisms?

There are many ways in which neuroscientists can intervene in brain function to test memory mechanisms. Stereotaxic surgery which you remove the scalp and use the fissions as landmarks to inject a virus or drug in the brain Transgenic animals Optogenetics which use light to control your neural activity Viral gene expression modification which injects nonreplicating viruses and has the cell transcribe/encode the proteins for it.

True or False: An example of temporal coding is the phase of action potential spiking in relation to an ongoing oscillation (i.e. theta)

True

True or False: Blocking AMPA receptors prevents both acquisition and retrieval of memories

True

True or False: Disrupting sharp-wave ripples degrades memory consolidation

True

True or False: Increased norepinephrine in the amygdala improves memory.

True

True or False: Local field potentials are generated by transmembrane currents flowing in and out of neurons

True

True or False: Memories become more stable the longer they are consolidated.

True

True or False: THC decreases memory performance by degrading the theta oscillation

True

True or False: Theta oscillations occur when a rodent is awake and running.

True

What local field potential oscillations are prominent during wake, REM sleep and slow wave sleep?

WAKE: theta oscillations REM SLEEP: theta oscillations SLOW WAVE SLEEP: sharp wave ripples