Learning & Memory

Question 1

NMDA receptors only open when:

they act as:

Answer 1

there is high frequency activity therefore a lot of glutamate. It acts as a coincidence detector

Question 2

What is associativity in LTP?

Answer 2

neuron synapses neighboring neurons that are stimulated by high frequency activity are also strengthened. ex: details you remember about an event, like clothes people were wearing when something happened.

Question 3

What is the significance of CAM-Kinase 2:

Answer 3

phosphorylates subunit in AMPA receptor to increase conductance through channel> more ions/second enter > increased strength of synapse. also tags other proteins in activated synapse to “flag” more AMPA receptors to be inserted.

Question 4

Long term depression plays a role in:

Answer 4

motor learning, hippocampus declarative learning

Question 5

How does LTD work?

Answer 5

low influx of calcium activates phosphatases, causes AMPA retrieval (opposite of insertion)

Question 6

how do glucocorticoids affect LTP?

Answer 6

impairs LTP (high levels)

Question 7

In Huntington’s disease, which specific neurons are affected?

Answer 7

medium spiny neurons in caudate and putamen

Question 8

the genetic basis of Huntington’s is:

Answer 8

increased number of trinucleotide repeats. specifically: CAG repeat, puts long stretch of glutamines on Huntington’s protein = “sticky”, interferes with gene expression by binding transcription factors

Question 9

expanded glutamine repeats cause Huntington’s via:

Answer 9

interfering with gene expression
gumming up protease system = protein accumulation
fragments of proteins cause toxic effect
affect axonal transport, esp retrogade transport of factors needed for neuronal survival
mitochondrial/energetic problems

Question 10

what is the cellular basis of Alzheimer’s?

Answer 10

1. elevated phosphorylation of Tau proteins in microtubules> loss of adherence to microtubules > mt start unraveling;
2. amyloid precursor protein APP cleaved by beta-gamma secretases > toxic peptide forming fibril formation > amyloid plaque

Question 11

the basis of Parkinson’s is:

Answer 11

loss of dopaminergic neurons in the substantia nigra. mutations in synuclein gene - can’t keep up with degrading misfolded proteins.
Find: Lewy body proteins accumulate containing a-synuclein and ubiquitin

Question 12

treatments for Parkinson’s include:

Answer 12

1. L-Dopa/carbidopa (dopamine precursor)
2. partial pallidotomy - remove part of globus pallidus internus
3. deep brain stimulation to inactive neurons in sub thalamic nucleus
4. (experimental) virus-mediated gene therapy: construct virus carrying GAD (transcription factor) to increase inhibition to subthalamic nucleus
5. growth factors - neurotrophins -