Neurobio exam 3

Which describes an increased amplitude postsynaptic response that lasts for milliseconds?

Facilitation

Which describes an increased amplitude postsynaptic response that lasts for hours?

Long-term potentiation

Which describes an increased amplitude postsynaptic response that lasts for minutes?

Post-tetanic potentiation

Which describes a decreased amplitude postsynaptic response that lasts for hours?

Long-term depression

Which is thought to be the result of the activation of silent synapses? 

Postsynaptic expression of LTP

Which is generally found in both LTD and LTP? 

A dependence on postsynaptic concentration of calcium   

Which is needed for NMDA receptor channels to allow calcium to enter? 

Glutamate needs to be released and the postsynaptic membrane needs to be depolarized 

NMDA channels are unusual in that at resting membrane potential they are blocked by

magnesium ion blocking the channel from the extracellular side 

Calcium calmodulin-dependent protein kinase II (CaMKII) is necessary for LTP because

once activated by calcium, it can auto-phosphorylate and activate itself after calcium concentration lowers     

Which is needed for NMDA receptor channels to allow calcium to enter?

Glutamate needs to be released and the postsynaptic membrane needs to be depolarized 

How fast does gene expression of immediate early genes (IEGs) occur?

Minutes 

Some IEGs encode effector proteins, like _______, that directly regulate synaptic function. 

BDNF

Neuroepigenetics is  

A persistent modification of the organization of the chromatin without altering the genome sequence in a neuron 

BDNF promoter IV is bound to several transcriptional factors that recruit repressor complexes. When calcium influx occurs the transcription factors are turned into 

an active transcriptional state 

Since mRNAs appear to not rest but continuously patrol the dendrites, how are they functionally regulated

They travel in a repressed state but synaptic activity releases mRNAs from their translationally repressed state 

Which of the following is involved with depolarization –induced suppression of inhibition (DSI) and long term depression (iLTD)? 

GABAergic synapses 

Which best describes the relationship between microRNAs (miRNA) and synaptic plasticity? 

miRNA directs translational repression or mRNA degradations depending on the degree of complementarity between the miRNA and the sequences on target mRNAs

Reprogramming mature, differentiated somatic cells with Oct4, Sox2, Klf4, c-Myc can produce 

induced pluripotent stem cells (iPSCs)

Cell differentiation can be regulated by  

transcription factors 

juxtacrine signaling 

paracrine signaling    

The decay of facilitation at a neuromuscular junction over time likely represents a(n)

Return of intracellular calcium to its resting level 

Which of the following explains the mechanism for the response seen in a high-calcium bath for the frog neuromuscular junction preparation? 

Large quintal release in high calcium bath 

Which of the following is thought to be the result of the activation of silent synapses? 

Post synaptic expression of LTP 

Which of the following is more involved in LTD than LTP? 

Protein phosphatases 

The dendritic depolarization to allow calcium passage through NMDA channels is dependent on a(n) 

action potentials generated in the dendrites

Which of the following appear involved in iLTD? 

Cannabinoid receptors 

Which of the following was found following motor training in forelimb-reaching motor task?

Only changes in the motor cortex ipsilateral to the trained limb 

Which of the following assists the nucleus to distinguish between the activation of synaptic or extrasynaptic NMDA receptors?

The phosphorylation state of Jacob 

Where is Arc located two hours over after transcription? 

Distil dendrites 

How does dendritic mRNAs for CaMKII get to the correct location? 

There is a variable signaling sequence on the dendritic mRNAs that act as zip codes.

Which is involved with depolarization-induced suppression of inhibition (DSI) and long-term depression (iLTD)?

GABAergic synapses 

Which is a major target for translational control of synaptic plasticity? 

The assembly of a translationally competent ribosome on the mRNA 

Which of the following best describes microRNAs (miRNA)? 

22-23 nucleotide noncoding piece of RNA 

Arc is ______ by stimuli that produce persistent synaptic potentiation yet is also contributes to weakening of synapses. 

upregulated 

 How is neuronal activity linked to expression of a reporter gene? 

Activity stimulates Fos-promoter which in transgenic lines can drive iTA, a transcription factor that activates transcription of LacZ which encodes B-galactosidase.

Which process involves the production of a marker that allows stimulated spines to capture molecules that assist in plastic changes for memory encoding?

Synaptic tagging and capture 

Induced pluripotent stem cells (iPSCs) can be created by reprogramming differentiated somatic cells with the following factors. 

Oct4, Sox2, Klf4, c-Myc 

During the process of lateral inhibition, the neuroblast is determined by 

Elevated levels of Delta

Which statement about Hox genes is incorrect?

A specific Hox gene is only expressed in a specific segment along the anteroposterior axis. 

In the adult mammalian brain, neurogenesis occurs in which layer? 

Subventricular zone 

Which cell type is not derived from neural crest cells? 

Motor neuron 

Robo is a receptor for the axon guidance molecule 

slit

Which statement about nerve growth factor (NGF) is incorrect? 

NGF binds TrkB receptor.

Which protein has been implicated in CNS synapse formation? 

Neurexin 

The human brain has an increased size and complexity as a result of the 

presence of outer radial glia cells. 

Hox genes are 

transcription factors 

This embryonic structure induces the floor plate 

Notochord   

This morphogen is involved in ventral patterning of the nervous system 

Shh

The following guidance cue mediates long-range attraction 

Netrin-1 

Which protein causes acetylcholine receptor clustering?

Agrin 

What is the primary role associated with oligodendrocytes? 

They form the myelin sheath around the axons within the CNS 

you are provided with a slide of cells taken from an adult CNS and must label which are neurons and which are glial cells. What is one way to tell them apart?

Glial cells do not have axons

Which statement about microglia is true?

They develop from the mesoderm and are found in the central nervous system

Which of the following is true about NG2 cells in the developing nervous system? 

They are precursor to both oligodendrocytes and astrocytes 

In the next unit we will be discussing the overlap between Neurobiology and Cancer Biology. Glial cells have been found to be the most common source of tumors in the brain. Why might this be?  

Certain glial cells can divide 

Which of the following is a key function of astrocytes?

They contribute to the blood-brain barrier.

Which type of glial cell myelinates axons in the central nervous system? 

Oligodendrocytes 

Glial processes are typically _______ neural processes. 

thinner than 

Glial cell resting potentials are generally _______ than neuron resting potentials

more negative

Certain glial cells can respond to injury in the CNS. What is one characteristic found in these cells (but not neurons) that allows this to occur? 

The glial cells can replicate. 

Spatial buffering is the process by which 

glial cells take up potassium released by nearby neurons. 

What is one unique neurotransmitter that is released by glial cells, but not neurons? 

serine 

Molecules that enter the brain through the bloodstream must pass 

Directly through endothelial cells