Functions of Neurotrophins NT4/5

Play an AI-generated podcast conversation about this lesson

What happens to the number of motoneurons if a limb bud is removed from a chick embryo?

The number of motoneurons varies randomly.

The number of motoneurons remains the same.

The number of motoneurons increases.

The number of motoneurons decreases. (correct)

What effect does increasing the size of a limb target by transplanting an extra limb bud have on motoneuron death?

Causes random changes in motoneuron death.

Has no impact on motoneuron death.

Reduces motoneuron death. (correct)

Increases motoneuron death.

What is the main role of trophic factors in relation to neurons?

To induce neuronal migration.

To support neuron survival. (correct)

To stimulate axon growth.

To provoke apoptosis.

What is the function of Nerve Growth Factor (NGF) according to the text?

Support neuron survival and axon outgrowth. Signup and view all the answers

What happens if NGF function is disrupted in vivo according to the text?

Dramatic loss of neurons in the ganglion. Signup and view all the answers

Which statement best describes the role of neurotrophins?

Support neurons in both CNS and PNS. Signup and view all the answers

What effect does adding curare (a drug blocking muscle contractions) have on motoneurons?

Supports motoneuron survival. Signup and view all the answers

Which molecule is responsible for the trophic activity of Nerve Growth Factor (NGF)?

'Trophic' molecule Signup and view all the answers

Which neurotrophin binds all the TRKs?

NT3 Signup and view all the answers

What is the function of p75 in response to neurotrophin binding?

Induces apoptosis Signup and view all the answers

How are all trks activated?

By heterodimerization Signup and view all the answers

Which adaptor protein binds to phosphorylated Shc after trkA activation?

Grb2 Signup and view all the answers

What is the role of Akt in promoting cell survival?

Inhibiting apoptosis by activating Bcl2 Signup and view all the answers

Which protein inhibits apoptosis by promoting the exchange of GDP for GTP bound to Ras?

Sos Signup and view all the answers

What is the main outcome of injecting DNA for activated MEK into PC12 cells?

Protein synthesis + neurite growth Signup and view all the answers

What happens when neurotrophins regulate the ras/raf/mek/erk kinase cascade?

Regulation of neurite outgrowth Signup and view all the answers

What is the primary function of downstream effector proteins in neurotrophin signaling pathways?

Regulation of cell survival and growth processes Signup and view all the answers

What characterizes the binding affinity between neurotrophins and p75 receptor?

All neurotrophins bind with similar affinity Signup and view all the answers

What are the 4 classic morphological features characteristic of apoptosis?

Cell and nuclear shrinkage, chromatin condensation, cellular fragmentation, phagocytosis of cell remains Signup and view all the answers

What is the purpose of apoptosis during development according to the text?

To sculpt the final tissue structure by removing unnecessary cells Signup and view all the answers

Which process involves an active biochemical program leading to cell death often referred to as 'cell suicide'?

Apoptosis Signup and view all the answers

How was apoptosis first imaged according to the text?

By electron microscopy (EM) Signup and view all the answers

Which term describes cell death resulting from traumatic injury involving rapid cell lysis?

Necrosis Signup and view all the answers

What was the significance of the first experiments performed to prove apoptosis as an active biochemical process?

They indicated that protein synthesis is needed for apoptosis Signup and view all the answers

What process involves balancing the number of neurons with the amount of target that needs to be innervated in the nervous system?

Programed Cell Death (PCD): Apoptosis Signup and view all the answers

How does apoptosis contribute to sculpting the final tissue structure during development?

By removing unnecessary cells after overproduction. Signup and view all the answers

In apoptosis, what happens to the cell during the process?

The cell takes itself apart and packages itself into vesicles called apoptotic bodies. Signup and view all the answers

Why did the first experiments using mRNA/protein synthesis inhibitors help prove apoptosis as an active biochemical process?

They blocked apoptosis which indicated a need for protein synthesis. Signup and view all the answers

Which family member inhibits ced-4 to prevent caspase cleavage?

ced-9 Signup and view all the answers

What is considered the 'point of no return' in apoptotic cell death?

Caspase activation Signup and view all the answers

Where does neurotrophin signaling occur due to retrograde transport of a vesicle carrying the trk receptor?

Cell body Signup and view all the answers

Which hormone readily crosses the blood-brain barrier and regulates gene expression by translocating to the nucleus?

Testosterone Signup and view all the answers