32 Questions
What happens to the number of motoneurons if a limb bud is removed from a chick embryo?
The number of motoneurons decreases.
What effect does increasing the size of a limb target by transplanting an extra limb bud have on motoneuron death?
Reduces motoneuron death.
What is the main role of trophic factors in relation to neurons?
To support neuron survival.
What is the function of Nerve Growth Factor (NGF) according to the text?
Support neuron survival and axon outgrowth.
What happens if NGF function is disrupted in vivo according to the text?
Dramatic loss of neurons in the ganglion.
Which statement best describes the role of neurotrophins?
Support neurons in both CNS and PNS.
What effect does adding curare (a drug blocking muscle contractions) have on motoneurons?
Supports motoneuron survival.
Which molecule is responsible for the trophic activity of Nerve Growth Factor (NGF)?
'Trophic' molecule
Which neurotrophin binds all the TRKs?
NT3
What is the function of p75 in response to neurotrophin binding?
Induces apoptosis
How are all trks activated?
By heterodimerization
Which adaptor protein binds to phosphorylated Shc after trkA activation?
Grb2
What is the role of Akt in promoting cell survival?
Inhibiting apoptosis by activating Bcl2
Which protein inhibits apoptosis by promoting the exchange of GDP for GTP bound to Ras?
Sos
What is the main outcome of injecting DNA for activated MEK into PC12 cells?
Protein synthesis + neurite growth
What happens when neurotrophins regulate the ras/raf/mek/erk kinase cascade?
Regulation of neurite outgrowth
What is the primary function of downstream effector proteins in neurotrophin signaling pathways?
Regulation of cell survival and growth processes
What characterizes the binding affinity between neurotrophins and p75 receptor?
All neurotrophins bind with similar affinity
What are the 4 classic morphological features characteristic of apoptosis?
Cell and nuclear shrinkage, chromatin condensation, cellular fragmentation, phagocytosis of cell remains
What is the purpose of apoptosis during development according to the text?
To sculpt the final tissue structure by removing unnecessary cells
Which process involves an active biochemical program leading to cell death often referred to as 'cell suicide'?
Apoptosis
How was apoptosis first imaged according to the text?
By electron microscopy (EM)
Which term describes cell death resulting from traumatic injury involving rapid cell lysis?
Necrosis
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
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
How does apoptosis contribute to sculpting the final tissue structure during development?
By removing unnecessary cells after overproduction.
In apoptosis, what happens to the cell during the process?
The cell takes itself apart and packages itself into vesicles called apoptotic bodies.
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.
Which family member inhibits ced-4 to prevent caspase cleavage?
ced-9
What is considered the 'point of no return' in apoptotic cell death?
Caspase activation
Where does neurotrophin signaling occur due to retrograde transport of a vesicle carrying the trk receptor?
Cell body
Which hormone readily crosses the blood-brain barrier and regulates gene expression by translocating to the nucleus?
Testosterone
Explore the functions of Neurotrophins NT4/5 in neuronal survival, nerve growth, nerve sprouting, anabolic actions, differentiation, modulation and transmission, as well as electrical properties.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
