Term
|
Definition
dynamic ends of developing
axons that feel around for guiding factors to
tell it where to go |
|
|
Term
|
Definition
Cell-adhesion molecules
or CAMs act like velcro to pull the growth
cone along |
|
|
Term
|
Definition
(such as tropic molecules like Slit)
are chemical signals that either attract or
repel the growth cone |
|
|
Term
|
Definition
| "Sheet-like" projection of axon |
|
|
Term
|
Definition
| Filopodia (also microspikes) are slender cytoplasmic projections that extend beyond the leading edge of lamellipodia in migrating cells and act as feelers. |
|
|
Term
|
Definition
| the extracellular part of animal tissue that usually provides structural support to the animal cells in addition to performing various other important functions. |
|
|
Term
| Cell Adhesion Molecules (CAMs) |
|
Definition
| proteins located on the cell surface[1] involved in binding with other cells or with the extracellular matrix (ECM) in the process called cell adhesion. Essentially, cell adhesion molecules help cells stick to each other and to their surroundings. |
|
|
Term
|
Definition
Guide axons to the correct location
• Netrins = can be attractive or repellant
• Slit (signal)/Robo (receptor) = repellant
• Semaphorins = repellant
• Ephrin = “forward” and “reverse” signaling,
often repellant but can attract (not really longrange signals) |
|
|
Term
|
Definition
specific neurons are
guided to specific targets by specific recognition
molecules |
|
|
Term
|
Definition
Bind GTP
• Control actin assembly/disassembly
• GTP-bound = active
• GDP-bound = inactive
• Guanine nucleotide Exchange Factors (GEFs) activate
Rho GTPases
• GTPase Activating Proteins (GAPs) turn off Rho GTPases |
|
|
Term
|
Definition
|
|
Term
| GTPase Activating Protein |
|
Definition
|
|
Term
|
Definition
| Attractive or Repellent Tropic Signals |
|
|
Term
|
Definition
| • Slit (signal)/Robo (receptor) = repellant |
|
|
Term
|
Definition
“forward” and “reverse” signaling,
often repellant but can attract (not really longrange signals) |
|
|
Term
| What are filopodia full of? |
|
Definition
|
|
Term
| Do attractive signals cause actin to polymerize or depolymerize? What about repulsive signals? |
|
Definition
active=polymerize
inactive=depolymerize |
|
|
Term
| Give 3 examples of tropic signals. Which are attractants and which are repellants? |
|
Definition
netrins =attractive or repellant
slit and robo=repellant |
|
|
Term
Tell about the experiment outlined in Lecture 7 in which a frog’s eyeball was removed, turned
around so that the anterior portion was now posterior and vice versa, and put back in. What
were the behavioral consequences? What does this tell us about neurons and their synaptic
targets? |
|
Definition
The frog sees its stimuli to the right but it will continually strike downward. Remember, frog CNS can regenerate, unlike
mammals’! |
|
|
Term
In the chick visual system, temporal retinal neurons project to anterior tectum, but nasal retinal
projections project through the anterior tectum to the posterior tectum. How do gradients in
receptor expression in retinal neurons and ephrin expression in the tectum make this possible? |
|
Definition
• Ephrins act as repellants,
– Temporal axons with high levels of receptors can only
make it into anterior tectum with low levels of signal
– Nasal axons with low levels of receptor can make it
into areas even with high levels of signal |
|
|
Term
Explain how Rho GTPases are turned on and off. Is GTP-associated Rho active or inactive? What
about GDP-associated Rho? What turns there proteins on? Off? |
|
Definition
| Rho GTPases are turned on when they bind to Guanine nucleotide Exchange Factors (GEFs). They are turned off by GTPase Activating Proteins (GAPs). |
|
|
Term
. Explain Slit/Robo interactions. Are they attractants or repellants? Which is expressed by the
growth cone (receptor) and which is the signal (ligand)? |
|
Definition
| Slit is the ligand and robo is the receptor. |
|
|
Term
In the Drosophila embryo, where is there the most Slit? Where is the most Robo? After
crossing the midline, do neurons express more or less Robo than they did before crossing?
Why? |
|
Definition
| Slit is strongly expressed by midline glia; a little on the sides |
|
|
Term
Explain Ephrin/Eph interactions. Which is expressed by the growth cone (receptor) and which is
the signal (ligand)? |
|
Definition
Ephrin is the ligand
eph is the receptor |
|
|
Term
|
Definition
| Muscles in the hand contract (neurological) |
|
|
Term
|
Definition
| MRI that images movement of molecules (water mostly) from the mid 80s |
|
|
Term
|
Definition
| a critical period is a phase in the life span during which an organism has heightened sensitivity to exogenous stimuli that are compulsory for the development of a particular skill. |
|
|
Term
|
Definition
| Ocular dominance columns are stripes of neurons in the visual cortex of certain mammals (including humans[1]) that respond preferentially to input from one eye or the other |
|
|
Term
|
Definition
| Fire together wire together |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
Made by motor neurons
• Transported down axons
• Released into the synaptic cleft
• Believed to organize postsynaptic structures in
the muscle (Jones et al., 1997) |
|
|
Term
|
Definition
differential adhesion
among connections |
|
|
Term
|
Definition
trophic factors either
preferentially supplied
to or used by “winner”
axons
• Synaptotoxi |
|
|
Term
|
Definition
possible negative
signals inducing
withdrawal |
|
|
Term
|
Definition
| Nurishment/Regulates growth |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
