Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
|
what allows growth cone mobility |
dynamic protein action allows axonal growth cone mobility; the growth of actin in a direction |
|
|
the signaling involved in axon guidance |
diffusible signaling= netrin/slit and semaphorins; non diffusible signaling= ECMs, CAMS, cadherins, and ephrins |
|
|
axon guidance: diffusible signals: what 2 factors |
tropic factors= guide growing axons to a source; trophic factors= support survival and growth; chemoattractants= best characterized is the netrin family; chemorepellant= no go's, semiphorins, etc |
|
|
chemoaffinity hypothesis |
growing axons respond, either positively or negatively, to chemical gradients of molecules |
|
|
selective synapse formation |
local determinants allow selectivity of synapse formation; synapse will form or growth cone will retract to reach another target or there is a failure to forma synapse followed by death |
|
|
molecular mechanisms of synapse formation |
protocadherins and cadherins initiate the formation of synapses |
|
|
neurotrophins can activate what different responses |
cell survival/death; synapse stabilization/elimination; neuronal process growth/retraction |
|
|
the neuromuscular junction: classic example of neuronal connection and synapse stabilization |
at first there are many neurons that innervate the same muscle fiber; this gets pruned down to one per muscle fiber
|
|
|
neurotophin specificity |
ligands= nerve growth factor (NGF), brain derived neurtrophic factor (BNDF), neurotrophin 3 (NT-3), neurotrophin 4/5 (NT-4/5; receptors= tyrosine kinase (Trk), p75 aka nerve growth factor receptor (NGFR) |
|
|
definition of a critical period in neural development |
temporal window of time in which experience can modify the developing brain; the mechanisms that mediate critical periods remain largely unknown |
|
|
the 3 important critical periods in neural development |
language acquisition; binocular vision development; sexual differentiation of the brain |
|
|
critical periods for visual system development: changes in ocular dominance patterning |
visual deprivation changes ocular dominance patterning |
|
|
ocular asynchrony prevents what |
binocular vision |
|
|
visual deficits: ambylopia |
loss of acuity, diminished stereopsis or problems with fusion; strabismus= eye misalignment (lazy eye) |
|
|
visual deficits: cataracts |
opaque lens; onchocerciasis aka river blindness due to onchocerca valvus; trachoma due to chlamydia trachomatis |
