Neuro16 - 14 Flashcards
What happens to resting potential during development?
Falls by introduction of new channels and new pumps
When do action potentials start arising?
Early after last mitosis
What are the two principal routes of AP development?
Long Ca-dependent then short Na-dependent; OR short na-dependent
What are rohon-beard cells?
Mechanosensory cells of lower vertebrate dorsal spinal cord
What is a delayed rectifier?
Channel that only allows current through one way, but only opens some time after its voltage threshold has been reached
What does the inclusion of K channel delayed rectifiers do?
Shortens AP - delays K expulsion from cells after action potential
How does excitablity develop?
Non-excitable > single AP > low frequency > high frequency (complex)
What do Ca channels appear as?
Low voltage activated T-currents
What do mature to high voltage activated channels have?
N- and L-currents
What do waves of calcium channel activation cause?
Process growth, differentiation, greater GAD and GABA at high frequency, more growth at low
What does receptor development involve?
Changes in population, subunits and/or localisation
Outline GABAa development
Depolarise > immature have high Cl, causing Na/Ca influx > increased KCC2 expression, decreased NKCC1 expression > switches effect to hyperpolarisation
What is KCC2?
K/Cl co-transporter (out)
What is NKCC2?
Na/K/Cl co-transporter (in)
