Channels and transporters lec 6 Flashcards
Voltage gated Na channels
inward current flow greater the depolarization the higher the prob or channel opening need many channels to create AP inactivate current reverses at Ena TTX block
Voltage gated K channels
Outward current flow
delayed opening
many do not inactivate
TEA and Cs+ block
Fast AHP Bk
Shortens AP
Effects how soon you can get another AP
Activation by Ca
Medium AHP Ik and Sk
contributes to early spike freq adaptation
slowly activated by Ca entry
Controls late spike freq adaptation
Non-inactivating
Slow AHP
Limits firing freq
Ka
inactivates rapidly
Kdr
inactivates slowly or not at all
Kbk
Ca activated and depolarization required
Kv4.1 channels
Play positive role in tumorigenic human mammary cells
inactivate rapidly to depolarization
Kv2.1 channels
Show little inactivation and are related to channels involved in repolarization
Inward rectifier channels
Allow more current flow during hyperpolarization than during depolarization
Ca activated K channel
Opens in response to increased Intracellular Ca
Membrane potential is shifted right (more +) when Ca concentration is decreased
Voltage gated Ca channelpathies
Congenital stationary night blindness
familial hemiplegic migraine
episodic ataxia type 2
Na channel defect
Generalized epilepsy with febrile seizures
K channel mutation
benign familial neonatal convulsion
