SenseLab
Cellular Ionic Currents

Comparitive Search: clicking on a current shows all cells which contain that current.

I Sodium
I Na,t"Transient"; rapidly inactivatingAction potentials
I Na,pPersistent (plateau); non-inactivating; TTX-resistantEnhances depolarizations; contributes to steady-state firing
I Potassium
I A, slowSlowly inactivating "delay" current I K(D)Similar to A-type current but inactivates slowly (seconds). Participates in spike repolarization.
I A"Transient"; inactivatingDelayed onset of firing; interspike interval; action potential repolarization
I K,leakContributes to neuronal resting "leak"conductanceHelps determine resting membrane potential
I KActivated by strong depolarization; delayed rectifierRepolarization of action potential
I MActivated by depolarization above -65 mV; slow, weak and non-inactivating; blocked by ligands like acetylcholine acting through muscarinic (M) receptorsContributes to slow spike frequency adaptation
I Calcium
I L high threshold"Long-lasting"; slowly inactivating; threshold around -20 mVUnderlies Ca2+ spikes that are prominent in dendrites; involved in synaptic transmission
I N"Neither"; rapidly inactivating; threshold around -20 mVUnderlies Ca2+ spikes that are prominent in dendrites; involved in synaptic transmission
I T low threshold"Transient"; rapidly inactivating, threshold negative to -65mVUnderlies rhythmic burst firing; some dendritic action potentials
I p,qIncludes both p-type and q-type currents
I Chloride
I Cl,CaCalcium activated chloride currentCan enhance or decrease response depending on the Cl- equilibrium potential
I Mixed
I K,CaIncludes BK, IK, SK, and I AHP currents; K current activated by increases in [Ca2+]i; voltage dependence variesAction potential repolarization and interspike interval
I CNGCyclic-Nucleotide Gated nonspecific cation channelDark current in photoreceptors, activated by cGMP; light response in ON retinal bipolar cells; receptor current in olfactory sensory neurons, activated by cAMP, modulated by cGMP; found widely in CNS neurons
I CANCalcium Activated Nonspecific cation channel
I hInward rectifier; "Queer"; activated by hyperpolarization/mixed cation currentPrevents strong hyperpolarization; increases membrane resistance during membrane depolarization