Neuronal Ionic Currents

Comparitive Search: clicking on a current shows all cells and all compartments within those cells which contain that current.

I Sodium
I Na,t "Transient"; rapidly inactivating Action potentials
I Na,p Persistent (plateau); non-inactivating; TTX-resistant Enhances depolarizations; contributes to steady-state firing
I Potassium
I A, slow Slowly inactivating "delay" current I K(D) Similar to A-type current but inactivates slowly (seconds). Participates in spike repolarization.
I A "Transient"; inactivating Delayed onset of firing; interspike interval; action potential repolarization
I K,leak Contributes to neuronal resting "leak"conductance Helps determine resting membrane potential
I K Activated by strong depolarization; delayed rectifier Repolarization of action potential
I M Activated by depolarization above -65 mV; slow, weak and non-inactivating; blocked by ligands like acetylcholine acting through muscarinic (M) receptors Contributes to slow spike frequency adaptation
I Calcium
I L high threshold "Long-lasting"; slowly inactivating; threshold around -20 mV Underlies Ca2+ spikes that are prominent in dendrites; involved in synaptic transmission
I N "Neither"; rapidly inactivating; threshold around -20 mV Underlies Ca2+ spikes that are prominent in dendrites; involved in synaptic transmission
I T low threshold "Transient"; rapidly inactivating, threshold negative to -65mV Underlies rhythmic burst firing; some dendritic action potentials
I p,q Includes both p-type and q-type currents
I Chloride
I Cl,Ca Calcium activated chloride current Can enhance or decrease response depending on the Cl- equilibrium potential
I Mixed
I K,Ca Includes BK, IK, SK, and I AHP currents; K current activated by increases in [Ca2+]i; voltage dependence varies Action potential repolarization and interspike interval
I CNG Cyclic-Nucleotide Gated nonspecific cation channel Dark 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 CAN Calcium Activated Nonspecific cation channel
I h Inward rectifier; "Queer"; activated by hyperpolarization/mixed cation current Prevents strong hyperpolarization; increases membrane resistance during membrane depolarization