Annels, such as mammalian isoforms (Table 1). Using sequence homology with Shaker, introduction of cysteines in to the extracellular loop of mammalian voltagegated ion channels has been used to endow quite a few channels with photosensitivity with related properties to SPARK (Figure 1B). This technique was applied to 3 members of distinctive subfamilies of voltagegated channels such as Kv1.3, Kv3.1, and the Mcurrent channel Kv7.two (Table 1). Photocontrol was also applied to one of many Ca2 activated K channels that generates the longlasting action prospective afterhyperpolarizationTable 1 | PTLmediated photoswitchable ion channels. Channel Family members Cysteine cis or trans block Drosophila Shaker 646 L366A T449V “SPARK” “DSPARK” V443Q Kv E422C trans Kv E422C trans Atype current Voltagegated V1/2 = 36 mV Weak inactivation Properties(SK2; Fortin et al., 2011). Considering that these channels exhibit distinctive biophysical properties and subcellular targeting, they might enable precise aspects of neuronal function to become controlled by light. Fortin et al. (2011) proposed to use KV 7.2 to control the resting membrane possible, because it features a low activation threshold and Kv3.1 to manage accommodation simply because these channels possess a highthreshold of activation and activate and deactivate rapidly (Gan and Kaczmarek, 1998). Most notably, photoswitchable SK2 channels were used to manage the size of EPSPs in CA1 hippocampal neurons exactly where they may be natively involved in dendritic repolarization following glutamate receptormediated depolarization (Fortin et al., 2011).OPTICAL Control OF K2P POTASSIUM CHANNELS: TREKlight K2P channels are just about the most diverse and critical subfamilies of potassium channels. They serve as a hub for the generation and regulation of a adverse resting membrane prospective and therefore,Potential neuronal applicationsReferencePhotocontrol of VmBanghart et al. (2004)Nonselective cation channel Voltagegated V1/2 = 36 mVPhotocontrol of VmChambers et al. (2006)Kv1.3H401YKvP374CtransVoltagegated V1/2 = 30 mVPhotocontrol of AccomodationFortin et al. (2011)Kv3.KvE380CtransWeak inactivation V1/2 = 40 mVPhotocontrol of VmFortin et al. (2011)Kv7 .KvE257CtransMtype present V1/2 = 30 mV Ca2 activated Leak present pHsensitive In depth regulationPhotocontrol of Vm Photocontrol of Mcurrent Photocontrol of afterhyperpolarization Photocontrol of VmFortin et al.1627973-06-1 uses (2011)SK2 TREK1/K2P two.Formula of (R)-3-Methylpiperidine hydrochloride 1 “TREKlight”SK K2PQ339C S121Ctrans cisFortin et al.PMID:33597223 (2011) Sandoz et al. (2012)TREK1/K2P 2.1 “SRARKlike”K2PK231CtransLeak present pHsensitive In depth regulationPhotocontrol of VmSandoz et al. (2012)TREKCK2PS121CcisLeak existing pHsensitive Comprehensive regulationPhotocontrol of native TREK1 ConductionSandoz et al. (2012)”TREK1PCS”TASK3/K2P 9.K2PR73C or A74CtransLeak current pHsensitive Substantial regulationPhotocontrol of VmSandoz et al. (2012)Frontiers in Molecular Neurosciencewww.frontiersin.orgApril 2013 | Volume six | Short article six |Sandoz and LevitzOptogenetics of potassium channelscellular excitability. As well as background roles as leak channels, K2P channels also play a central role within the dynamic response of cells to extracellular and intracellular signals as diverse as GPCR signaling, pH, and membrane stretch. TWIK1related K channel 1 (TREK1), a specifically wellstudied K2P channel, has been located to be involved in quite a few physiological processes such as neuroprotection against ischemia (Heurteaux et al., 2004), discomfort perception (Noel et al., 2011), and depression (Heurteaux et a.