A molecular light switch turns off neural activity

Access through your institution Buy or subscribe Voltage-gated potassium channels can be blocked by quaternary ammonium (QA) ions that bind to amino acids in the pore-lining region. Kramer

and colleagues synthesized a tether attached to a QA group, which can covalently bind to a potassium channel that the authors modified to make the QA blocker the primary determinant of its

gating. A section of the tether is photoisomerizable, meaning that its conformation can be changed by light. Shining light of a long wavelength (500 nm) shifts the tether into a long form,

whereas light of a shorter wavelength (380 nm) shifts it to a shorter form. In the long form, the attached QA group can access and block the potassium channel pore, turning the channel off,

but in the short form, the QA group does not reach the channel, allowing potassium ions to flow out of the cell. Because potassium efflux causes neurons to become hyperpolarized, the

short-wavelength light can silence activity in hippocampal neurons exogenously expressing the SPARK channels. This new technique should find wide applicability in studies of circuit function

and in other manipulations of neuronal activity. In addition, it should spark the development of more experimental, and perhaps therapeutic, tools. This is a preview of subscription

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ACCESS OPTIONS: * Log in * Learn about institutional subscriptions * Read our FAQs * Contact customer support Authors * Cara Allen View author publications You can also search for this

author inPubMed Google Scholar RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Allen, C. A molecular light switch turns off neural activity. _Nat

Neurosci_ 7, 1291 (2004). https://doi.org/10.1038/nn1204-1291 Download citation * Issue Date: 01 December 2004 * DOI: https://doi.org/10.1038/nn1204-1291 SHARE THIS ARTICLE Anyone you share

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