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Elleman, A. V.

Publications and source records attributed to Elleman, A. V..

2 recordsLinked to original sources

Behavioral control through the direct, focal silencing of neuronal activity

Voltage-gated sodium channel (NaV) activity underlies electrical signaling, synaptic release, circuit function, and, ultimately, behavior. Molecular tools that enable precise control of NaV subpopulations make possible temporal regulation of neuronal activity and cellular communication. To rapidly modulate NaV currents, we have rendered a potent NaV inhibitor, saxitoxin, transiently inert through chemical protection with a novel nitrobenzyl-derived photocleavable group. Light-induced uncaging of the photocaged toxin, STX-bpc, effects rapid inhibitor release and focal NaV block. We demonstrate the efficacy of this reagent for manipulating action potentials in mammalian neurons and brain slice and for altering locomotor behavior in larval zebrafish. Photo-uncaging of STX-bpc is a non-invasive, effective method for reversible, spatiotemporally precise tuning of NaV currents, application of which requires no genetic manipulation of the biological sample.

neuroscience↗

Precise spatiotemporal control of voltage-gated sodium channels by photocaged saxitoxin

Here we report the pharmacologic blockade of voltage-gated sodium ion channels (NaV) by a synthetic saxitoxin derivative affixed to a photocleavable protecting group. We demonstrate that a functionalized saxitoxin (STX-eac) enables exquisite spatiotemporal control of NaV blockade to interrupt action potentials (APs) in dissociated neurons and nerve fiber bundles. The photo-uncaged inhibitor (STX-ea) is a nanomolar potent, reversible binder of NaVs. We use STX-eac to reveal differential susceptibility of myelinated and unmyelinated axons in the corpus callosum to NaV-dependent alterations in AP propagation, with unmyelinated axons preferentially showing reduced AP fidelity under conditions of partial NaV blockade. These results validate STX-eac as a high precision tool for robust photocontrol of neuronal excitability and AP generation.

neuroscience↗