All-optical mapping of Ca2+ transport and homeostasis in dendrites
Year: 2024
Type: article
Abstract: Calcium mediates many important signals in dendrites. However, the basic transport properties of calcium in dendrites have been difficult to measure: how far and how fast does a local influx of calcium propagate? We developed an all-optical system for simultaneous targeted Ca 2+ import and concentration mapping. We co-expressed a blue light-activated calcium selective channelrhodopsin, CapChR2, with a far-red calcium sensor, FR-GECO1c, in cultured rat hippocampal neurons, and used patterned optogenetic stimulation to introduce calcium into cells with user-defined patterns of space and time. We determined a mean steady-state length constant for Ca 2+ transport ϕ ∼ 5.8 μm, a half-life for return to baseline t 1/2 ∼ 1.7 s, and an effective diffusion coefficient D ∼ 20 μm 2 /s, though there were substantial differences in Ca 2+ dynamics between proximal and distal dendrites. At high Ca 2+ concentration, distal dendrites showed nonlinear activation of Ca 2+ efflux, which we pharmacologically ascribed to the NCX1 antiporter. Genetically encoded tools for all-optical study of Ca 2+ transport and handling provide a powerful capability for studying this important messenger.
Source: Cell Calcium
Authors: Rebecca Frank Hayward, Adam E. Cohen
Institution: Harvard University
Language: English
Subfield: Biophysics
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $3,660
OpenAlex ID: W4405046461