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Defiance International

Study type: In vitro · Status: Evidence verified by machine against declared source

A Gq-Ca2+ axis controls circuit-level encoding of circadian time in the suprachiasmatic nucleus.

Neuron · 2013

Study scale: CCD real-time imaging identified significant numbers of transduced cells (mean ± SEM = 128 ± 26 cells/SCN n = 5; Figures 1A and 1B; see Movie S1 available online).

Abstract only: Open source record

Product or molecular entity relationships

  • VIP: Exact entity relationship. Legacy citation custody associates this source with the catalog record; no product-relevance conclusion is implied.

Public plain-language summary

The published text is limited to the declared source and preserves reported uncertainty. It does not establish efficacy, safety, suitability, or evidence strength.

Research question

Having characterized this program, and shown its dependence upon neuropeptidergic G-coupled signaling, we then sought to examine causal relationships within it.

Study design

Moreover, because organotypic SCN slices are a faithful representation in vitro of circadian time-keeping in vivo, they constitute a powerful model to explore the interplay between cell-intrinsic and circuit-based properties in the specification of a fundamental, adaptive behavior (Welsh et al., 2010).

Participants or experimental system

Unraveling the circadian timekeeping properties of the suprachiasmatic nucleus has focused upon cell-autonomous transcriptional feedback loops.

Study scale

CCD real-time imaging identified significant numbers of transduced cells (mean ± SEM = 128 ± 26 cells/SCN n = 5; Figures 1A and 1B; see Movie S1 available online).

Intervention or exposure

In the context of the SCN neuron, activation of CREs therefore provides a valuable report of the integrated afferent information received from the intercellular SCN network for transmission to the intracellular TTFL clockwork (Travnickova-Bendova et al., 2002).

Comparator

In contrast, contributions from G-coupled pathways and cytosolic rhythms to the intercellular control of SCN pacemaking are poorly understood.

Outcomes examined

Brancaccio et al. now reveal that a Gq-[Ca2+]i axis encodes circadian time at the level of the suprachiasmatic neuronal circuitry.

Key findings

We phase-mapped them to the TTFL, in time and SCN space, and demonstrated their dependence upon G-coupled vasoactive intestinal peptide (VIP) signaling.

Limitations and uncertainty

Importantly, this occurred in otherwise genetically intact SCN circuits, not subject to the developmental confounds associated with germ-line mutations or embryonic chimerism (Ko et al., 2010; Low-Zeddies and Takahashi, 2001).

Product relevance and evidence boundary

This record is a published study, held here with its citation and review status. It is not a statement that any catalog item is effective, safe, or suitable for any use, and nothing in it is a dose or a protocol.

Evidence verified by machine against declared source. Verification is limited to the declared source and review scope. It does not mean independent replication or establish efficacy, safety, or suitability.