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

Paradoxical response reversal of top-down modulation in cortical circuits with three interneuron types.

eLife · 2017

Study scale: Not reported in the declared source.

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

These findings, which have been further confirmed in a recent preprint (Dipoppa et al., 2017), appear to challenge the disinhibition hypothesis, suggesting that the nature of the interaction between VIP and SST could be stimulus dependent.

Study design

Not reported in the declared source.

Participants or experimental system

Pyramidal cells and interneurons expressing parvalbumin (PV), somatostatin (SST), and vasoactive intestinal peptide (VIP) show cell-type-specific connectivity patterns leading to a canonical microcircuit across cortex.

Study scale

Not reported in the declared source.

Intervention or exposure

This microcircuit motif, initially proposed theoretically (Wang et al., 2004), has been the subject of numerous recent experimental studies using optogenetic tools applied to behaving mice (Lee et al., 2012; Saleem et al., 2013; Kepecs and Fishell, 2014; Hawrylycz et al., 2016) as well as computational studies (Lee and Mihalas, 2015; Lee and Mihalas, 2017; Lee et al., 2017; Yang et al., 2016; Yang and Wang, 2017).

Comparator

Namely, in darkness the activation of VIP cells results in an average decrease of SST population activity (Fu et al., 2014), whereas in the presence of visual stimulation the response of SST cells is reversed and its firing rate increases during locomotion compared to immobility (Pakan et al., 2016).

Outcomes examined

A notable observation was that pyramidal neurons and VIP interneurons concomitantly increase their activities in the primary visual cortex V1 during locomotion in comparison with immobility (Niell and Stryker, 2010), even in the complete absence of visual input (Keller et al., 2012).

Key findings

Furthermore, we built a cortical circuit model which reproduces counterintuitive dynamics observed in mouse V1.

Limitations and uncertainty

Although this diversity can have many origins, such as intrinsic heterogeneity in the cells within the same class, we proposed that random connectivity alone is sufficient to explain it.

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.