Author response: Clusters of synaptic inputs on dendrites of layer 5 pyramidal cells in mouse visual cortex

Cortical gamma oscillations have been implicated in a variety of cognitive, behavioral, and circuit-level phenomena. However, the circuit mechanisms of gamma-band generation and synchronization across cortical space remain uncertain. Using optogenetic patterned illumination in acute brain slices of mouse visual cortex, we define a circuit composed of layer 2/3 (L2/3) pyramidal cells and somatostatin (SOM) interneurons that phase-locks ensembles across the retinotopic map. The network oscillations generated here emerge from non-periodic stimuli, and are stimulus size-dependent, coherent across cortical space, narrow band (30 Hz), and depend on SOM neuron but not parvalbumin (PV) neuron activity; similar to visually induced gamma oscillations observed in vivo. Gamma oscillations generated in separate cortical locations exhibited high coherence as far apart as 850 μm, and lateral gamma entrainment depended on SOM neuron activity. These data identify a circuit that is sufficient to mediate long-range gamma-band coherence in the primary visual cortex.

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Pyramidal Cells Make Specific Connections onto Smooth (GABAergic) Neurons in Mouse Visual Cortex

PLoS Biology ◽

10.1371/journal.pbio.1001932 ◽

2014 ◽

Vol 12 (8) ◽

pp. e1001932 ◽

Cited By ~ 17

Author(s):

Rita Bopp ◽

Nuno Maçarico da Costa ◽

Björn M. Kampa ◽

Kevan A. C. Martin ◽

Morgane M. Roth

Keyword(s):

Visual Cortex ◽

Pyramidal Cells ◽

Gabaergic Neurons ◽

Mouse Visual Cortex

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Author response: Behavioral-state modulation of inhibition is context-dependent and cell type specific in mouse visual cortex

10.7554/elife.14985.013 ◽

2016 ◽

Cited By ~ 5

Author(s):

Janelle MP Pakan ◽

Scott C Lowe ◽

Evelyn Dylda ◽

Sander W Keemink ◽

Stephen P Currie ◽

...

Keyword(s):

Visual Cortex ◽

Author Response ◽

Behavioral State ◽

Cell Type ◽

Cell Type Specific ◽

Context Dependent ◽

Mouse Visual Cortex

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Opposing forms of adaptation in mouse visual cortex are controlled by distinct inhibitory microcircuits and gated by locomotion

10.1101/2020.01.16.909788 ◽

2020 ◽

Cited By ~ 1

Author(s):

Tristan G. Heintz ◽

Antonio J. Hinojosa ◽

Leon Lagnado

Keyword(s):

Visual Cortex ◽

Primary Visual Cortex ◽

Internal State ◽

Pyramidal Cells ◽

External World ◽

Neural Circuitry ◽

Cortical Processing ◽

Locomotor Behaviour ◽

Different Types ◽

Mouse Visual Cortex

SummaryCortical processing of sensory signals adjusts to changes in both the external world and the internal state of the animal. We investigated the neural circuitry by which these processes interact in the primary visual cortex of mice. An increase in contrast caused as many pyramidal cells (PCs) to sensitize as depress, reflecting the dynamics of adaptation in different types of interneuron (PV, SST and VIP). Optogenetic manipulations demonstrate that the net effect within PCs reflects the balance of PV inputs, driving depression, and a subset of SST interneurons, driving sensitization. Locomotor behaviour increased the gain of PC responses by disinhibition through both the VIP->SST and SST->PV pathways, thereby maintaining the balance between opposing forms of plasticity. These experiments reveal how inhibitory microcircuits interact to purpose different subsets of PCs for the signalling of increases or decreases in contrast while also allowing for behavioural control of gain across the population.

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Vision and locomotion shape the interactions between neuron types in mouse visual cortex

10.1101/058396 ◽

2016 ◽

Cited By ~ 13

Author(s):

Mario Dipoppa ◽

Adam Ranson ◽

Michael Krumin ◽

Marius Pachitariu ◽

Matteo Carandini ◽

...

Keyword(s):

Visual Cortex ◽

Pyramidal Cells ◽

Cell Types ◽

Synaptic Connectivity ◽

Cortical Function ◽

Cell Responses ◽

Layer 2 ◽

Measured Activity ◽

Sensory Responses ◽

Mouse Visual Cortex

SummaryIn the mouse primary visual cortex (V1), sensory responses are shaped by behavioral factors such as locomotion. These factors are thought to control a disinhibitory circuit, whereby interneurons expressing vasoactive intestinal peptide (Vip) inhibit those expressing somatostatin (Sst), disinhibiting pyramidal cells (Pyr). We measured the effect of locomotion on these neurons and on interneurons expressing parvalbumin (Pvalb) in layer 2/3 of mouse V1, and found in-consistencies with the disinhibitory model. In the presence of large stimuli, locomotion increased Sst cell responses without suppressing Vip cells. In the presence of small stimuli, locomotion increased Vip cell responses without suppressing Sst cells. A circuit model could reproduce each cell type’s activity from the measured activity of other cell types, but only if we allowed locomotion to increase feedforward synaptic weights while modulating recurrent weights. These results suggest that locomotion alters cortical function by changing effective synaptic connectivity, rather than only through disinhibition.

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Clusters of synaptic inputs on dendrites of layer 5 pyramidal cells in mouse visual cortex

eLife ◽

10.7554/elife.09222 ◽

2016 ◽

Vol 5 ◽

Cited By ~ 17

Author(s):

Onur Gökçe ◽

Tobias Bonhoeffer ◽

Volker Scheuss

Keyword(s):

Cortical Neurons ◽

Spatial Organization ◽

Dendritic Tree ◽

Pyramidal Cells ◽

Glutamatergic Synapses ◽

Dendritic Integration ◽

Synaptic Inputs ◽

Basal Dendrites ◽

Neural Computations ◽

Mouse Visual Cortex

The spatial organization of synaptic inputs on the dendritic tree of cortical neurons plays a major role for dendritic integration and neural computations, yet, remarkably little is known about it. We mapped the spatial organization of glutamatergic synapses between layer 5 pyramidal cells by combining optogenetics and 2-photon calcium imaging in mouse neocortical slices. To mathematically characterize the organization of inputs we developed an approach based on combinatorial analysis of the likelihoods of specific synapse arrangements. We found that the synapses of intralaminar inputs form clusters on the basal dendrites of layer 5 pyramidal cells. These clusters contain 4 to 14 synapses within ≤30 µm of dendrite. According to the spatiotemporal characteristics of synaptic summation, these numbers suggest that there will be non-linear dendritic integration of synaptic inputs during synchronous activation.

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