| 1. |
- Iurilli, Giuliano, et al.
(författare)
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Sound-Driven Synaptic Inhibition in Primary Visual Cortex
- 2012
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Ingår i: Neuron. - : Elsevier BV. - 0896-6273 .- 1097-4199. ; 73:4, s. 814-28
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Tidskriftsartikel (refereegranskat)abstract
- Multimodal objects and events activate many sensory cortical areas simultaneously. This is possibly reflected in reciprocal modulations of neuronal activity, even at the level of primary cortical areas. However, the synaptic character of these interareal interactions, and their impact on synaptic and behavioral sensory responses are unclear. Here, we found that activation of auditory cortex by a noise burst drove local GABAergic inhibition on supragranular pyramids of the mouse primary visual cortex, via cortico-cortical connections. This inhibition was generated by sound-driven excitation of a limited number of cells in infragranular visual cortical neurons. Consequently, visually driven synaptic and spike responses were reduced upon bimodal stimulation. Also, acoustic stimulation suppressed conditioned behavioral responses to a dim flash, an effect that was prevented by acute blockade of GABAergic transmission in visual cortex. Thus, auditory cortex activation by salient stimuli degrades potentially distracting sensory processing in visual cortex by recruiting local, translaminar, inhibitory circuits.
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| 2. |
- Olcese, Umberto, et al.
(författare)
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Cellular and synaptic architecture of multisensory integration in the mouse neocortex
- 2013
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Ingår i: Neuron. - : Elsevier BV. - 0896-6273 .- 1097-4199. ; 79:3, s. 579-593
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Tidskriftsartikel (refereegranskat)abstract
- Multisensory integration (MI) is crucial for sensory processing, but it is unclear how MI is organized in cortical microcircuits. Whole-cell recordings in a mouse visuotactile area located between primary visual and somatosensory cortices revealed that spike responses were less bimodal than synaptic responses but displayed larger multisensory enhancement. MI was layer and cell type specific, with multisensory enhancement being rare in the major class of inhibitory interneurons and in the output infragranular layers. Optogenetic manipulation of parvalbumin-positive interneuron activity revealed that the scarce MI of interneurons enables MI in neighboring pyramids. Finally, single-cell resolution calcium imaging revealed a gradual merging of modalities: unisensory neurons had higher densities toward the borders of the primary cortices, but were located in unimodal clusters in the middle of the cortical area. These findings reveal the role of different neuronal subcircuits in the synaptic process of MI in the rodent parietal cortex.
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