Biology subjects

Kwon, S. E.

Publications and source records attributed to Kwon, S. E..

4 recordsLinked to original sources

bioRxiv2023

Learning-induced reorganization of neuronal subnetworks in the primary sensory cortex

Perceptual learning alters the representation of sensory input in primary sensory cortex. Alterations in neuronal tuning, correlation structure and population activity across many subcortical and cortical areas have been observed in previous studies. However, relationships between these different neural correlates - and to what extent they are relevant to specific perceptual tasks - are still unclear. In this study, we recorded activity of the layer 2/3 neuronal populations in the whisker primary somatosensory cortex (wS1) using in vivo two-photon calcium imaging as mice were trained to perform a self-initiated, whisker vibration frequency discrimination task. Individual wS1 neurons displayed learning-induced broadening of frequency sensitivity within task-related categories only during task performance, reflecting both learning-and context-dependent enhancement of category selectivity. Learning increased both signal and noise correlations within pairs of neurons that prefer the same stimulus category ( within-pool), whereas learning decreased neuronal correlations between neuron pairs that prefer different categories ( across-pool). Increased noise correlations in trained animals resulted in less accurate decoding of stimulus categories from population activity but did not affect decoding of the animals decision to respond to stimuli. Importantly, within-pool noise correlations were elevated on trials in which animals generated the learned behavioral response. We demonstrate that learning drives formation of task-relevant like-to-like layer 2/3 subnetworks in the primary sensory cortex that may facilitate execution of learned behavioral responses. Significance StatementWe found that cortical plasticity during perceptual learning alters both neuronal tuning and the structure of pairwise correlations such that they become increasingly aligned to task-related categories, indicating the formation of like-to-like subnetworks in layer 2/3 of sensory cortex. Category-specific increases in signal and noise correlations were induced by learning and only observed during active task performance, which points to top-down feedback as a driver of task-related subnetworks.

neuroscience↗

bioRxiv2022

Interneuron-targeted disruption of SYNGAP1 alters sensory representations in neocortex and impairs sensory learning

SYNGAP1 haploinsufficiency in humans results in severe neurodevelopmental disorders characterized by intellectual disability, autism, epilepsy, and sensory processing deficits. However, circuit mechanisms that underlie SYNGAP1-related neurodevelopmental disorders are poorly understood. A decrease of SynGAP in mice causes cognitive and behavioral deficits in part by disrupting the development of excitatory glutamatergic connections. Whether and to what extent SynGAP functions in inhibitory circuits remain unclear. We show that interneuron-specific SYNGAP1 heterozygous mice display learning deficits characterized by elevated behavioral responses in the absence of relevant sensory input and premature responses to a sensory input unrelated to reward acquisition. These behavioral deficits are associated with specific circuit abnormalities within primary somatosensory cortex, characterized by increased detrimental correlations and elevated responses to irrelevant sensory stimuli. Collectively, we show that a decrease of SynGAP in inhibitory interneurons disrupts sensory representation in the primary sensory cortex, which likely contributes to behavioral deficits.

neuroscience↗

bioRxiv2021

A cortico-cortical pathway targets inhibitory interneurons and modulates paw movement during locomotion in mice

The primary somatosensory cortex (S1) is important for the control of movement as it encodes sensory input from the body periphery and external environment during ongoing movement. Mouse S1 consists of several distinct sensorimotor subnetworks that receive topographically organized cortico-cortical inputs from distant sensorimotor areas, including the secondary somatosensory cortex (S2) and primary motor cortex (M1). The role of the vibrissal S1 area and associated cortical connections during active sensing is well documented, but whether (and if so, how) non-whisker S1 areas are involved in movement control remains relatively unexplored. Here, we demonstrate that unilateral silencing of the non-whisker S1 area in both male and female mice disrupts hind paw movement during locomotion on a rotarod and a runway. S2 and M1 provide major long-range inputs to this S1 area. Silencing S2 [->] non-whisker S1 projections alters the hind paw orientation during locomotion while manipulation of the M1 projection has little effect. Using patch-clamp recordings in brain slices from male and female mice, we show that S2 projection preferentially innervates inhibitory interneuron subtypes. We conclude that interneuron-mediated S2-S1 cortico-cortical interactions are critical for efficient locomotion. SignificanceSomatosensory cortex participates in controlling rhythmic movements such as whisking and walking, but the neural circuitry underlying movement control by somatosensory cortex remains relatively unexplored. We uncover a cortico-cortical circuit in primary somatosensory cortex that regulates paw orientation during locomotion in mice. We identify neuronal elements that comprise these cortical pathways using pharmacology, behavioral assays and circuit-mapping methods.

neuroscience↗

bioRxiv2019

Spectral Hallmark of Auditory-Tactile Interactions in Somatosensory Cortex

To synthesize a coherent representation of the external world, the brain must integrate inputs across stimulus modalities. Yet the mechanistic basis of this computation at the level of neuronal populations remains obscure. Here, we investigate tactile-auditory integration using two-photon Ca2+ imaging in the mouse primary (S1) and secondary (S2) somatosensory cortices. Pairing sound with whisker stimulation modulates tactile responses in both S1 and S2, with the most prominent modulation being robust inhibition in S2. The degree of inhibition depends on tactile stimulation frequency, with lower frequency responses the most severely attenuated. Alongside these neurons, we identify sound-selective neurons in S2 whose responses are inhibited by high tactile frequencies. These results are consistent with a hypothesized local mutually-inhibitory S2 circuit that spectrally selects tactile versus auditory inputs. Our findings enrich mechanistic understanding of multisensory integration and suggest a key role for S2 in combining auditory and tactile information.

neuroscience↗