Biology subjects

Martin Vinck

Publications and source records attributed to Martin Vinck.

5 recordsLinked to original sources

bioRxiv2016

Developmental dysfunction of VIP interneurons impairs cortical circuits

Current evidence suggests that dysregulation of GABAergic interneurons contributes to neural and behavioral deficits in several neurodevelopmental disorders, including schizophrenia. However, there are multiple populations of interneurons and their respective roles in psychiatric disease remain poorly explored. Neuregulin 1 (NRG1) and its interneuron-specific tyrosine kinase receptor ERBB4 are risk genes for schizophrenia, and the Nrg1/ErbB4 pathway is important for normal cortical development. Using a conditional ErbB4 deletion model, we directly tested the role of vasoactive intestinal peptide (VIP)-expressing interneurons in schizophrenia-related deficits in vivo. ErbB4 removal from VIP interneurons during development leads to changes in their activity, along with severe dysregulation of the temporal organization and state-dependence of cortical activity. As a result of these neural circuit alterations, animals in which VIP interneurons lack ErbB4 exhibit behavioral abnormalities, reduced cortical responses to sensory stimuli, and impaired sensory learning. Our data support a key role for VIP interneurons in normal cortical circuit development and suggest that their disruption contributes to pathophysiology in the ErbB4 model of schizophrenia. These findings provide a new perspective on the role of GABAergic interneuron diversity in the disruption of cortical function in complex psychiatric diseases.

Neuroscience↗

bioRxiv2016

Altered hippocampal interneuron activity precedes ictal onset

Although failure of GABAergic inhibition is a commonly hypothesized mechanism underlying seizure disorders, the series of events that precipitate a rapid shift from healthy to ictal activity remain unclear. Furthermore, the diversity of inhibitory interneuron populations poses a challenge for understanding local circuit interactions during seizure initiation. Using a combined optogenetic and electrophysiological approach, we examined the activity of two identified hippocampal interneuron classes during seizure induction in vivo. We identified cell type-specific differences in preictal firing patterns and input sensitivity of parvalbumin- and somatostatin-expressing interneurons. Surprisingly, the impact of both sources of inhibition remained intact throughout the preictal period and into the early ictal phase. Our findings suggest that the onset of ictal activity is not due to a failure of inhibition, but is instead associated with a decoupling of inhibitory cells from their normal relationship with the local hippocampal network.

Neuroscience↗

bioRxiv2015

Cell-type and state-dependent synchronization among rodent areas S1BF, V1, perirhinal cortex and hippocampus CA1

Beta and gamma rhythms have been hypothesized to be involved in global and local coordination of neuronal activity, respectively. Here, we investigated how cells in rodent area S1BF are entrained by rhythmic fluctuations at various frequencies within the local area and in connected areas, and how this depends on behavioral state and cell type. We performed simultaneous extracellular field and unit recordings in four connected areas of the freely moving rat (S1BF, V1M, perirhinal cortex, CA1). S1BF spiking activity was strongly entrained by both beta and gamma S1BF oscillations, which were associated with deactivations and activations, respectively. We identified multiple classes of fast spiking and excitatory cells in S1BF, which showed prominent differences in rhythmic entrainment and in the extent to which phase locking was modulated by behavioral state. Using an additional dataset acquired by whole-cell recordings in head-fixed mice, these cell classes could be compared with identified phenotypes showing gamma rhythmicity in their membrane potential. We next examined how S1BF cells were entrained by rhythmic fluctuations in connected brain areas. Gamma-synchronization was detected in all four areas, however we did not detect significant gamma coherence among these areas. Instead, we only found long-range coherence in the theta-beta range among these areas. In contrast to local S1BF synchronization, we found long-range S1BF-spike to CA1-LFP synchronization to be homogeneous across inhibitory and excitatory cell types. These findings suggest distinct, cell-type contributions of low and high-frequency synchronization to intra- and inter-areal neuronal interactions.

Neuroscience↗

bioRxiv2015

Projection-specific visual feature encoding by layer 5 cortical subnetworks.

Primary neocortical sensory areas act as central hubs, distributing afferent information to numerous cortical and subcortical structures. However, it remains unclear whether each downstream target receives distinct versions of sensory information. We used in vivo calcium imaging combined with retrograde tracing to monitor visual response properties of three distinct subpopulations of projection neurons in primary visual cortex. While there is overlap across the groups, on average corticotectal (CT) cells exhibit lower contrast thresholds and broader tuning for orientation and spatial frequency in comparison to corticostriatal (CS) cells, while corticocortical (CC) cells have intermediate properties. Noise correlational analyses support the hypothesis that CT cells integrate information across diverse layer 5 populations, whereas CS and CC cells form more selectively interconnected groups. Overall, our findings demonstrate the existence of functional subnetworks within layer 5 that may differentially route visual information to behaviorally relevant downstream targets.

Neuroscience↗

bioRxiv2014

Arousal and locomotion make distinct contributions to cortical activity patterns and visual encoding

Spontaneous and sensory-evoked cortical activity is highly state-dependent, yet relatively little is known about transitions between distinct waking states. Patterns of activity in mouse V1 differ dramatically between quiescence and locomotion, but this difference could be explained by either motor feedback or a change in arousal levels. We recorded single cells and local field potentials from area V1 in mice head-fixed on a running wheel and monitored pupil diameter to assay arousal. Using naturally occurring and induced state transitions, we dissociated arousal and locomotion effects in V1. Arousal suppressed spontaneous firing and strongly altered the temporal patterning of population activity. Moreover, heightened arousal increased the signal-to-noise ratio of visual responses and reduced noise correlations. In contrast, increased firing in anticipation of and during movement was attributable to locomotion effects. Our findings suggest complementary roles of arousal and locomotion in promoting functional flexibility in cortical circuits.\n\nAbbreviations

Neuroscience↗