Biology subjects

Kastner, S.

Publications and source records attributed to Kastner, S..

4 recordsLinked to original sources

bioRxiv2018

Pulvinar influences parietal delay activity and information transmission between dorsal and ventral visual cortex in macaques

The fronto-parietal attention network represents attentional priorities and provides feedback about these priorities to sensory cortical areas. Sustained spiking activity in the posterior parietal cortex (PPC) carries such prioritized information, but how this activity is sustained in the absence of feedforward sensory information, and how it is transmitted to the ventral visual cortical pathway, is unclear. We hypothesized that the higher-order thalamic nucleus, the pulvinar, which is connected with both the PPC and ventral visual cortical pathway, influences information transmission within and between these cortical regions. To test this, we simultaneously recorded from the pulvinar, lateral intraparietal area (LIP) and visual cortical area V4 in macaques performing a selective attention task. Here we show that LIP influenced V4 during the delay period of the attention task, and that the pulvinar regulated LIP-V4 information exchange. Pulvino-cortical effects were consistent with the pulvinar supporting sustained activity in LIP. Taken together, these results suggest that pulvinar regulation of cortical functional connectivity generalizes to dorsal and ventral visual cortical pathways. Further, the pulvinars role in sustaining parietal delay activity during selective attention implicates the pulvinar in other cognitive processes supported by such delay activity, including decision-making, categorization and oculomotor functions.\n\nSignificance StatementA network of areas on the brains surface, in frontal and parietal cortex, allocate attention to behaviorally relevant information around us. Such areas in parietal cortex show sustained activity during maintained attention and transmit behaviorally relevant information to visual cortical areas to enhance sensory processing of attended objects. How this activity is sustained and how it is transmitted to visual areas supporting object perception is unclear. We show that a subcortical area, the pulvinar in the thalamus, helps sustain activity in the cortex and regulates the information transmitted between the fronto-parietal attention network and visual cortex. This suggests that the thalamus, classically considered as a simple relay for sensory information, contributes to higher-level cognitive functions.

neuroscience↗

bioRxiv2018

Thalamo-cortical interactions define functional dissociations across the macaque attention network

Spatial attention is discontinuous, sampling behaviorally relevant locations in theta-rhythmic cycles (3-6 Hz). Underlying this rhythmic sampling are intrinsic theta oscillations in frontal and parietal cortices that provide a clocking mechanism for two alternating attentional states that are associated with either engagement at the presently attended location (and enhanced perceptual sensitivity) or disengagement (and diminished perceptual sensitivity). It has remained unclear, however, how these theta-dependent states are coordinated across the large-scale network that directs spatial attention. The pulvinar is a candidate for such coordination, having been previously shown to regulate cortical activity. We therefore examined pulvino-cortical interactions during theta-rhythmic sampling by simultaneously recording from FEF, LIP, and the pulvinar. Neural activity propagated from (i) pulvinar to cortex during periods of engagement and (ii) from cortex to pulvinar during periods of disengagement. A rhythmic reweighting of pulvino-cortical interactions thus defines functional dissociations in the macaque attention network.

neuroscience↗

bioRxiv2017

An open resource for nonhuman primate imaging

Non-human primate neuroimaging is a rapidly growing area of research that promises to transform and scale translational and cross-species comparative neuroscience.\n\nUnfortunately, the technological and methodological advances of the past two decades have outpaced the accrual of data, which is particularly challenging given the relatively few centers that have the necessary facilities and capabilities. The PRIMate Data Exchange (PRIME-DE) addresses this challenge by aggregating independently acquired non-human primate magnetic resonance imaging (MRI) datasets and openly sharing them via the International Neuroimaging Data-sharing Initiative (INDI). Here, we present the rationale, design and procedures for the PRIME-DE consortium, as well as the initial release, consisting of 13 independent data collections aggregated across 11 sites (total = 98 macaque monkeys). We also outline the unique pitfalls and challenges that should be considered in the analysis of the non-human primate MRI datasets, including providing automated quality assessment of the contributed datasets.

neuroscience↗

bioRxiv2017

Organizing principles of pulvino-cortical connectivity in humans

The pulvinar regulates information transmission to cortex and communication between cortical areas. The way the pulvinar interacts with cortex is governed by its intrinsic organization. Here, we show using fMRI that the human pulvinar is functionally heterogeneous, broadly separated into dorsal and ventral subdivisions based on characterization of response properties and functional connectivity with cortex. These differences mirrored the organization of the dorsal and ventral streams of visual cortex. The ventral subdivision of the pulvinar was functionally coupled with occipital and temporal cortex. The dorsal subdivision of the pulvinar was functionally coupled with frontal and parietal cortex. The dorsal subdivision was also coupled with the human-specific tool network and to the default mode network. The spatial organization of pulvino-cortical coupling reflected both the functional similarities and anatomical distances between cortical areas. Together, the human pulvinar appears to represent the entire visual system and the principles that govern its organization, though in a spatially compressed form.\n\nAuthor ContributionsMA, MP, and JC collected data; MA and JC analyzed the data; MA, MP, JC, and SK wrote the paper.

neuroscience↗