scholarly journals Long-range order from local interactions: organization and development of distributed cortical networks

2018 ◽  
Author(s):  
Gordon B. Smith ◽  
Bettina Hein ◽  
David E. Whitney ◽  
David Fitzpatrick ◽  
Matthias Kaschube

The cortical networks that underlie behavior exhibit an orderly functional organization at local and global scales, which is readily evident in the visual cortex of carnivores and primates1-6. Here, neighboring columns of neurons represent the full range of stimulus orientations and contribute to distributed networks spanning several millimeters2,7-11. However, the principles governing functional interactions that bridge this fine-scale functional architecture and distant network elements are unclear, and the emergence of these network interactions during development remains unexplored. Here, by using in vivo wide-field and 2-photon calcium imaging of spontaneous activity patterns in mature ferret visual cortex, we find widespread and specific modular correlation patterns that accurately predict the local structure of visually-evoked orientation columns from the spontaneous activity of neurons that lie several millimeters away. The large-scale networks revealed by correlated spontaneous activity show abrupt ‘fractures’ in continuity that are in tight register with evoked orientation pinwheels. Chronic in vivo imaging demonstrates that these large-scale modular correlation patterns and fractures are already present at early stages of cortical development and predictive of the mature network structure. Silencing feed-forward drive through either retinal or thalamic blockade does not affect network structure suggesting a cortical origin for this large-scale correlated activity, despite the immaturity of long-range horizontal network connections in the early cortex. Using a circuit model containing only local connections, we demonstrate that such a circuit is sufficient to generate large-scale correlated activity, while also producing correlated networks showing strong fractures, a reduced dimensionality, and an elongated local correlation structure, all in close agreement with our empirical data. These results demonstrate the precise local and global organization of cortical networks revealed through correlated spontaneous activity and suggest that local connections in early cortical circuits may generate structured long-range network correlations that underlie the subsequent formation of visually-evoked distributed functional networks.

2019 ◽  
Author(s):  
Paloma P Maldonado ◽  
Alvaro Nuno-Perez ◽  
Jan Kirchner ◽  
Elizabeth Hammock ◽  
Julijana Gjorgjieva ◽  
...  

SummarySpontaneous network activity shapes emerging neuronal circuits during early brain development, however how neuromodulation influences this activity is not fully understood. Here, we report that the neuromodulator oxytocin powerfully shapes spontaneous activity patterns. In vivo, oxytocin strongly decreased the frequency and pairwise correlations of spontaneous activity events in visual cortex (V1), but not in somatosensory cortex (S1). This differential effect was a consequence of oxytocin only increasing inhibition in V1 and increasing both inhibition and excitation in S1. The increase in inhibition was mediated by the depolarization and increase in excitability of somatostatin+ (SST) interneurons specifically. Accordingly, silencing SST+ neurons pharmacogenetically fully blocked oxytocin’s effect on inhibition in vitro as well its effect on spontaneous activity patterns in vivo. Thus, oxytocin decreases the excitatory/inhibitory ratio and modulates specific features of V1 spontaneous activity patterns that are crucial for refining developing synaptic connections and sensory processing later in life.


2021 ◽  
Author(s):  
Hadas Benisty ◽  
Andrew H Moberly ◽  
Sweyta Lohani ◽  
Daniel Barson ◽  
Ronald R Coifman ◽  
...  

Experimental work across a variety of species has demonstrated that spontaneously generated behaviors are robustly coupled to variation in neural activity within the cerebral cortex. Indeed, functional magnetic resonance imaging (fMRI) data suggest that functional connectivity in cortical networks varies across distinct behavioral states, providing for the dynamic reorganization of patterned activity. However, these studies generally lack the temporal resolution to establish links between cortical signals and the continuously varying fluctuations in spontaneous behavior typically observed in awake animals. Here, we took advantage of recent developments in wide-field, mesoscopic calcium imaging to monitor neural activity across the neocortex of awake mice. Applying a novel approach to quantifying time-varying functional connectivity, we show that spontaneous behaviors are more accurately represented by fast changes in the correlational structure versus the magnitude of large-scale network activity. Moreover, dynamic functional connectivity reveals subnetworks that are not predicted by traditional anatomical atlas-based parcellation of the cortex. These results provide insight into how behavioral information is represented across the mammalian neocortex and demonstrate a new analytical framework for investigating time-varying functional connectivity in neural networks.


2020 ◽  
Author(s):  
Marianne Groleau ◽  
Mojtaba Nazari-Ahangarkolaee ◽  
Matthieu P. Vanni ◽  
Jacqueline L. Higgins ◽  
Anne-Sophie Vézina Bédard ◽  
...  

AbstractAs the residual vision following a traumatic optic nerve injury can spontaneously recover over time, we explored the plasticity of cortical networks during the early post-optic nerve crush (ONC) phase. Using in vivo wide-field calcium imaging on awake Thy1-GCaMP6s mice, we characterized resting state and evoked cortical activity before, during, and 30 days after ONC. The recovery of monocular visual acuity and depth perception was evaluated at the same time points. Cortical responses to an LED flash decreased in the contralateral hemisphere in the primary visual cortex and in the secondary visual areas following the ONC, but was partially rescued between 3 and 5 days post-ONC, remaining stable thereafter. The connectivity between visual and non-visual regions was disorganized after the crush, as shown by a decorrelation, but correlated activity was restored 30 days after the injury. The number of surviving retinal ganglion cells dramatically dropped and remained low. At the behavioral level, the ONC resulted in visual acuity loss on the injured side and an increase in visual acuity with the non-injured eye. In conclusion, our results show a reorganization of connectivity between visual and associative cortical areas after an ONC, which is indicative of spontaneous cortical plasticity.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Marina E Wosniack ◽  
Jan H Kirchner ◽  
Ling-Ya Chao ◽  
Nawal Zabouri ◽  
Christian Lohmann ◽  
...  

Spontaneous activity drives the establishment of appropriate connectivity in different circuits during brain development. In the mouse primary visual cortex, two distinct patterns of spontaneous activity occur before vision onset: local low-synchronicity events originating in the retina and global high-synchronicity events originating in the cortex. We sought to determine the contribution of these activity patterns to jointly organize network connectivity through different activity-dependent plasticity rules. We postulated that local events shape cortical input selectivity and topography, while global events homeostatically regulate connection strength. However, to generate robust selectivity, we found that global events should adapt their amplitude to the history of preceding cortical activation. We confirmed this prediction by analyzing in vivo spontaneous cortical activity. The predicted adaptation leads to the sparsification of spontaneous activity on a slower timescale during development, demonstrating the remarkable capacity of the developing sensory cortex to acquire sensitivity to visual inputs after eye-opening.


2020 ◽  
Author(s):  
Kenta M Hagihara ◽  
Ayako Wendy Ishikawa ◽  
Yumiko Yoshimura ◽  
Yoshiaki Tagawa ◽  
Kenichi Ohki

Abstract Integration of information processed separately in distributed brain regions is essential for brain functions. This integration is enabled by long-range projection neurons, and further, concerted interactions between long-range projections and local microcircuits are crucial. It is not well known, however, how this interaction is implemented in cortical circuits. Here, to decipher this logic, using callosal projection neurons (CPNs) in layer 2/3 of the mouse visual cortex as a model of long-range projections, we found that CPNs exhibited distinct response properties and fine-scale local connectivity patterns. In vivo 2-photon calcium imaging revealed that CPNs showed a higher ipsilateral (to their somata) eye preference, and that CPN pairs showed stronger signal/noise correlation than random pairs. Slice recordings showed CPNs were preferentially connected to CPNs, demonstrating the existence of projection target-dependent fine-scale subnetworks. Collectively, our results suggest that long-range projection target predicts response properties and local connectivity of cortical projection neurons.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Marianne Groleau ◽  
Mojtaba Nazari-Ahangarkolaee ◽  
Matthieu P. Vanni ◽  
Jacqueline L. Higgins ◽  
Anne-Sophie Vézina Bédard ◽  
...  

AbstractAs the residual vision following a traumatic optic nerve injury can spontaneously recover over time, we explored the spontaneous plasticity of cortical networks during the early post-optic nerve crush (ONC) phase. Using in vivo wide-field calcium imaging on awake Thy1-GCaMP6s mice, we characterized resting state and evoked cortical activity before, during, and 31 days after ONC. The recovery of monocular visual acuity and depth perception was evaluated in parallel. Cortical responses to an LED flash decreased in the contralateral hemisphere in the primary visual cortex and in the secondary visual areas following the ONC, but was partially rescued between 3 and 5 days post-ONC, remaining stable thereafter. The connectivity between visual and non-visual regions was disorganized after the crush, as shown by a decorrelation, but correlated activity was restored 31 days after the injury. The number of surviving retinal ganglion cells dramatically dropped and remained low. At the behavioral level, the ONC resulted in visual acuity loss on the injured side and an increase in visual acuity with the non-injured eye. In conclusion, our results show a reorganization of connectivity between visual and associative cortical areas after an ONC, which is indicative of spontaneous cortical plasticity.


2008 ◽  
Vol 2008 ◽  
pp. 1-8 ◽  
Author(s):  
Atsushi Usami ◽  
Norio Matsuki ◽  
Yuji Ikegaya

Using functional multineuron imaging with single-cell resolution, we examined how hippocampal networks by themselves change the spatiotemporal patterns of spontaneous activity during the course of emitting spontaneous activity. When extracellular ionic concentrations were changed to those that mimicked in vivo conditions, spontaneous activity was increased in active cell number and activity frequency. When ionic compositions were restored to the control conditions, the activity level returned to baseline, but the weighted spatial dispersion of active cells, as assessed by entropy-based metrics, did not. Thus, the networks can modify themselves by altering the internal structure of their correlated activity, even though they as a whole maintained the same level of activity in space and time.


2020 ◽  
Author(s):  
Marina E. Wosniack ◽  
Jan H. Kirchner ◽  
Ling-Ya Chao ◽  
Nawal Zabouri ◽  
Christian Lohmann ◽  
...  

Spontaneous activity drives the establishment of appropriate connectivity in different circuits during brain development. In the mouse primary visual cortex, two distinct patterns of spontaneous activity occur before vision onset: local low-synchronicity events originating in the retina, and global high-synchronicity events originating in the cortex. We sought to determine the contribution of these activity patterns to jointly organize network connectivity through different activity-dependent plasticity rules. We found that local events shape cortical input selectivity and topography, while global events have a homeostatic role regulating connection strength. To generate robust selectivity, we predicted that global events should adapt their amplitude to the history of preceding cortical activation, and confirmed by analyzing in vivo spontaneous cortical activity. This adaptation led to the sparsification of spontaneous activity on a slower timescale during development, demonstrating the remarkable capacity of the developing sensory cortex to acquire sensitivity to visual inputs after eye-opening.


Sign in / Sign up

Export Citation Format

Share Document