1
|
Suárez R, Bluett T, McCullough MH, Avitan L, Black DA, Paolino A, Fenlon LR, Goodhill GJ, Richards LJ. Cortical activity emerges in region-specific patterns during early brain development. Proc Natl Acad Sci U S A 2023; 120:e2208654120. [PMID: 37216522 PMCID: PMC10235933 DOI: 10.1073/pnas.2208654120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 04/17/2023] [Indexed: 05/24/2023] Open
Abstract
The development of precise neural circuits in the brain requires spontaneous patterns of neural activity prior to functional maturation. In the rodent cerebral cortex, patchwork and wave patterns of activity develop in somatosensory and visual regions, respectively, and are present at birth. However, whether such activity patterns occur in noneutherian mammals, as well as when and how they arise during development, remain open questions relevant for understanding brain formation in health and disease. Since the onset of patterned cortical activity is challenging to study prenatally in eutherians, here we offer an approach in a minimally invasive manner using marsupial dunnarts, whose cortex forms postnatally. We discovered similar patchwork and travelling waves in the dunnart somatosensory and visual cortices at stage 27 (equivalent to newborn mice) and examined earlier stages of development to determine the onset of these patterns and how they first emerge. We observed that these patterns of activity emerge in a region-specific and sequential manner, becoming evident as early as stage 24 in somatosensory and stage 25 in visual cortices (equivalent to embryonic day 16 and 17, respectively, in mice), as cortical layers establish and thalamic axons innervate the cortex. In addition to sculpting synaptic connections of existing circuits, evolutionarily conserved patterns of neural activity could therefore help regulate other early events in cortical development.
Collapse
Affiliation(s)
- Rodrigo Suárez
- The University of Queensland, Queensland Brain Institute, BrisbaneQLD4072, Australia
- The University of Queensland, School of Biomedical Sciences, BrisbaneQLD4072, Australia
| | - Tobias Bluett
- The University of Queensland, Queensland Brain Institute, BrisbaneQLD4072, Australia
| | - Michael H. McCullough
- The University of Queensland, Queensland Brain Institute, BrisbaneQLD4072, Australia
| | - Lilach Avitan
- The University of Queensland, Queensland Brain Institute, BrisbaneQLD4072, Australia
| | - Dylan A. Black
- The University of Queensland, Queensland Brain Institute, BrisbaneQLD4072, Australia
- The University of Queensland, School of Biomedical Sciences, BrisbaneQLD4072, Australia
| | - Annalisa Paolino
- The University of Queensland, Queensland Brain Institute, BrisbaneQLD4072, Australia
- The University of Queensland, School of Biomedical Sciences, BrisbaneQLD4072, Australia
| | - Laura R. Fenlon
- The University of Queensland, Queensland Brain Institute, BrisbaneQLD4072, Australia
- The University of Queensland, School of Biomedical Sciences, BrisbaneQLD4072, Australia
| | - Geoffrey J. Goodhill
- The University of Queensland, Queensland Brain Institute, BrisbaneQLD4072, Australia
- The University of Queensland, School of Mathematics and Physics, BrisbaneQLD4072, Australia
| | - Linda J. Richards
- The University of Queensland, Queensland Brain Institute, BrisbaneQLD4072, Australia
- The University of Queensland, School of Biomedical Sciences, BrisbaneQLD4072, Australia
| |
Collapse
|
2
|
Suárez R, Bluett T, McCullough MH, Avitan L, Black DA, Paolino A, Fenlon LR, Goodhill GJ, Richards LJ. Cortical activity emerges in region-specific patterns during early brain development. bioRxiv 2023:2023.02.18.529078. [PMID: 36824827 PMCID: PMC9949140 DOI: 10.1101/2023.02.18.529078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
The development of precise neural circuits in the brain requires spontaneous patterns of neural activity prior to functional maturation. In the rodent cerebral cortex patchwork and wave patterns of activity develop in somatosensory and visual regions, respectively, and are present at birth. However, whether such activity patterns occur in non-eutherian mammals, as well as when and how they arise during development remain open questions relevant to understand brain formation in health and disease. Since the onset of patterned cortical activity is challenging to study prenatally in eutherians, here we offer a new approach in a minimally invasive manner using marsupial dunnarts, whose cortex forms postnatally. We discovered similar patchwork and travelling waves in the dunnart somatosensory and visual cortices at stage 27 (equivalent to newborn mice), and examined progressively earlier stages of development to determine their onset and how they first emerge. We observed that these patterns of activity emerge in a region-specific and sequential manner, becoming evident as early as stage 24 in somatosensory and stage 25 in visual cortices (equivalent to embryonic day 16 and 17, respectively, in mice), as cortical layers establish and thalamic axons innervate the cortex. In addition to sculpting synaptic connections of existing circuits, evolutionarily conserved patterns of neural activity could therefore help regulate early events in cortical development. Significance Statement Region-specific patterns of neural activity are present at birth in rodents and are thought to refine synaptic connections during critical periods of cerebral cortex development. Marsupials are born much more immature than rodents, allowing the investigation of how these patterns arise in vivo. We discovered that cortical activity patterns are remarkably similar in marsupial dunnarts and rodents, and that they emerge very early, before cortical neurogenesis is complete. Moreover, they arise from the outset in different patterns specific to somatosensory and visual areas (i.e., patchworks and waves) indicating they may also play evolutionarily conserved roles in cortical regionalization during development.
Collapse
Affiliation(s)
- Rodrigo Suárez
- The University of Queensland, Queensland Brain Institute; Brisbane, Australia
- The University of Queensland, School of Biomedical Sciences; Brisbane, Australia
| | - Tobias Bluett
- The University of Queensland, Queensland Brain Institute; Brisbane, Australia
| | | | - Lilach Avitan
- The University of Queensland, Queensland Brain Institute; Brisbane, Australia
| | - Dylan A. Black
- The University of Queensland, Queensland Brain Institute; Brisbane, Australia
- The University of Queensland, School of Biomedical Sciences; Brisbane, Australia
| | - Annalisa Paolino
- The University of Queensland, Queensland Brain Institute; Brisbane, Australia
- The University of Queensland, School of Biomedical Sciences; Brisbane, Australia
| | - Laura R. Fenlon
- The University of Queensland, Queensland Brain Institute; Brisbane, Australia
- The University of Queensland, School of Biomedical Sciences; Brisbane, Australia
| | - Geoffrey J. Goodhill
- The University of Queensland, Queensland Brain Institute; Brisbane, Australia
- The University of Queensland, School of Mathematics and Physics; Brisbane, Australia
| | - Linda J. Richards
- The University of Queensland, Queensland Brain Institute; Brisbane, Australia
- The University of Queensland, School of Biomedical Sciences; Brisbane, Australia
| |
Collapse
|
3
|
Zhu SI, McCullough MH, Pujic Z, Sibberas J, Sun B, Darveniza T, Bucknall B, Avitan L, Goodhill GJ. fmr1 Mutation Alters the Early Development of Sensory Coding and Hunting and Social Behaviors in Larval Zebrafish. J Neurosci 2023; 43:1211-1224. [PMID: 36596699 PMCID: PMC9962781 DOI: 10.1523/jneurosci.1721-22.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 12/16/2022] [Accepted: 12/20/2022] [Indexed: 01/05/2023] Open
Abstract
Autism spectrum disorders (ASDs) are developmental in origin; however, little is known about how they affect the early development of behavior and sensory coding. The most common inherited form of autism is Fragile X syndrome (FXS), caused by a mutation in FMR1 Mutation of fmr1 in zebrafish causes anxiety-like behavior, hyperactivity, and hypersensitivity in auditory and visual processing. Here, we show that zebrafish fmr1-/- mutant larvae of either sex also display changes in hunting behavior, tectal coding, and social interaction. During hunting, they were less successful at catching prey and displayed altered behavioral sequences. In the tectum, representations of prey-like stimuli were more diffuse and had higher dimensionality. In a social behavioral assay, they spent more time observing a conspecific but responded more slowly to social cues. However, when given a choice of rearing environment fmr1-/- larvae preferred one with reduced visual stimulation, and rearing them in this environment reduced genotype-specific effects on tectal excitability. Together, these results shed new light on how fmr1-/- changes the early development of neural systems and behavior in a vertebrate.SIGNIFICANCE STATEMENT Autism spectrum disorders (ASDs) are caused by changes in early neural development. Animal models of ASDs offer the opportunity to study these developmental processes in greater detail than in humans. Here, we found that a zebrafish mutant for a gene which in humans causes one type of ASD showed early alterations in hunting behavior, social behavior, and how visual stimuli are represented in the brain. However, we also found that mutant fish preferred reduced visual stimulation, and rearing them in this environment reduced alterations in neural activity patterns. These results suggest interesting new directions for using zebrafish as a model to study the development of brain and behavior in ASDs, and how the impact of ASDs could potentially be reduced.
Collapse
Affiliation(s)
- Shuyu I Zhu
- Queensland Brain Institute
- Departments of Developmental Biology and Neuroscience, Washington University in St. Louis, St. Louis, Missouri 63110
| | | | | | | | | | - Thomas Darveniza
- Departments of Developmental Biology and Neuroscience, Washington University in St. Louis, St. Louis, Missouri 63110
| | | | | | - Geoffrey J Goodhill
- Queensland Brain Institute
- School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland 4072, Australia
- Departments of Developmental Biology and Neuroscience, Washington University in St. Louis, St. Louis, Missouri 63110
| |
Collapse
|
4
|
Avitan L, Stringer C. Not so spontaneous: Multi-dimensional representations of behaviors and context in sensory areas. Neuron 2022; 110:3064-3075. [PMID: 35863344 DOI: 10.1016/j.neuron.2022.06.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/20/2022] [Accepted: 06/22/2022] [Indexed: 11/27/2022]
Abstract
Sensory areas are spontaneously active in the absence of sensory stimuli. This spontaneous activity has long been studied; however, its functional role remains largely unknown. Recent advances in technology, allowing large-scale neural recordings in the awake and behaving animal, have transformed our understanding of spontaneous activity. Studies using these recordings have discovered high-dimensional spontaneous activity patterns, correlation between spontaneous activity and behavior, and dissimilarity between spontaneous and sensory-driven activity patterns. These findings are supported by evidence from developing animals, where a transition toward these characteristics is observed as the circuit matures, as well as by evidence from mature animals across species. These newly revealed characteristics call for the formulation of a new role for spontaneous activity in neural sensory computation.
Collapse
Affiliation(s)
- Lilach Avitan
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of Jerusalem, Jerusalem 9190401, Israel.
| | | |
Collapse
|
5
|
Abstract
The immature brain is highly spontaneously active. Over development this activity must be integrated with emerging patterns of stimulus-evoked activity, but little is known about how this occurs. Here we investigated this question by recording spontaneous and evoked neural activity in the larval zebrafish tectum from 4 to 15 days post-fertilisation. Correlations within spontaneous and evoked activity epochs were comparable over development, and their neural assemblies refined in similar ways. However, both the similarity between evoked and spontaneous assemblies, and also the geometric distance between spontaneous and evoked patterns, decreased over development. At all stages of development, evoked activity was of higher dimension than spontaneous activity. Thus, spontaneous and evoked activity do not converge over development in this system, and these results do not support the hypothesis that spontaneous activity evolves to form a Bayesian prior for evoked activity.
Collapse
Affiliation(s)
- Lilach Avitan
- Queensland Brain Institute, The University of QueenslandBrisbaneAustralia
- Edmond and Lily Safra Center for Brain Sciences, The Hebrew University of JerusalemJerusalemIsrael
| | - Zac Pujic
- Queensland Brain Institute, The University of QueenslandBrisbaneAustralia
| | - Jan Mölter
- Queensland Brain Institute, The University of QueenslandBrisbaneAustralia
- School of Mathematics and Physics, The University of QueenslandBrisbaneAustralia
| | - Shuyu Zhu
- Queensland Brain Institute, The University of QueenslandBrisbaneAustralia
| | - Biao Sun
- Queensland Brain Institute, The University of QueenslandBrisbaneAustralia
| | - Geoffrey J Goodhill
- Queensland Brain Institute, The University of QueenslandBrisbaneAustralia
- School of Mathematics and Physics, The University of QueenslandBrisbaneAustralia
| |
Collapse
|
6
|
Triplett MA, Pujic Z, Sun B, Avitan L, Goodhill GJ. Model-based decoupling of evoked and spontaneous neural activity in calcium imaging data. PLoS Comput Biol 2020; 16:e1008330. [PMID: 33253161 PMCID: PMC7728401 DOI: 10.1371/journal.pcbi.1008330] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 12/10/2020] [Accepted: 09/10/2020] [Indexed: 11/19/2022] Open
Abstract
The pattern of neural activity evoked by a stimulus can be substantially affected by ongoing spontaneous activity. Separating these two types of activity is particularly important for calcium imaging data given the slow temporal dynamics of calcium indicators. Here we present a statistical model that decouples stimulus-driven activity from low dimensional spontaneous activity in this case. The model identifies hidden factors giving rise to spontaneous activity while jointly estimating stimulus tuning properties that account for the confounding effects that these factors introduce. By applying our model to data from zebrafish optic tectum and mouse visual cortex, we obtain quantitative measurements of the extent that neurons in each case are driven by evoked activity, spontaneous activity, and their interaction. By not averaging away potentially important information encoded in spontaneous activity, this broadly applicable model brings new insight into population-level neural activity within single trials.
Collapse
Affiliation(s)
- Marcus A. Triplett
- Queensland Brain Institute, The University of Queensland, St Lucia, Australia
- School of Mathematics and Physics, The University of Queensland, St Lucia, Australia
| | - Zac Pujic
- Queensland Brain Institute, The University of Queensland, St Lucia, Australia
| | - Biao Sun
- Queensland Brain Institute, The University of Queensland, St Lucia, Australia
| | - Lilach Avitan
- Queensland Brain Institute, The University of Queensland, St Lucia, Australia
| | - Geoffrey J. Goodhill
- Queensland Brain Institute, The University of Queensland, St Lucia, Australia
- School of Mathematics and Physics, The University of Queensland, St Lucia, Australia
| |
Collapse
|
7
|
Avitan L, Pujic Z, Mölter J, McCullough M, Zhu S, Sun B, Myhre AE, Goodhill GJ. Behavioral Signatures of a Developing Neural Code. Curr Biol 2020; 30:3352-3363.e5. [DOI: 10.1016/j.cub.2020.06.040] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 04/13/2020] [Accepted: 06/11/2020] [Indexed: 10/23/2022]
|
8
|
Mölter J, Avitan L, Goodhill GJ. Correction to: Detecting neural assemblies in calcium imaging data. BMC Biol 2019; 17:21. [PMID: 30841881 PMCID: PMC6404314 DOI: 10.1186/s12915-019-0644-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 02/15/2019] [Indexed: 11/10/2022] Open
|
9
|
Abstract
BACKGROUND Activity in populations of neurons often takes the form of assemblies, where specific groups of neurons tend to activate at the same time. However, in calcium imaging data, reliably identifying these assemblies is a challenging problem, and the relative performance of different assembly-detection algorithms is unknown. RESULTS To test the performance of several recently proposed assembly-detection algorithms, we first generated large surrogate datasets of calcium imaging data with predefined assembly structures and characterised the ability of the algorithms to recover known assemblies. The algorithms we tested are based on independent component analysis (ICA), principal component analysis (Promax), similarity analysis (CORE), singular value decomposition (SVD), graph theory (SGC), and frequent item set mining (FIM-X). When applied to the simulated data and tested against parameters such as array size, number of assemblies, assembly size and overlap, and signal strength, the SGC and ICA algorithms and a modified form of the Promax algorithm performed well, while PCA-Promax and FIM-X did less well, for instance, showing a strong dependence on the size of the neural array. Notably, we identified additional analyses that can improve their importance. Next, we applied the same algorithms to a dataset of activity in the zebrafish optic tectum evoked by simple visual stimuli, and found that the SGC algorithm recovered assemblies closest to the averaged responses. CONCLUSIONS Our findings suggest that the neural assemblies recovered from calcium imaging data can vary considerably with the choice of algorithm, but that some algorithms reliably perform better than others. This suggests that previous results using these algorithms may need to be reevaluated in this light.
Collapse
Affiliation(s)
- Jan Mölter
- Queensland Brian Institute, The University of Queensland, Brisbane, 4072, Australia.,School of Mathematics and Physics, The University of Queensland, Brisbane, 4072, Australia
| | - Lilach Avitan
- Queensland Brian Institute, The University of Queensland, Brisbane, 4072, Australia
| | - Geoffrey J Goodhill
- Queensland Brian Institute, The University of Queensland, Brisbane, 4072, Australia. .,School of Mathematics and Physics, The University of Queensland, Brisbane, 4072, Australia.
| |
Collapse
|
10
|
Triplett MA, Avitan L, Goodhill GJ. Emergence of spontaneous assembly activity in developing neural networks without afferent input. PLoS Comput Biol 2018; 14:e1006421. [PMID: 30265665 PMCID: PMC6161857 DOI: 10.1371/journal.pcbi.1006421] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 08/07/2018] [Indexed: 02/04/2023] Open
Abstract
Spontaneous activity is a fundamental characteristic of the developing nervous system. Intriguingly, it often takes the form of multiple structured assemblies of neurons. Such assemblies can form even in the absence of afferent input, for instance in the zebrafish optic tectum after bilateral enucleation early in life. While the development of neural assemblies based on structured afferent input has been theoretically well-studied, it is less clear how they could arise in systems without afferent input. Here we show that a recurrent network of binary threshold neurons with initially random weights can form neural assemblies based on a simple Hebbian learning rule. Over development the network becomes increasingly modular while being driven by initially unstructured spontaneous activity, leading to the emergence of neural assemblies. Surprisingly, the set of neurons making up each assembly then continues to evolve, despite the number of assemblies remaining roughly constant. In the mature network assembly activity builds over several timesteps before the activation of the full assembly, as recently observed in calcium-imaging experiments. Our results show that Hebbian learning is sufficient to explain the emergence of highly structured patterns of neural activity in the absence of structured input.
Collapse
Affiliation(s)
- Marcus A. Triplett
- Queensland Brain Institute, University of Queensland, St Lucia, Queensland, Australia
- School of Mathematics and Physics, University of Queensland, St Lucia, Queensland, Australia
| | - Lilach Avitan
- Queensland Brain Institute, University of Queensland, St Lucia, Queensland, Australia
| | - Geoffrey J. Goodhill
- Queensland Brain Institute, University of Queensland, St Lucia, Queensland, Australia
- School of Mathematics and Physics, University of Queensland, St Lucia, Queensland, Australia
- * E-mail:
| |
Collapse
|
11
|
Avitan L, Goodhill GJ. Code Under Construction: Neural Coding Over Development. Trends Neurosci 2018; 41:599-609. [DOI: 10.1016/j.tins.2018.05.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/17/2018] [Accepted: 05/25/2018] [Indexed: 01/11/2023]
|
12
|
Marachlian E, Avitan L, Goodhill GJ, Sumbre G. Principles of Functional Circuit Connectivity: Insights From Spontaneous Activity in the Zebrafish Optic Tectum. Front Neural Circuits 2018; 12:46. [PMID: 29977193 PMCID: PMC6021757 DOI: 10.3389/fncir.2018.00046] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/28/2018] [Indexed: 02/06/2023] Open
Abstract
The brain is continuously active, even in the absence of external stimulation. In the optic tectum of the zebrafish larva, this spontaneous activity is spatially organized and reflects the circuit's functional connectivity. The structure of the spontaneous activity displayed patterns associated with aspects of the larva's preferences when engaging in complex visuo-motor behaviors, suggesting that the tectal circuit is adapted for the circuit's functional role in detecting visual cues and generating adequate motor behaviors. Further studies in sensory deprived larvae suggest that the basic structure of the functional connectivity patterns emerges even in the absence of retinal inputs, but that its fine structure is affected by visual experience.
Collapse
Affiliation(s)
- Emiliano Marachlian
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Université Paris, Paris, France
| | - Lilach Avitan
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Geoffrey J Goodhill
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia.,School of Mathematics and Physics, The University of Queensland, Brisbane, QLD, Australia
| | - Germán Sumbre
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Université Paris, Paris, France
| |
Collapse
|
13
|
Avitan L, Pujic Z, Mölter J, Van De Poll M, Sun B, Teng H, Amor R, Scott EK, Goodhill GJ. Spontaneous Activity in the Zebrafish Tectum Reorganizes over Development and Is Influenced by Visual Experience. Curr Biol 2017; 27:2407-2419.e4. [PMID: 28781054 DOI: 10.1016/j.cub.2017.06.056] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 05/18/2017] [Accepted: 06/20/2017] [Indexed: 10/19/2022]
Abstract
Spontaneous patterns of activity in the developing visual system may play an important role in shaping the brain for function. During the period 4-9 dpf (days post-fertilization), larval zebrafish learn to hunt prey, a behavior that is critically dependent on the optic tectum. However, how spontaneous activity develops in the tectum over this period and the effect of visual experience are unknown. Here we performed two-photon calcium imaging of GCaMP6s zebrafish larvae at all days from 4 to 9 dpf. Using recently developed graph theoretic techniques, we found significant changes in both single-cell and population activity characteristics over development. In particular, we identified days 5-6 as a critical moment in the reorganization of the underlying functional network. Altering visual experience early in development altered the statistics of tectal activity, and dark rearing also caused a long-lasting deficit in the ability to capture prey. Thus, tectal development is shaped by both intrinsic factors and visual experience.
Collapse
Affiliation(s)
- Lilach Avitan
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Zac Pujic
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Jan Mölter
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia; School of Mathematics and Physics, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Matthew Van De Poll
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Biao Sun
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Haotian Teng
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Rumelo Amor
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Ethan K Scott
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia; School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Geoffrey J Goodhill
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia; School of Mathematics and Physics, The University of Queensland, Brisbane, QLD 4072, Australia.
| |
Collapse
|
14
|
Suárez R, Fenlon LR, Marek R, Avitan L, Sah P, Goodhill GJ, Richards LJ. Balanced interhemispheric cortical activity is required for correct targeting of the corpus callosum. Neuron 2014; 82:1289-98. [PMID: 24945772 DOI: 10.1016/j.neuron.2014.04.040] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/23/2014] [Indexed: 10/25/2022]
Abstract
Bilateral integration of sensory and associative brain processing is achieved by precise connections between homologous regions in the two hemispheres via the corpus callosum. These connections form postnatally, and unilateral deprivation of sensory or spontaneous cortical activity during a critical period severely disrupts callosal wiring. However, little is known about how this early activity affects precise circuit formation. Here, using in utero electroporation of reporter genes, optogenetic constructs, and direct disruption of activity in callosal neurons combined with whisker ablations, we show that balanced interhemispheric activity, and not simply intact cortical activity in either hemisphere, is required for functional callosal targeting. Moreover, bilateral ablation of whiskers in symmetric or asymmetric configurations shows that spatially symmetric interhemispheric activity is required for appropriate callosal targeting. Our findings reveal a principle governing axon targeting, where spatially balanced activity between regions is required to establish their appropriate connectivity.
Collapse
Affiliation(s)
- Rodrigo Suárez
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Laura R Fenlon
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Roger Marek
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Lilach Avitan
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Pankaj Sah
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia; School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Geoffrey J Goodhill
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia; School of Mathematics and Physics, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Linda J Richards
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia; School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia.
| |
Collapse
|
15
|
Abstract
EEG generator-a model of potentials in a volume conductor. The potential recorded over the cortex electro-corticogram (ECoG) or over the scalp [electroencephalograph (EEG)] derives from the activity of many sources known as "EEG generators." The recorded amplitude is basically a function of the unitary potential of a generator and the statistical relationship between different EEG generators in the recorded population. In this study, we first suggest a new definition of the EEG generator. We use the theory of potentials in a volume conductor and model the contribution of a single synapse activated to the surface potential. We then model the contribution of the generator to the surface potential. Once the generator and its contribution are well defined, we can quantitatively assess the degree of synchronization among generators. The measures obtained by the model for a real life scenario of a group of generators organized in a specific statistical way were consistent with the expected values that were reported experimentally. The study sheds new light on macroscopic modeling approaches which make use of mean soma membrane potential. We showed major contribution of activity of superficial apical synapses to the ECoG signal recorded relative to lower somatic or basal synapses activity.
Collapse
Affiliation(s)
- Lilach Avitan
- The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan 52900, Israel.
| | | | | |
Collapse
|
16
|
Avitan L, Teicher M, Abeles M. Resolving the dynamics of EEG generators by multichannel recordings. Biol Cybern 2008; 98:49-59. [PMID: 18060561 DOI: 10.1007/s00422-007-0192-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2007] [Accepted: 10/08/2007] [Indexed: 05/25/2023]
Abstract
The voltage recorded over the cortex (ECoG) or over the scalp (EEG) is generated by currents derived from many sources called "generators". Different patterns and amplitudes are observed in aroused, sleepy, epileptic or other brain states. Differences in amplitude are generally attributed to differences in synchrony among generators. The degree of EEG synchrony is measured by the correlation between electrodes placed over different cortical regions. We present a new way to quantitatively assess the degree of synchronization of these generators via multichannel recordings. We illustrate how situations where there are several groups of generators with different inter-group and intra-group synchronies can be analyzed. Finally, we present a way to identify the organization of groups exhibiting topographic organization. Although the model presented here is highly simplified, several methods are based on averaging activity over increasingly larger areas. These types of measurements may be applied as well to EEG and ECoG recordings.
Collapse
Affiliation(s)
- Lilach Avitan
- Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, 52900, Israel.
| | | | | |
Collapse
|