A brainstem integrator for self-localization and positional homeostasis

To accurately track self-location, animals need to integrate their movements through space. In amniotes, representations of self-location have been found in regions such as the hippocampus. It is unknown whether more ancient brain regions contain such representations and by which pathways they may drive locomotion. Fish displaced by water currents must prevent uncontrolled drift to potentially dangerous areas. We found that larval zebrafish track such movements and can later swim back to their earlier location. Whole-brain functional imaging revealed the circuit enabling this process of positional homeostasis. Position-encoding brainstem neurons integrate optic flow, then bias future swimming to correct for past displacements by modulating inferior olive and cerebellar activity. Manipulation of position-encoding or olivary neurons abolished positional homeostasis or evoked behavior as if animals had experienced positional shifts. These results reveal a multiregional hindbrain circuit in vertebrates for optic flow integration, memory of self-location, and its neural pathway to behavior.

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Whole-brain calcium imaging during physiological vestibular stimulation in larval zebrafish

10.1101/300350 ◽

2018 ◽

Author(s):

Geoffrey Migault ◽

Thomas Panier ◽

Raphaël Candelier ◽

Georges Debrégeas ◽

Volker Bormuth

Keyword(s):

Virtual Environments ◽

Functional Imaging ◽

Light Sheet ◽

Vestibular Stimulation ◽

Brain Response ◽

Whole Brain ◽

Larval Zebrafish ◽

In Vivo Functional Imaging ◽

First Time

AbstractDuring in vivo functional imaging, animals are head-fixed and thus deprived from vestibular inputs, which severely hampers the design of naturalistic virtual environments. To overcome this limitation, we developed a miniaturized ultra-stable light-sheet microscope that can be dynamically rotated during imaging along with a head-restrained zebrafish larva. We demonstrate that this system enables whole-brain functional imaging at single-cell resolution under controlled vestibular stimulation. We recorded for the first time the dynamic whole-brain response of a vertebrate to physiological vestibular stimulation. This development largely expands the potential of virtual-reality systems to explore complex multisensory-motor integration in 3D.

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Mapping whole-brain seizure network recruitment with optogenetic kindling

Journal of Neurophysiology ◽

10.1152/jn.00525.2021 ◽

2022 ◽

Author(s):

James Edward Niemeyer

Keyword(s):

Functional Imaging ◽

Epileptic Seizures ◽

Brain Regions ◽

Brain Dynamics ◽

Cell Type ◽

Whole Brain ◽

Common View ◽

Cell Type Specific

Epilepsy is often labelled a network disorder, though a common view of seizures holds that they initiate in a singular onset zone before expanding contiguously outward. A recent report by Choy et al. (2021) leverages new tools to study whole-brain dynamics during epileptic seizures originating in the hippocampus. Cell-type-specific kindling and functional imaging revealed how various brain regions were recruited to seizures and uncovered a novel form of migrating seizure core.

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Rapid whole brain imaging of neural activity in freely behaving larval zebrafish (Danio rerio)

10.1101/131532 ◽

2017 ◽

Cited By ~ 1

Author(s):

Lin Cong ◽

Zeguan Wang ◽

Yuming Chai ◽

Wei Hang ◽

Chunfeng Shang ◽

...

Keyword(s):

Functional Imaging ◽

Danio Rerio ◽

Neural Activity ◽

Prey Capture ◽

Brain Dynamics ◽

3D Tracking ◽

Whole Brain ◽

Larval Zebrafish ◽

Volume Imaging ◽

Freely Behaving

AbstractThe internal brain dynamics that link sensation and action are arguably better studied during natural animal behaviors. Here we report on a novel volume imaging and 3D tracking technique that monitors whole brain neural activity in freely swimming larval zebrafish (Danio rerio). We demonstrated the capability of our system through functional imaging of neural activity during visually evoked and prey capture behaviors in larval zebrafish.

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Rapid whole brain imaging of neural activity in freely behaving larval zebrafish (Danio rerio)

eLife ◽

10.7554/elife.28158 ◽

2017 ◽

Vol 6 ◽

Cited By ~ 82

Author(s):

Lin Cong ◽

Zeguan Wang ◽

Yuming Chai ◽

Wei Hang ◽

Chunfeng Shang ◽

...

Keyword(s):

Functional Imaging ◽

Danio Rerio ◽

Neural Activity ◽

Prey Capture ◽

Brain Dynamics ◽

3D Tracking ◽

Whole Brain ◽

Larval Zebrafish ◽

Volume Imaging ◽

Freely Behaving

The internal brain dynamics that link sensation and action are arguably better studied during natural animal behaviors. Here, we report on a novel volume imaging and 3D tracking technique that monitors whole brain neural activity in freely swimming larval zebrafish (Danio rerio). We demonstrated the capability of our system through functional imaging of neural activity during visually evoked and prey capture behaviors in larval zebrafish.

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Conceptual disorganization and redistribution of resting state cortical hubs in untreated first episode psychosis: A 7T MRI study

10.31234/osf.io/rzvby ◽

2020 ◽

Author(s):

Avyarthana Dey ◽

Kara Dempster ◽

Michael Mackinley ◽

Peter Jeon ◽

Tushar Das ◽

...

Keyword(s):

Negative Symptoms ◽

Superior Temporal Gyrus ◽

Brain Regions ◽

First Episode Psychosis ◽

Cortical Reorganization ◽

First Episode ◽

Formal Thought Disorder ◽

Whole Brain ◽

Episode Psychosis ◽

Positive And Negative Symptoms

Background:Network level dysconnectivity has been studied in positive and negative symptoms of schizophrenia. Conceptual disorganization (CD) is a symptom subtype which predicts impaired real-world functioning in psychosis. Systematic reviews have reported aberrant connectivity in formal thought disorder, a construct related to CD. However, no studies have investigated whole-brain functional correlates of CD in psychosis. We sought to investigate brain regions explaining the severity of CD in patients with first-episode psychosis (FEPs) compared with healthy controls (HCs).Methods:We computed whole-brain binarized degree centrality maps of 31 FEPs, 25 HCs and characterized the patterns of network connectivity in the two groups. In FEPs, we related these findings to the severity of CD. We also studied the effect of positive and negative symptoms on altered network connectivity.Results:Compared to HCs, reduced hubness of a right superior temporal gyrus (rSTG) cluster was observed in the FEPs. In patients exhibiting high CD, increased hubness of a medial superior parietal (mSPL) cluster was observed, compared to patients exhibiting low CD. These two regions were strongly correlated with CD scores but not with other symptom scores.Discussion:Our observations are congruent with previous findings of reduced but not increased hubness. We observed increased hubness of mSPL suggesting that cortical reorganization occurs to provide alternate routes for information transfer.Conclusion:These findings provide insight into the underlying neural processes mediating the presentation of symptoms in untreated FEP. A longitudinal tracking of the symptom course will be useful to assess the mechanisms underlying these compensatory changes.

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Cerebrovascular responses of the rat brain to noxious stimuli as examined by functional near-infrared whole brain imaging

Journal of Neurophysiology ◽

10.1152/jn.00050.2011 ◽

2012 ◽

Vol 107 (10) ◽

pp. 2853-2865 ◽

Cited By ~ 6

Author(s):

Ji-Wei He ◽

Fenghua Tian ◽

Hanli Liu ◽

Yuan Bo Peng

Keyword(s):

Brain Imaging ◽

Near Infrared ◽

Small Animal ◽

Nir Spectroscopy ◽

Brain Regions ◽

Anterior Cingulate ◽

Hemodynamic Changes ◽

Whole Brain ◽

Brain Hemodynamics

While near-infrared (NIR) spectroscopy has been increasingly used to detect stimulated brain activities with an advantage of dissociating regional oxy- and deoxyhemoglobin concentrations simultaneously, it has not been utilized much in pain research. Here, we investigated and demonstrated the feasibility of using this technique to obtain whole brain hemodynamics in rats and speculated on the functional relevance of the NIR-based hemodynamic signals during pain processing. NIR signals were emitted and collected using a 26-optodes array on rat's dorsal skull surface after the removal of skin. Following the subcutaneous injection of formalin (50 μl, 3%) into a hindpaw, several isolable brain regions showed hemodynamic changes, including the anterior cingulate cortex, primary/secondary somatosensory cortexes, thalamus, and periaqueductal gray ( n = 6). Time courses of hemodynamic changes in respective regions matched with the well-documented biphasic excitatory response. Surprisingly, an atypical pattern (i.e., a decrease in oxyhemoglobin concentration with a concomitant increase in deoxyhemoglobin concentration) was seen in phase II. In a separate group of rats with innocuous brush and noxious pinch of the same area ( n = 11), results confirmed that the atypical pattern occurred more likely in the presence of nociception than nonpainful stimulation, suggesting it as a physiological substrate when the brain processes pain. In conclusion, the NIR whole brain imaging provides a useful alternative to study pain in vivo using small-animal models. Our results support the notion that neurovascular response patterns depend on stimuli, bringing attention to the interpretation of vascular-based neuroimaging data in studies of pain.

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Increased sensitivity to strong perturbations in a whole-brain model of LSD

10.1101/2021.01.05.425415 ◽

2021 ◽

Author(s):

Beatrice M. Jobst ◽

Selen Atasoy ◽

Adrián Ponce-Alvarez ◽

Ana Sanjuán ◽

Leor Roseman ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

External Perturbation ◽

Brain Regions ◽

Lysergic Acid ◽

Functional Magnetic Resonance ◽

Resonance Imaging ◽

Whole Brain ◽

Response Diversity ◽

Brain States ◽

The Brain

AbstractLysergic acid diethylamide (LSD) is a potent psychedelic drug, which has seen a revival in clinical and pharmacological research within recent years. Human neuroimaging studies have shown fundamental changes in brain-wide functional connectivity and an expansion of dynamical brain states, thus raising the question about a mechanistic explanation of the dynamics underlying these alterations. Here, we applied a novel perturbational approach based on a whole-brain computational model, which opens up the possibility to externally perturb different brain regions in silico and investigate differences in dynamical stability of different brain states, i.e. the dynamical response of a certain brain region to an external perturbation. After adjusting the whole-brain model parameters to reflect the dynamics of functional magnetic resonance imaging (fMRI) BOLD signals recorded under the influence of LSD or placebo, perturbations of different brain areas were simulated by either promoting or disrupting synchronization in the regarding brain region. After perturbation offset, we quantified the recovery characteristics of the brain area to its basal dynamical state with the Perturbational Integration Latency Index (PILI) and used this measure to distinguish between the two brain states. We found significant changes in dynamical complexity with consistently higher PILI values after LSD intake on a global level, which indicates a shift of the brain’s global working point further away from a stable equilibrium as compared to normal conditions. On a local level, we found that the largest differences were measured within the limbic network, the visual network and the default mode network. Additionally, we found a higher variability of PILI values across different brain regions after LSD intake, indicating higher response diversity under LSD after an external perturbation. Our results provide important new insights into the brain-wide dynamical changes underlying the psychedelic state - here provoked by LSD intake - and underline possible future clinical applications of psychedelic drugs in particular psychiatric disorders.HighlightsNovel offline perturbational method applied on functional magnetic resonance imaging (fMRI) data under the effect of lysergic acid diethylamide (LSD)Shift of brain’s global working point to more complex dynamics after LSD intakeConsistently longer recovery time after model perturbation under LSD influenceStrongest effects in resting state networks relevant for psychedelic experienceHigher response diversity across brain regions under LSD influence after an external in silico perturbation

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White-matter free-water diffusion MRI in schizophrenia: a systematic review and meta-analysis

Neuropsychopharmacology ◽

10.1038/s41386-022-01272-x ◽

2022 ◽

Author(s):

Inês Carreira Figueiredo ◽

Faith Borgan ◽

Ofer Pasternak ◽

Federico E. Turkheimer ◽

Oliver D. Howes

Keyword(s):

White Matter ◽

Healthy Volunteers ◽

Diffusion Mri ◽

Clinical Symptoms ◽

Free Water ◽

Brain Regions ◽

Water Levels ◽

First Episode ◽

Whole Brain ◽

Illness Duration

AbstractWhite-matter abnormalities, including increases in extracellular free-water, are implicated in the pathophysiology of schizophrenia. Recent advances in diffusion magnetic resonance imaging (MRI) enable free-water levels to be indexed. However, the brain levels in patients with schizophrenia have not yet been systematically investigated. We aimed to meta-analyse white-matter free-water levels in patients with schizophrenia compared to healthy volunteers. We performed a literature search in EMBASE, MEDLINE, and PsycINFO databases. Diffusion MRI studies reporting free-water in patients with schizophrenia compared to healthy controls were included. We investigated the effect of demographic variables, illness duration, chlorpromazine equivalents of antipsychotic medication, type of scanner, and clinical symptoms severity on free-water measures. Ten studies, including five of first episode of psychosis have investigated free-water levels in schizophrenia, with significantly higher levels reported in whole-brain and specific brain regions (including corona radiata, internal capsule, superior and inferior longitudinal fasciculus, cingulum bundle, and corpus callosum). Six studies, including a total of 614 participants met the inclusion criteria for quantitative analysis. Whole-brain free-water levels were significantly higher in patients relative to healthy volunteers (Hedge’s g = 0.38, 95% confidence interval (CI) 0.07–0.69, p = 0.02). Sex moderated this effect, such that smaller effects were seen in samples with more females (z = −2.54, p < 0.05), but antipsychotic dose, illness duration and symptom severity did not. Patients with schizophrenia have increased free-water compared to healthy volunteers. Future studies are necessary to determine the pathological sources of increased free-water, and its relationship with illness duration and severity.

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Brain-wide mapping of water flow perception in zebrafish

10.1101/2020.01.07.896738 ◽

2020 ◽

Cited By ~ 1

Author(s):

Gilles Vanwalleghem ◽

Kevin Schuster ◽

Michael A. Taylor ◽

Itia A. Favre-Bulle ◽

Ethan K. Scott

Keyword(s):

Water Flow ◽

Lateral Line ◽

Reverse Flow ◽

Forward Direction ◽

Brain Regions ◽

Reverse Direction ◽

Departure Point ◽

Forward Flow ◽

Larval Zebrafish ◽

The Brain

AbstractInformation about water flow, detected by lateral line organs, is critical to the behavior and survival of fish and amphibians. While certain specific aspects of water flow processing have been revealed through electrophysiology, we lack a comprehensive description of the neurons that respond to water flow and the network that they form. Here, we use brain-wide calcium imaging in combination with microfluidic stimulation to map out, at cellular resolution, all neurons involved in perceiving and processing water flow information in larval zebrafish. We find a diverse array of neurons responding to forward flow, reverse flow, or both. Early in this pathway, in the lateral line ganglia, these are almost exclusively neurons responding to the simple presence of forward or reverse flow, but later processing includes neurons responding specifically to flow onset, representing the accumulated volume of flow during a stimulus, or encoding the speed of the flow. The neurons reporting on these more nuanced details are located across numerous brain regions, including some not previously implicated in water flow processing. A graph theory-based analysis of the brain-wide water flow network shows that a majority of this processing is dedicated to forward flow detection, and this is reinforced by our finding that details like flow velocity and the total volume of accumulated flow are only encoded for the simulated forward direction. The results represent the first brain-wide description of processing for this important modality, and provide a departure point for more detailed studies of the flow of information through this network.Significance statementIn aquatic animals, the lateral line is important for detecting water flow stimuli, but the brain networks that interpret this information remain mysterious. Here, we have imaged the activity of individual neurons across the entire brains of larval zebrafish, revealing all response types and their brain locations as water flow processing occurs. We find some neurons that respond to the simple presence of water flow, and others that are attuned to the flow’s direction, speed, duration, or the accumulated volume of water that has passed during the stimulus. With this information, we modeled the underlying network, describing a system that is nuanced in its processing of water flow simulating forward motion but rudimentary in processing flow in the reverse direction.

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Neural selectivity for visual motion in macaque area V3A

10.1101/2020.09.15.298349 ◽

2020 ◽

Author(s):

Nardin Nakhla ◽

Yavar Korkian ◽

Matthew R. Krause ◽

Christopher C. Pack

Keyword(s):

Visual Cortex ◽

Optic Flow ◽

Functional Role ◽

Visual Motion ◽

Flow Patterns ◽

Brain Regions ◽

Direction Selectivity ◽

Motion Processing ◽

Imaging Studies ◽

Motion Direction

AbstractThe processing of visual motion is carried out by dedicated pathways in the primate brain. These pathways originate with populations of direction-selective neurons in the primary visual cortex, which project to dorsal structures like the middle temporal (MT) and medial superior temporal (MST) areas. Anatomical and imaging studies have suggested that area V3A might also be specialized for motion processing, but there have been very few studies of single-neuron direction selectivity in this area. We have therefore performed electrophysiological recordings from V3A neurons in two macaque monkeys (one male and one female) and measured responses to a large battery of motion stimuli that includes translation motion, as well as more complex optic flow patterns. For comparison, we simultaneously recorded the responses of MT neurons to the same stimuli. Surprisingly, we find that overall levels of direction selectivity are similar in V3A and MT and moreover that the population of V3A neurons exhibits somewhat greater selectivity for optic flow patterns. These results suggest that V3A should be considered as part of the motion processing machinery of the visual cortex, in both human and non-human primates.Significance statementAlthough area V3A is frequently the target of anatomy and imaging studies, little is known about its functional role in processing visual stimuli. Its contribution to motion processing has been particularly unclear, with different studies yielding different conclusions. We report a detailed study of direction selectivity in V3A. Our results show that single V3A neurons are, on average, as capable of representing motion direction as are neurons in well-known structures like MT. Moreover, we identify a possible specialization for V3A neurons in representing complex optic flow, which has previously been thought to emerge in higher-order brain regions. Thus it appears that V3A is well-suited to a functional role in motion processing.

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