scholarly journals Whole-head recording of chemosensory activity in the marine annelid Platynereis dumerilii

Open Biology ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 180139 ◽  
Author(s):  
Thomas F. Chartier ◽  
Joran Deschamps ◽  
Wiebke Dürichen ◽  
Gáspár Jékely ◽  
Detlev Arendt
Keyword(s):  
Sensory Modality ◽  
Marine Species ◽  
Brain Regions ◽  
Comparative Approach ◽  
Platynereis Dumerilii ◽  
Evoked Activity ◽  
Nuchal Organs ◽  
Chemosensory Systems ◽  
Chemosensory Organs ◽  
Behavioural Repertoire

Chemical detection is key to various behaviours in both marine and terrestrial animals. Marine species, though highly diverse, have been underrepresented so far in studies on chemosensory systems, and our knowledge mostly concerns the detection of airborne cues. A broader comparative approach is therefore desirable. Marine annelid worms with their rich behavioural repertoire represent attractive models for chemosensation. Here, we study the marine worm Platynereis dumerilii to provide the first comprehensive investigation of head chemosensory organ physiology in an annelid. By combining microfluidics and calcium imaging, we record neuronal activity in the entire head of early juveniles upon chemical stimulation. We find that Platynereis uses four types of organs to detect stimuli such as alcohols, esters, amino acids and sugars. Antennae are the main chemosensory organs, compared to the more differentially responding nuchal organs or palps. We report chemically evoked activity in possible downstream brain regions including the mushroom bodies (MBs), which are anatomically and molecularly similar to insect MBs. We conclude that chemosensation is a major sensory modality for marine annelids and propose early Platynereis juveniles as a model to study annelid chemosensory systems.

scholarly journals Whole-head recording of chemosensory activity in the marine annelidPlatynereis dumerilii

2018 ◽  
Author(s):  
Thomas F. Chartier ◽  
Joran Deschamps ◽  
Wiebke Duerichen ◽  
Gaspar Jekely ◽  
Detlev Arendt
Keyword(s):  
Sensory Modality ◽  
Marine Species ◽  
Brain Regions ◽  
Comparative Approach ◽  
Mushroom Bodies ◽  
Evoked Activity ◽  
Nuchal Organs ◽  
Chemosensory Systems ◽  
Chemosensory Organs ◽  
Behavioural Repertoire

Chemical detection is key to various behaviours in both marine and terrestrial animals. Marine species, though highly diverse, have been underrepresented so far in studies on chemosensory systems, and our knowledge mostly concerns the detection of airborne cues. A broader comparative approach is therefore desirable. Marine annelid worms with their rich behavioural repertoire represent attractive models for chemosensory studies. Here, we study the marine wormPlatynereis dumeriliito provide the first comprehensive study of head chemosensory organ physiology in an annelid. By combining microfluidics and calcium imaging, we record neuronal activity in the entire head of early juveniles upon chemical stimulation. We find thatPlatynereisuses four types of organs to detect stimuli such as alcohols, esters, amino acids and sugars. Antennae, but not nuchal organs or palps as generally hypothesised in annelids, are the main chemosensory organs. We report chemically-evoked activity in possible downstream brain regions including the mushroom bodies, which are anatomically and molecularly similar to insect mushroom bodies. We conclude that chemosensation is a major sensory modality for marine annelids, and propose earlyPlatynereisjuveniles as a model to study annelid chemosensory systems.

scholarly journals Brain networks underlying the processing of sound symbolism related to softness perception

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryo Kitada ◽  
Jinhwan Kwon ◽  
Ryuichi Doizaki ◽  
Eri Nakagawa ◽  
Tsubasa Tanigawa ◽  
...  
Keyword(s):  
Inferior Frontal Gyrus ◽  
Sensory Modality ◽  
Brain Regions ◽  
Sound Symbolism ◽  
Matching Task ◽  
Unique Contribution ◽  
Superior Frontal Gyrus ◽  
Symbolic Information ◽  
Object Properties ◽  
Imaging Experiment

AbstractUnlike the assumption of modern linguistics, there is non-arbitrary association between sound and meaning in sound symbolic words. Neuroimaging studies have suggested the unique contribution of the superior temporal sulcus to the processing of sound symbolism. However, because these findings are limited to the mapping between sound symbolism and visually presented objects, the processing of sound symbolic information may also involve the sensory-modality dependent mechanisms. Here, we conducted a functional magnetic resonance imaging experiment to test whether the brain regions engaged in the tactile processing of object properties are also involved in mapping sound symbolic information with tactually perceived object properties. Thirty-two healthy subjects conducted a matching task in which they judged the congruency between softness perceived by touch and softness associated with sound symbolic words. Congruency effect was observed in the orbitofrontal cortex, inferior frontal gyrus, insula, medial superior frontal gyrus, cingulate gyrus, and cerebellum. This effect in the insula and medial superior frontal gyri was overlapped with softness-related activity that was separately measured in the same subjects in the tactile experiment. These results indicate that the insula and medial superior frontal gyrus play a role in processing sound symbolic information and relating it to the tactile softness information.

scholarly journals Functional integration of “undead” neurons in the olfactory system

2019 ◽  
Author(s):  
Lucia L. Prieto-Godino ◽  
Ana F. Silbering ◽  
Mohammed A. Khallaf ◽  
Steeve Cruchet ◽  
Karolina Bojkowska ◽  
...  
Keyword(s):  
Olfactory System ◽  
Functional Integration ◽  
Olfactory Receptors ◽  
Neural Pathways ◽  
Life Stages ◽  
Evoked Activity ◽  
Functional Neuron ◽  
Circuit Formation ◽  
The Brain ◽  
Chemosensory Organs

ABSTRACTProgrammed cell death (PCD) is widespread during neurodevelopment, typically eliminating the surpluses of neuronal production. Employing the Drosophila olfactory system, we examined the potential of cells fated to die to contribute to circuit evolution. Inhibition of PCD is sufficient to generate many new cells that express neural markers and exhibit odor-evoked activity. These “undead” neurons express a subset of olfactory receptors that, intriguingly, is enriched for recent receptor duplicates and include some normally found in other chemosensory organs and life-stages. Moreover, undead neuron axons integrate into the olfactory circuitry in the brain, forming novel receptor/glomerular couplings. Comparison of homologous olfactory lineages across drosophilids reveals natural examples of fate changes from death to a functional neuron. Finally, we provide evidence that PCD contributes to evolutionary differences in carbon dioxide-sensing circuit formation in Drosophila and mosquitoes. These results reveal the remarkable potential of alterations in PCD patterning to evolve new neural pathways.

scholarly journals Multi-sensory integration in the mouse cortical connectome using a network diffusion model

2019 ◽  
Author(s):  
Kamal Shadi ◽  
Eva Dyer ◽  
Constantine Dovrolis
Keyword(s):  
Diffusion Model ◽  
Temporal Cortex ◽  
Sensory Information ◽  
Brain Regions ◽  
Evoked Activity ◽  
Communication Dynamics ◽  
Activation Cascade ◽  
Alt Model ◽  
The Brain ◽  
Network Diffusion

AbstractHaving a structural network representation of connectivity in the brain is instrumental in analyzing communication dynamics and information processing in the brain. In this work, we make steps towards understanding multi-sensory information flow and integration using a network diffusion approach. In particular, we model the flow of evoked activity, initiated by stimuli at primary sensory regions, using the Asynchronous Linear Threshold (ALT) diffusion model. The ALT model captures how evoked activity that originates at a given region of the cortex “ripples through” other brain regions (referred to as an activation cascade). By comparing the model results to functional datasets based on Voltage Sensitive Dye (VSD) imaging, we find that in most cases the ALT model predicts the temporal ordering of an activation cascade correctly. Our results on the Mouse Connectivity Atlas from the Allen Institute for Brain Science show that a small number of brain regions are involved in many primary sensory streams – the claustrum and the parietal temporal cortex being at the top of the list. This suggests that the cortex relies on an hourglass architecture to first integrate and compress multi-sensory information from multiple sensory regions, before utilizing that lower-dimensionality representation in higher-level association regions and more complex cognitive tasks.

scholarly journals Two spatially distinct posterior alpha sources fulfill different functional roles in attention

2018 ◽  
Author(s):  
R. Sokoliuk ◽  
S.D. Mayhew ◽  
K.M. Aquino ◽  
R. Wilson ◽  
M.J. Brookes ◽  
...  
Keyword(s):  
Sensory Modality ◽  
Somatosensory System ◽  
Spatial Location ◽  
Relevant Information ◽  
Brain Regions ◽  
Alpha Power ◽  
Functional Roles ◽  
Attention Tasks ◽  
Eeg Data ◽  
Visual Hemifields

ABSTRACTDirecting attention helps to extract relevant information and suppress distracters. Alpha brain oscillations (8-12Hz) play a fundamental role in this process, with a power decrease facilitating processing of important information and power increase inhibiting brain regions processing irrelevant information. Evidence for this phenomenon arises from visual attention studies (Worden et al., 2000), however, the effect also exists in other modalities, including the somatosensory system (Haegens et al., 2011) and inter-sensory attention tasks (Foxe and Snyder, 2011). We investigated what happens when attention is divided between two modalities using both a multi- and unimodal attention paradigm while recording EEG over 128 scalp electrodes in two separate experiments. In Experiment 1 participants divided their attention between the visual and somatosensory modality to determine the temporal or spatial frequency of a target stimulus (vibrotactile stimulus or Gabor grating). In Experiment 2, participants divided attention between two visual hemifields to identify the orientation of a target Gabor grating. In both experiments, pre-stimulus alpha power in visual areas decreased linearly with increasing attention to visual stimuli. In contrast, alpha power in parietal areas showed lower pre-stimulus alpha power when attention was divided between modalities, compared to unimodal attention. These results suggest that there are two different alpha sources, where one reflects the ‘visual spotlight of attention’ and the other reflects attentional effort. To our knowledge, this is the first study to show that attention recruits two spatially distinct alpha sources in occipital and parietal brain regions, which act simultaneously but serve different functions in attention.SIGNIFICANCE STATEMENTAttention to one spatial location/sensory modality leads to power changes of alpha oscillations (~10Hz) with decreased power over regions processing relevant information and power increases to actively inhibit areas processing ‘to-be-ignored’ information. Here, we used detailed source modelling to investigate EEG data recorded during separate uni-modal (visual) and multi- (visual and somatosensory) attention tasks. Participants either focused their attention on one modality/spatial location or directed it to both. We show for the first time two distinct alpha sources are active simultaneously but play different roles. A sensory (visual) alpha source was linearly modulated by attention representing the ‘visual spotlight of attention’. In contrast, a parietal alpha source was modulated by attentional effort, showing lowest alpha power when attention was divided.

scholarly journals Activity flow underlying abnormalities in brain activations and cognition in schizophrenia

2021 ◽  
Vol 7 (29) ◽  
pp. eabf2513
Author(s):  
Luke J. Hearne ◽  
Ravi D. Mill ◽  
Brian P. Keane ◽  
Grega Repovš ◽  
Alan Anticevic ◽  
...  
Keyword(s):  
Cognitive Dysfunction ◽  
Large Scale ◽  
Brain Activity ◽  
Memory Task ◽  
Clinical Intervention ◽  
Brain Regions ◽  
Imaging Data ◽  
Flow Mapping ◽  
Flow Models ◽  
Evoked Activity

Cognitive dysfunction is a core feature of many brain disorders, including schizophrenia (SZ), and has been linked to aberrant brain activations. However, it is unclear how these activation abnormalities emerge. We propose that aberrant flow of brain activity across functional connectivity (FC) pathways leads to altered activations that produce cognitive dysfunction in SZ. We tested this hypothesis using activity flow mapping, an approach that models the movement of task-related activity between brain regions as a function of FC. Using functional magnetic resonance imaging data from SZ individuals and healthy controls during a working memory task, we found that activity flow models accurately predict aberrant cognitive activations across multiple brain networks. Within the same framework, we simulated a connectivity-based clinical intervention, predicting specific treatments that normalized brain activations and behavior in patients. Our results suggest that dysfunctional task-evoked activity flow is a large-scale network mechanism contributing to cognitive dysfunction in SZ.

Section 1 Summary—Evolutionary Origins and Transitions in Developmental Mode

2018 ◽  
Keyword(s):  
Life Histories ◽  
Marine Invertebrates ◽  
Morphological Characteristics ◽  
Biotic Interactions ◽  
Reproductive Mode ◽  
Marine Species ◽  
Comparative Approach ◽  
Closely Related Species ◽  
Larval Stages ◽  
Evolutionary Origins

Abiotic variables and biotic interactions can act on variation in life history traits, ultimately leading to divergence in reproductive mode. Marine invertebrates have a remarkable diversity in such strategies, sometimes even between closely related species. It is this natural diversity that lends itself to employing a powerful comparative approach, both for particular morphological characteristics as well as molecular signatures from developmental genes. For example, complex life histories, where a larval stage is interposed between the embryo and juvenile, likely represent the product of numerous selection pressures, historical and current, that have shaped the diversity of larval stages in extant marine species. In fact, the very question about “what is a larva?” has to be addressed, as it is so intimately connected to bentho-planktonic life cycle and metamorphosis. Furthermore, novel larval types have evolved in particular lineages and larvae have been secondarily lost in others. This in itself creates an interesting and exciting playground to test evolutionary developmental hypotheses....

The mechanism and neural substrate of musical emotions in the audio-visual modality

2021 ◽  
pp. 030573562110420
Author(s):  
Xin Zhou ◽  
Ying Wu ◽  
Yingcan Zheng ◽  
Zilun Xiao ◽  
Maoping Zheng
Keyword(s):  
Musical Training ◽  
Block Design ◽  
Sensory Modality ◽  
Neural Mechanism ◽  
Brain Regions ◽  
Visual Modality ◽  
Training Experience ◽  
Musical Expertise ◽  
Fmri Study ◽  
Bilateral Distribution

Previous studies on multisensory integration (MSI) of musical emotions have yielded inconsistent results. The distinct features of the music materials and different musical expertise levels of participants may account for that. This study aims to explore the neural mechanism for the audio-visual integration of musical emotions and infer the reasons for inconsistent results in previous studies by investigating the influence of the type of musical emotions and musical training experience on the mechanism. This fMRI study used a block-design experiment. Music excerpts were selected to express fear, happiness, and sadness, presented under audio only (AO) and audio-visual (AV) modality conditions. Participants were divided into two groups: one comprising musicians who had been musically trained for many years and the other non-musicians with no musical expertise. They assessed the type and intensity of musical emotion after listening to or watching excerpts. Brain regions related to MSI of emotional information and default mode network (DMN) are sensitive to sensory modality conditions and emotion-type changes. Participants in the non-musician group had more, and bilateral distribution of brain regions showed greater activation in the AV assessment stage. By contrast, the musician group had less and lateralized right-hemispheric distribution of brain regions.

scholarly journals Reading Salt Activates Gustatory Brain Regions: fMRI Evidence for Semantic Grounding in a Novel Sensory Modality

2011 ◽  
Vol 22 (11) ◽  
pp. 2554-2563 ◽  
Author(s):  
Alfonso Barrós-Loscertales ◽  
Julio González ◽  
Friedemann Pulvermüller ◽  
Noelia Ventura-Campos ◽  
Juan Carlos Bustamante ◽  
...  
Keyword(s):  
Sensory Modality ◽  
Brain Regions

Responses to Rare Visual Target and Distractor Stimuli Using Event-Related fMRI

2000 ◽  
Vol 83 (5) ◽  
pp. 3133-3139 ◽  
Author(s):  
Vincent P. Clark ◽  
Sean Fannon ◽  
Song Lai ◽  
Randall Benson ◽  
Lance Bauer
Keyword(s):  
Brain Activity ◽  
Temporal Cortex ◽  
Stimulus Presentation ◽  
Brain Regions ◽  
Event Related Potential ◽  
Anterior Cingulate ◽  
Fmri Signal ◽  
Fmri Study ◽  
Evoked Activity ◽  
Anatomic Locations

Previous studies have found that the P300 or P3 event-related potential (ERP) component is useful in the diagnosis and treatment of many disorders that influence CNS function. However, the anatomic locations of brain regions involved in this response are not precisely known. In the present event-related functional magnetic resonance imaging (fMRI) study, methods of stimulus presentation, data acquisition, and data analysis were optimized for the detection of brain activity in response to stimuli presented in the three-stimulus oddball task. This paradigm involves the interleaved, pseudorandom presentation of single block-letter target and distractor stimuli that previously were found to generate the P3b and P3a ERP subcomponents, respectively, and frequent standard stimuli. Target stimuli evoked fMRI signal increases in multiple brain regions including the thalamus, the bilateral cerebellum, and the occipital-temporal cortex as well as bilateral superior, medial, inferior frontal, inferior parietal, superior temporal, precentral, postcentral, cingulate, insular, left middle temporal, and right middle frontal gyri. Distractor stimuli evoked an fMRI signal change bilaterally in inferior anterior cingulate, medial frontal, inferior frontal, and right superior frontal gyri, with additional activity in bilateral inferior parietal lobules, lateral cerebellar hemispheres and vermis, and left fusiform, middle occipital, and superior temporal gyri. Significant variation in the amplitude and polarity of distractor-evoked activity was observed across stimulus repetitions. No overlap was observed between target- and distractor-evoked activity. These event-related fMRI results shed light on the anatomy of responses to target and distractor stimuli that have proven useful in many ERP studies of healthy and clinically impaired populations.

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