Search

Your search keyword '"Ben Hamed S"' showing total 153 results
Start Over Author "Ben Hamed S"
153 results on '"Ben Hamed S"'

5. Toward next-generation primate neuroscience: a collaboration-based strategic plan for integrative neuroimaging

Author

Milham, M.P., Petkov, C.I., Belin, P., Ben Hamed, S., Evrard, H.C., Fair, D.A., Mars, R.B., Zhao, Y., Zuo, Z., Milham, M.P., Petkov, C.I., Belin, P., Ben Hamed, S., Evrard, H.C., Fair, D.A., Mars, R.B., Zhao, Y., and Zuo, Z.

Abstract

Item does not contain fulltext, Open science initiatives are creating opportunities to increase research coordination and impact in nonhuman primate (NHP) imaging. The PRIMatE Data and Resource Exchange community recently developed a collaboration-based strategic plan to advance NHP imaging as an integrative approach for multiscale neuroscience.

Published
2022

8. Neural correlates of audio-visual integration of socially meaningful information in macaque monkeys

Author

Marc Hauser, Ben Hamed S, Mathilda Froesel, Maëva Gacoin, Clavagnier S, and Quentin Goudard

Subjects
Dorsolateral prefrontal cortex, Facial expression, medicine.anatomical_structure, Stimulus modality, medicine, Lateral sulcus, Orbitofrontal cortex, Intraparietal sulcus, Superior temporal sulcus, Psychology, Insular cortex, Neuroscience
Abstract

Social interactions rely on the ability to interpret semantic and emotional information, often from multiple sensory modalities. In human and nonhuman primates, both the auditory and visual modalities are used to generate and interpret communicative signals. In individuals with autism, not only are there deficits in social communication, but in the integration of audio-visual information. At present, we know little about the neural mechanisms that subserve the interpretation of complex social events, including the audio-visual integration that is often required with accompanying communicative signals. Based on heart rate estimates and fMRI in two macaque monkeys (Macaca mulatta), we show that individuals systematically associate affiliative facial expressions or social scenes with corresponding affiliative vocalizations, aggressive facial expressions or social scenes with corresponding aggressive vocalizations and escape visual scenes with scream vocalizations. In contrast, vocalizations that are incompatible with the visual information are fully suppressed, suggesting top-down regulation over the processing of sensory input. The process of binding audio-visual semantic and contextual information relies on a core functional network involving the superior temporal sulcus (STS) and lateral sulcus (LS). Peak activations in both sulci co-localize with face or voice patches that have been previously described. While all of these regions of interest (ROIs) respond to both auditory and visual information, LS ROIs have a preference for auditory and audio-visual congruent stimuli while STS ROIs equally respond to auditory, visual and audio-visual congruent stimuli. To further specify the cortical network involved in the control of this semantic association, we performed a whole brain gPPI functional connectivity analysis on the LS and STS cumulated ROIs. This gPPI analysis highlights a functional network connected to the LS and STS, involving the anterior cingulate cortex (ACC), area 46 in the dorsolateral prefrontal cortex (DLPFC), the orbitofrontal cortex (OFC), the intraparietal sulcus (IPS), the insular cortex and subcortically, the amygdala and the hippocampus. Comparing human and macaque results, we propose that the integration of audio-visual information for congruent, meaningful social events involves homologous neural circuitry, specifically, an emotional network composed of the STS, LS, ACC, OFC, and limbic areas, including the amygdala, and an attentional network including the STS, LS, IPS and DLPFC. As such, these networks are critical to the amodal representation of social meaning, thereby providing an explanation for some of deficits observed in autism.

Published
2021

9. Selection and suppression of visual information in the macaque prefrontal cortex

Author

Di Bello, F., Ben Hadj Hassen, S., Astrand, E., Ben Hamed, S., Institut des sciences cognitives Marc Jeannerod - Centre de neuroscience cognitive - UMR5229 (CNC), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)

Subjects
proactive suppression, Process (engineering), Computer science, media_common.quotation_subject, distractor suppression, Sensory system, Macaque, 050105 experimental psychology, 03 medical and health sciences, 0302 clinical medicine, reactive suppression, Perception, Distraction, biology.animal, 0501 psychology and cognitive sciences, Prefrontal cortex, Selection (genetic algorithm), media_common, prefrontal cortex, biology, priority map, attention selection, [SCCO.NEUR]Cognitive science/Neuroscience, 05 social sciences, attention, attentional spotlight, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], Neuroscience, 030217 neurology & neurosurgery
Abstract

In everyday life, we are continuously struggling at focusing on our current goals while at the same time avoiding distractions. Attention is the neuro-cognitive process devoted to the selection of behaviorally relevant sensory information while at the same time preventing distraction by irrelevant information. Visual selection can be implemented by both long-term (learning-based spatial prioritization) and short term (dynamic spatial attention) mechanisms. On the other hand, distraction can be prevented proactively, by strategically prioritizing task-relevant information at the expense of irrelevant information, or reactively, by actively suppressing the processing of distractors. The distinctive neuronal signature of each of these four processes is largely unknown. Likewise, how selection and suppression mechanisms interact to drive perception has never been explored neither at the behavioral nor at the neuronal level. Here, we apply machine-learning decoding methods to prefrontal cortical (PFC) activity to monitor dynamic spatial attention with an unprecedented spatial and temporal resolution. This leads to several novel observations. We first identify independent behavioral and neuronal signatures for learning-based attention prioritization and dynamic attentional selection. Second, we identify distinct behavioral and neuronal signatures for proactive and reactive suppression mechanisms. We find that while distracting task-relevant information is suppressed proactively, task-irrelevant information is suppressed reactively. Critically, we show that distractor suppression, whether proactive or reactive, strongly depends on both learning-based attention prioritization and dynamic attentional selection. Overall, we thus provide a unified neuro-cognitive framework describing how the prefrontal cortex implements spatial selection and distractor suppression in order to flexibly optimize behavior in dynamic environments.

Published
2020

10. Neuronal population correlates of target selection and distractor filtering

Author

Åstrand, Elaine, Wardak, C., Ben Hamed, S., Åstrand, Elaine, Wardak, C., and Ben Hamed, S.

Abstract

Frontal Eye Field (FEF) neurons discriminate between relevant and irrelevant visual stimuli and their response magnitude predicts conscious perception. How this is reflected in the spatial representation of a visual stimulus at the neuronal population level is unknown. We recorded neuronal population activity in the FEF while monkeys were performing a forced choice cued detection task with identical target and distractor stimuli. We quantified, using machine learning techniques, estimates of target and distractor location from FEF population multiunit activities. We found that the FEF population activity provides a precise single trial estimate of reported stimuli locations. Importantly, the closer this prefrontal population single trial estimate is to the veridical stimulus location, the higher the probability that the target or the distractor is reported as perceived. We show that stimulus perception is rescued by the estimate of attention allocation specifically when the latter is close enough to the actual stimulus location, thus indicating a partial independence between attention and perception. Overall, we thus show that how and what we perceive of our environment depends on the spatial precision with which this environment is coded by prefrontal neuronal populations.

Published
2020
Full Text
View/download PDF

16. Interneuronal correlations dynamically adjust to task demands at multiple time-scales

Author

Elaine Astrand, Ben Hamed S, Claire Wardak, Ben Hadj Hassen S, Corentin Gaillard, Institut des sciences cognitives Marc Jeannerod - Centre de neuroscience cognitive - UMR5229 (CNC), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)

Subjects
cognitive demand, Computer science, media_common.quotation_subject, Summary, alpha oscillations, cognitive flexibility, 03 medical and health sciences, 0302 clinical medicine, Perception, Premovement neuronal activity, Prefrontal cortex, 030304 developmental biology, media_common, prefrontal cortex, beta oscillations, 0303 health sciences, [SCCO.NEUR]Cognitive science/Neuroscience, Cognitive flexibility, Information processing, task difficulty, Cognition, Cortical neurons, Frontal eye fields, macaque monkey, Noise, Neuronal noise, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], noise correlation, rhythmic cognition, Neuroscience, 030217 neurology & neurosurgery
Abstract

Summary Functional neuronal correlations between pairs of neurons are thought to play an important role in neuronal information processing and optimal neuronal computations during attention, perception, decision-making and learning. Here, we report dynamic changes in prefrontal neuronal noise correlations at multiple time-scales, as a function of task contingencies. Specifically, we record neuronal activity from the macaque frontal eye fields, a cortical region at the source of spatial attention top-down control, while the animals are engaged in tasks of varying cognitive demands. We show that the higher the task demand and cognitive engagement the lower noise correlations. We further report that within a given task, noise correlations significantly decrease in epoch of higher response probability. Last we show that the power of the rhythmic modulations of noise correlations in the alpha and beta frequency ranges also decreases in the most demanding tasks. All of these changes in noise correlations are associated with layer specific modulations in spikes-LFP phase coupling, suggesting both a long-range and a local intra-areal origin. Over all, this indicates a highly dynamic adjustment of noise correlations to ongoing task requirements and suggests a strong functional role of noise correlations in cognitive flexibility. Significance statement Cortical neurons are densely interconnected. As a result, pairs of neurons share some degree of variability in their neuronal responses. This impacts how much information is present within a neuronal population and is critical to attention, decision-making and learning. Here we show that, in the prefrontal cortex, this shared inter-neuronal variability is highly flexible, decreasing across tasks as cognitive demands increase and within trials in epochs of maximal behavioral demand. It also fluctuates in time at a specific rhythm, the power of which decreases for higher cognitive demand. All of these changes in noise correlations are associated with layer specific modulations in spikes-LFP phase coupling. Over all, this suggests a strong functional role of noise correlations in cognitive flexibility.

Published
2019
Full Text
View/download PDF

20. An open resource for non-human primate imaging

Author

Milham, M.P., Ai, L., Koo, B., Xu, T., Amiez, C., Balezeau, F., Baxter, M.G., Blezer, E.L.A., Brochier, T., Chen, A., Croxson, P.L., Damatac, C.G., Dehaene, S., Everling, S., Fair, D.A., Fleysher, L., Freiwald, W., Froudist-Walsh, S., Griffiths, T.D., Guedj, C., Hadj-Bouziane, F., Ben Hamed, S., Harel, N., Hiba, B., Jarraya, B., Jung, B., Kastner, S., Klink, P.C., Kwok, S.C., Laland, K.N., Leopold, D.A., Lindenfors, P., Mars, R.B., Menon, R.S., Messinger, A., Meunier, M., Mok, K., Morrison, J.H., Nacef, J., Nagy, J., Rios, M.O., Petkov, C.I., Pinsk, M.A., Poirier, C., Procyk, E., Rajimehr, R., Reader, S.M., Roelfsema, P.R., Rudko, D.A., Rushworth, M.F.S., Russ, B.E., Sallet, J., Schmid, M.C., Schwiedrzik, C.M., Seidlitz, J., Sein, J., Shmuel, A., Sullivan, E.L., Ungerleider, L., Thiele, A., Todorov, O.S., Tsao, D., Wang, Z., Wilson, C.R.E., Yacoub, E., Ye, F.Q., Zarco, W., Zhou, Y.D., Margulies, D.S., Schroeder, C.E., Milham, M.P., Ai, L., Koo, B., Xu, T., Amiez, C., Balezeau, F., Baxter, M.G., Blezer, E.L.A., Brochier, T., Chen, A., Croxson, P.L., Damatac, C.G., Dehaene, S., Everling, S., Fair, D.A., Fleysher, L., Freiwald, W., Froudist-Walsh, S., Griffiths, T.D., Guedj, C., Hadj-Bouziane, F., Ben Hamed, S., Harel, N., Hiba, B., Jarraya, B., Jung, B., Kastner, S., Klink, P.C., Kwok, S.C., Laland, K.N., Leopold, D.A., Lindenfors, P., Mars, R.B., Menon, R.S., Messinger, A., Meunier, M., Mok, K., Morrison, J.H., Nacef, J., Nagy, J., Rios, M.O., Petkov, C.I., Pinsk, M.A., Poirier, C., Procyk, E., Rajimehr, R., Reader, S.M., Roelfsema, P.R., Rudko, D.A., Rushworth, M.F.S., Russ, B.E., Sallet, J., Schmid, M.C., Schwiedrzik, C.M., Seidlitz, J., Sein, J., Shmuel, A., Sullivan, E.L., Ungerleider, L., Thiele, A., Todorov, O.S., Tsao, D., Wang, Z., Wilson, C.R.E., Yacoub, E., Ye, F.Q., Zarco, W., Zhou, Y.D., Margulies, D.S., and Schroeder, C.E.

Abstract

Contains fulltext : 196820.pdf (publisher's version ) (Open Access), Non-human primate neuroimaging is a rapidly growing area of research that promises to transform and scale translational and cross-species comparative neuroscience. Unfortunately, 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 25 independent data collections aggregated across 22 sites (total = 217 non-human primates). We also outline the unique pitfalls and challenges that should be considered in the analysis of non-human primate MRI datasets, including providing automated quality assessment of the contributed datasets.

Published
2018

22. Evidence for Enhanced Multisensory Facilitation with Stimulus Relevance: An Electrophysiological Investigation

Author

Ben Hamed, S, Barutchu, A, Freestone, DR, Innes-Brown, H, Crewther, DP, Crewther, SG, Ben Hamed, S, Barutchu, A, Freestone, DR, Innes-Brown, H, Crewther, DP, and Crewther, SG

Abstract

Currently debate exists relating to the interplay between multisensory processes and bottom-up and top-down influences. However, few studies have looked at neural responses to newly paired audiovisual stimuli that differ in their prescribed relevance. For such newly associated audiovisual stimuli, optimal facilitation of motor actions was observed only when both components of the audiovisual stimuli were targets. Relevant auditory stimuli were found to significantly increase the amplitudes of the event-related potentials at the occipital pole during the first 100 ms post-stimulus onset, though this early integration was not predictive of multisensory facilitation. Activity related to multisensory behavioral facilitation was observed approximately 166 ms post-stimulus, at left central and occipital sites. Furthermore, optimal multisensory facilitation was found to be associated with a latency shift of induced oscillations in the beta range (14-30 Hz) at right hemisphere parietal scalp regions. These findings demonstrate the importance of stimulus relevance to multisensory processing by providing the first evidence that the neural processes underlying multisensory integration are modulated by the relevance of the stimuli being combined. We also provide evidence that such facilitation may be mediated by changes in neural synchronization in occipital and centro-parietal neural populations at early and late stages of neural processing that coincided with stimulus selection, and the preparation and initiation of motor action.

Published
2013

35. Action éducative et confusion de langage: des représentations nécessaires chez les parents pour que le travail socioéducatif prenne sens 2 [2] Ce travail reprend et complète ...

Author

Ben Hamed, S.

Subjects
PARENT-child relationships, FAMILIES, INTERPERSONAL relations, ADULT-child relationships
Abstract

Copyright of Pratiques Psychologiques is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2007
Full Text
View/download PDF

38. Attentional brain rhythms during prolonged cognitive activity

Author

Julian L. Amengual, Ben Hadj Hassen S, Ben Hamed S, Ziane C, De Sousa C, Corentin Gaillard, Loriette C, and Di Bello F

Subjects
0303 health sciences, Elementary cognitive task, media_common.quotation_subject, Cognition, Neurophysiology, Arousal, 03 medical and health sciences, 0302 clinical medicine, Rhythm, Orientation (mental), Perception, Psychology, Prefrontal cortex, Neuroscience, 030217 neurology & neurosurgery, 030304 developmental biology, media_common
Abstract

As routine and lower demand cognitive tasks are taken over by automated assistive systems, human operators are increasingly required to sustain cognitive demand over long periods of time. This has been reported to have long term adverse effects on cardiovascular and mental health. However, it remains unclear whether prolonged cognitive activity results in a monotonic decrease in the efficiency of the recruited brain processes, or whether the brain is able to sustain functions over time spans of one hour and more. Here, we show that during working sessions of one hour or more, contrary to the prediction of a monotonic decline, behavioral performance in both humans and non-human primates consistently fluctuates between periods of optimal and suboptimal performance at a very slow rhythm ofcirca5 cycles per hour. These fluctuations are observed in both high attentional (in non-human primates) and low attentional (in humans) demand conditions. They coincide with fluctuations in pupil diameter, indicating underlying changes in arousal and information-processing load. Accordingly, we show that these rhythmic behavioral fluctuations correlate, at the neurophysiological level, with fluctuations in the informational attention orientation and perception processing capacity of prefrontal neuronal populations. We further identify specific markers of these fluctuations in LFP power, LFP coherence and spike-field coherence, pointing towards long-range rhythmic modulatory inputs to the prefrontal cortex rather than a local prefrontal origin. These results shed light on the resilience of brain mechanisms to sustained effort and have direct implications on how to optimize high cognitive demand working and learning environments.

Full Text
View/download PDF

41. Méningite à Streptococcus oralisaprès myélographie

Author

Kanoun, F., Ben Jemaa, M., Mahjoubi, F., Maaloul, I., Khemakhem, B., and Ben Hamed, S.

Abstract

Bacterial meningitis is a rare complication of myelography.Viridans streptococciare responsible in must cases. The authors described a new case of meningitis due to Streptococcus oralisoccurring more than 3 days after myelography in a 55 year old woman. The probable origin and the mechanism of infection are discussed.

Published
1998
Full Text
View/download PDF

42. Medical treatment of hydatid cysts: activity of albendazole in three patients (22 cysts)

Author

Ben Jemaa, M., Marrakchi, C., Maaloul, I., Mezghanni, S., Khemakhem, B., Ben Arab, N., Ayadi, A., and Ben Hamed, S.

Subjects
*ECHINOCOCCOSIS, *ALBENDAZOLE, *SURGERY, *TOMOGRAPHY
Abstract

Objective: Surgery remains the ideal treatment for hydatid cysts. However, medical treatment with albendazole can be eficient and can, in some circumstances, replace surgery.Patients and methods: We report three cases of multiple hydatid cysts considered inoperable and treated by albendazole. The evaluation of results was based on computerized tomography. Cure was defined as disappearance of the cyst and improvement was defined as a clear decrease (at least 25%) of its size or a clear increase of the cystic density.Results: Cure was obtained in 41% and improvement in 50% of 22 cysts.Comments: The efficiency of chemotherapy in hydatidosis is well proved. Medical treatment is indicated when surgery is not possible and to reduce post surgical dissemination and relapse. Indications, optimal protocols, and criteria of good response should be standardized and evaluated in large series so as to optimize medical treatment. [Copyright &y& Elsevier]

Published
2002
Full Text
View/download PDF

43. A Moment of Mindfulness: Computer-Mediated Mindfulness Practice Increases State Mindfulness

Author

Lynsey Mahmood, Georgina Randsley de Moura, Tim Hopthrow, and Ben Hamed, S

Subjects
Male, 050103 clinical psychology, Computer and Information Sciences, Mindfulness, Psychotherapist, Research Facilities, Adolescent, lcsh:Medicine, Social Sciences, BF, Surveys, Research and Analysis Methods, 050105 experimental psychology, Education, Computer Software, Sociology, Computer software, Medicine and Health Sciences, Psychology, Humans, 0501 psychology and cognitive sciences, Attention, Public and Occupational Health, Computer Networks, lcsh:Science, Internet, Multidisciplinary, Survey Research, Schools, Computers, lcsh:R, 05 social sciences, Cognitive Psychology, Biology and Life Sciences, Research Design, Cognitive Science, lcsh:Q, Female, Research Laboratories, Behavioral and Social Aspects of Health, Research Article, Neuroscience
Abstract

Three studies investigated the use of a 5-minute, computer-mediated mindfulness practice in increasing levels of state mindfulness. In Study 1, 54 high school students completed the computer-mediated mindfulness practice in a lab setting and Toronto Mindfulness Scale (TMS) scores were measured before and after the practice. In Study 2 (N = 90) and Study 3 (N = 61), the mindfulness practice was tested with an entirely online sample to test the delivery of the 5-minute mindfulness practice via the internet. In Study 2 and 3, we found a significant increase in TMS scores in the mindful condition, but not in the control condition. These findings highlight the impact of a brief, mindfulness practice for single-session, computer-mediated use to increase mindfulness as a state.

Published
2016

44. Occipital (V6) and parietal (V6A) areas in the anterior wall of the parieto-occipital sulcus of the macaque: a cytoarchitectonic study

Author

Michela Gamberini, Massimo Matelli, Suliann Ben Hamed, Claudio Galletti, Giuseppe Luppino, Luppino G., Ben Hamed S., Gamberini M., Matelli M., and Galletti C.

Subjects
Posterior parietal cortex, Superior parietal lobule, Neurofilament Proteins, Extrastriate cortex, Parietal Lobe, Image Processing, Computer-Assisted, medicine, Animals, Visual Pathways, Visual Cortex, Neurons, Brain Mapping, General Neuroscience, Parietal lobe, Anatomy, Sulcus, Immunohistochemistry, Macaca fascicularis, Visual cortex, medicine.anatomical_structure, Occipital Lobe, Macaca nemestrina, Occipital lobe, Psychology, Parieto-occipital sulcus, Neuroscience, Software
Abstract

The anterior wall of the parieto-occipital sulcus (POs) of the macaque monkey, classically considered as part of Brodmann's area 19, contains two functionally distinct areas: a ventral, purely visual area, V6, and a dorsal area, V6A, containing visual neurons and neurons related to the control of arm movements. The aim of this study was to establish whether areas V6 and V6A, so far identified only on a functional basis, have a cytoarchitectonic counterpart. The cytoarchitectonic analysis of 13 hemispheres from ten macaque brains, cut along different planes of section, showed that the anterior wall of the POs contains three distinct areas. One is located in the ventralmost part of the wall, another in the dorsalmost part of the wall, and the third occupies an intermediate position. The ventralmost region displays architectonic features typical of the occipital cytoarchitectonic domain, whereas the two dorsal areas display architectonic features typical of the posterior parietal cortex. Analysis of myeloarchitecture and of the distribution of SMI-32 immunoreactivity confirmed the cytoarchitectonic parcellation. Correlation of cytoarchitectonic maps with functional and hodological data strongly suggests that the ventral region corresponds to area V6, whereas the other two regions correspond to different subsectors of V6A, here named V6Av and V6Ad, respectively. The present data are in line with electrophysiological and hodological data, which suggest that area V6 is a classic extrastriate area, whereas V6A is an area of the posterior parietal cortex. They also suggest that V6A includes two separate cortical subdivisions, a view supported by preliminary functional and hodological data that needs further confirmation.

Published
2005

45. Effect of Salvia officinalis aqueous infusion on copper sulfate-induced inflammatory response and oxidative stress imbalance in mice liver and kidney.

Author

Dab H, Ben Hamed S, Jery A, Chehidi A, and Zourgui L

Subjects
Animals, Male, Mice, Tumor Necrosis Factor-alpha metabolism, Tumor Necrosis Factor-alpha blood, Interleukin-6 metabolism, Interleukin-6 blood, Acetylcholinesterase metabolism, Dose-Response Relationship, Drug, Anti-Inflammatory Agents pharmacology, Anti-Inflammatory Agents administration & dosage, Inflammation chemically induced, Inflammation drug therapy, Malondialdehyde metabolism, Superoxide Dismutase metabolism, Oxidative Stress drug effects, Salvia officinalis chemistry, Liver drug effects, Liver metabolism, Copper Sulfate toxicity, Plant Extracts pharmacology, Plant Extracts administration & dosage, Kidney drug effects, Kidney metabolism, Antioxidants pharmacology
Abstract

Extracts of Salvia officinalis ( S. officinalis ) have been described to have many therapeutic properties. However, the effect of S. officinalis on copper sulfate toxicity has not been previously reported. The aim of this study was to investigate the toxicity of copper sulfate and the potential beneficial effects of S. officinalis aqueous infusion on proinflammatory response and antioxidant status. 56 male mice were used and equally divided into 6 groups: control group, copper sulfate treated group (40 mg/kg), S. officinalis aqueous infusion treated groups (200 mg/kg and 400 mg/kg) separately or in combination with copper. IL-6 (interleukine-6) and TNF-α (Tumor necrosis factor alpha) were assessed by Elisa. Catalase (CAT), superoxide dismutase (SOD) and acetylcholinesterase (AChE) activities, malondialdehyde (MDA) and oxygen peroxide levels were determined. Serum biochemical parameters were analyzed. Copper enhanced aspartate aminotransferase (AST), alanine aminotransferase (ALT) and Lactate dehydrogenase (LDH) (p < 0.05). Copper enhances significantly IL-6, TNF-α and MDA levels in liver and kidney and reduced CAT, SOD and AChE activities (p < 0.05). Aqueous infusion of S. officinalis at 400 mg/kg abolished copper-induced changes in AST and ALT activity. S. officinalis aqueous infusion at 200 mg/kg reversed copper-induced IL-6 in kidney and TNF-α in liver at both doses. S. officinalis aqueous infusion at 400 mg/kg restored SOD in kidney and CAT and AChE activities in both liver and kidney. S. officinalis aqueous infusion may be useful in partially ameliorating tissue disorders induced by copper exposure such as inflammatory response, oxidative stress imbalance and organ dysfunction through its phenolic compounds and higher antioxidant capacity.

Published
2024
Full Text
View/download PDF

46. Toward the Development of a Pan-Lyssavirus Vaccine.

Author

Ben Hamed S, Myers JF, Chandwani A, Wirblich C, Kurup D, Paran N, and Schnell MJ

Subjects
Animals, Mice, Rhabdoviridae Infections prevention & control, Rhabdoviridae Infections immunology, Rhabdoviridae Infections veterinary, Rhabdoviridae Infections virology, Vaccines, Synthetic immunology, Vaccines, Synthetic administration & dosage, Female, Viral Vaccines immunology, Glycoproteins immunology, Glycoproteins genetics, Antibodies, Neutralizing immunology, Antibodies, Neutralizing blood, Vaccine Development, Humans, Antigens, Viral immunology, Mice, Inbred BALB C, Lyssavirus immunology, Lyssavirus genetics, Antibodies, Viral immunology, Antibodies, Viral blood, Rabies virus immunology, Rabies virus genetics, Rabies Vaccines immunology, Rabies Vaccines administration & dosage, Rabies prevention & control, Rabies immunology, Rabies virology
Abstract

In addition to the rabies virus (RABV), 16 more lyssavirus species have been identified worldwide, causing a disease similar to RABV. Non-rabies-related human deaths have been described, but the number of cases is unknown, and the potential of such lyssaviruses causing human disease is unpredictable. The current rabies vaccine does not protect against divergent lyssaviruses such as Mokola virus (MOKV) or Lagos bat virus (LBV). Thus, a more broad pan-lyssavirus vaccine is needed. Here, we evaluate a novel lyssavirus vaccine with an attenuated RABV vector harboring a chimeric RABV glycoprotein (G) in which the antigenic site I of MOKV replaces the authentic site of rabies virus (RABVG-cAS1). The recombinant vaccine was utilized to immunize mice and analyze the immune response compared to homologous vaccines. Our findings indicate that the vaccine RABVG-cAS1 was immunogenic and induced high antibody titers against both RABVG and MOKVG. Challenge studies with different lyssaviruses showed that replacing a single antigenic site of RABV G with the corresponding site of MOKV G provides a significant improvement over the homologous RABV vaccine and protects against RABV, Irkut virus (IRKV), and MOKV. This strategy of epitope chimerization paves the way towards a pan-lyssavirus vaccine to safely combat the diseases caused by these viruses.

Published
2024
Full Text
View/download PDF

47. Macaque claustrum, pulvinar and putative dorsolateral amygdala support the cross-modal association of social audio-visual stimuli based on meaning.

Author

Froesel M, Gacoin M, Clavagnier S, Hauser M, Goudard Q, and Ben Hamed S

Subjects
Male, Animals, Female, Facial Expression, Macaca, Photic Stimulation methods, Brain Mapping, Acoustic Stimulation, Vocalization, Animal physiology, Social Perception, Pulvinar physiology, Amygdala physiology, Amygdala diagnostic imaging, Magnetic Resonance Imaging, Auditory Perception physiology, Claustrum physiology, Visual Perception physiology
Abstract

Social communication draws on several cognitive functions such as perception, emotion recognition and attention. The association of audio-visual information is essential to the processing of species-specific communication signals. In this study, we use functional magnetic resonance imaging in order to identify the subcortical areas involved in the cross-modal association of visual and auditory information based on their common social meaning. We identified three subcortical regions involved in audio-visual processing of species-specific communicative signals: the dorsolateral amygdala, the claustrum and the pulvinar. These regions responded to visual, auditory congruent and audio-visual stimulations. However, none of them was significantly activated when the auditory stimuli were semantically incongruent with the visual context, thus showing an influence of visual context on auditory processing. For example, positive vocalization (coos) activated the three subcortical regions when presented in the context of positive facial expression (lipsmacks) but not when presented in the context of negative facial expression (aggressive faces). In addition, the medial pulvinar and the amygdala presented multisensory integration such that audiovisual stimuli resulted in activations that were significantly higher than those observed for the highest unimodal response. Last, the pulvinar responded in a task-dependent manner, along a specific spatial sensory gradient. We propose that the dorsolateral amygdala, the claustrum and the pulvinar belong to a multisensory network that modulates the perception of visual socioemotional information and vocalizations as a function of the relevance of the stimuli in the social context. SIGNIFICANCE STATEMENT: Understanding and correctly associating socioemotional information across sensory modalities, such that happy faces predict laughter and escape scenes predict screams, is essential when living in complex social groups. With the use of functional magnetic imaging in the awake macaque, we identify three subcortical structures-dorsolateral amygdala, claustrum and pulvinar-that only respond to auditory information that matches the ongoing visual socioemotional context, such as hearing positively valenced coo calls and seeing positively valenced mutual grooming monkeys. We additionally describe task-dependent activations in the pulvinar, organizing along a specific spatial sensory gradient, supporting its role as a network regulator., (© 2024 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.)

Published
2024
Full Text
View/download PDF

48. The dynamics of statistical learning in visual search and its interaction with salience processing: An EEG study.

Author

Dolci C, Rashal E, Santandrea E, Ben Hamed S, Chelazzi L, Macaluso E, and Boehler CN

Subjects
Humans, Reaction Time, Visual Perception, Electroencephalography
Abstract

Visual attention can be guided by statistical regularities in the environment, that people implicitly learn from past experiences (statistical learning, SL). Moreover, a perceptually salient element can automatically capture attention, gaining processing priority through a bottom-up attentional control mechanism. The aim of our study was to investigate the dynamics of SL and if it shapes attentional target selection additively with salience processing, or whether these mechanisms interact, e.g. one gates the other. In a visual search task, we therefore manipulated target frequency (high vs. low) across locations while, in some trials, the target was salient in terms of colour. Additionally, halfway through the experiment, the high-frequency location changed to the opposite hemifield. EEG activity was simultaneously recorded, with a specific interest in two markers related to target selection and post-selection processing, respectively: N2pc and SPCN. Our results revealed that both SL and saliency significantly enhanced behavioural performance, but also interacted with each other, with an attenuated saliency effect at the high-frequency target location, and a smaller SL effect for salient targets. Concerning processing dynamics, the benefit of salience processing was more evident during the early stage of target selection and processing, as indexed by a larger N2pc and early-SPCN, whereas SL modulated the underlying neural activity particularly later on, as revealed by larger late-SPCN. Furthermore, we showed that SL was rapidly acquired and adjusted when the spatial imbalance changed. Overall, our findings suggest that SL is flexible to changes and, combined with salience processing, jointly contributes to establishing attentional priority., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Published
2024
Full Text
View/download PDF

49. Effect of drought stress and subsequent re-watering on the physiology and nutrition of Pistacia vera and Pistacia atlantica .

Author

Ben Hamed S, Lefi E, and Chaieb M

Subjects
Humans, Droughts, Photosynthesis, Chlorophyll, Plant Leaves, Pistacia
Abstract

Arid and semi-arid regions are characterised by extreme conditions including drought stress and salinity. These factors profoundly affect the agricultural sector. The objective of this work is to study the effect of drought and re-watering on leaf gas exchange, chlorophyll fluorescence and mineral nutrition in Pistacia vera and Pistacia atlantica . Water stress was applied to individuals of P. vera and P. atlantica for 23days, followed by rehydration for 7days. The results showed a clear reduction in water relations, leaf gas exchange and chlorophyll content in P. vera . Compared to P. vera , P. atlantica maintained less affected water status, total chlorophyll content, leaf gas exchange and chlorophyll fluorescence, stable Zn and Fe proportion, and even elevated K and Cu. The changes in the chlorophyll fluorescence parameter were manifested particularly at the maximal fluorescence (Fm). In contrast, no change was recorded at the minimal fluorescence (F0). After re-hydration, although water status was fully recovered in both species, stomatal conductance (gs), net photosynthesis (A ) and transpiration rate (E ) remain with lower values than the well-watered seedlings. P. atlantica was better adapted to drought stress than P. vera .

Published
2024
Full Text
View/download PDF

50. Integrated effects of top-down attention and statistical learning during visual search: An EEG study.

Author

Dolci C, Boehler CN, Santandrea E, Dewulf A, Ben-Hamed S, Macaluso E, Chelazzi L, and Rashal E

Subjects
Humans, Reaction Time physiology, Evoked Potentials, Electroencephalography, Visual Perception physiology, Learning physiology, Cues
Abstract

The present study aims to investigate how the competition between visual elements is solved by top-down and/or statistical learning (SL) attentional control (AC) mechanisms when active together. We hypothesized that the "winner" element that will undergo further processing is selected either by one AC mechanism that prevails over the other, or by the joint activity of both mechanisms. To test these hypotheses, we conducted a visual search experiment that combined an endogenous cueing protocol (valid vs. neutral cue) and an imbalance of target frequency distribution across locations (high- vs. low-frequency location). The unique and combined effects of top-down control and SL mechanisms were measured on behaviour and amplitudes of three evoked-response potential (ERP) components (i.e., N2pc, P1, CNV) related to attentional processing. Our behavioural results showed better performance for validly cued targets and for targets in the high-frequency location. The two factors were found to interact, so that SL effects emerged only in the absence of top-down guidance. Whereas the CNV and P1 only displayed a main effect of cueing, for the N2pc we observed an interaction between cueing and SL, revealing a cueing effect for targets in the low-frequency condition, but not in the high-frequency condition. Thus, our data support the view that top-down control and SL work in a conjoint, integrated manner during target selection. In particular, SL mechanisms are reduced or even absent when a fully reliable top-down guidance of attention is at play., (© 2023. The Author(s).)

Published
2023
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results