Neuroscience Meeting Research Articles

A Student Perspective on the 18th Monitoring Molecules in Neuroscience Meeting in Lyon.

After being postponed twice due to the global COVID-19 pandemic, approximately 200 scientists gathered in Lyon, France, in late June 2022 for the 18th Biennial Monitoring Molecules in Neuroscience (MMiN) Research Conference. Although there were unprecedented challenges involved with coordinating the 18th MMiN conference, the meeting was a huge success. The meeting provided a wonderful opportunity for young neuroscientists to network and learn about the current state of molecular monitoring in neuroscience research. The topics spanned advancements in well-established analytical techniques to novel method development. Some of the noteworthy techniques expediting our understanding of circuit-level neurochemical function include multiplexed detection of numerous neurochemicals, well-established sensors leveraging enzymes and other biologic components, and the development of diverse, customizable genetically encoded sensors.

Racial equity and inclusion still lacking in neuroscience meetings.

Racial equity and inclusion still lacking in neuroscience meetings.

New directions in modelling dysregulated reward seeking for food and drugs

Behavioral models are central to behavioral neuroscience. To study the neural mechanisms of maladaptive behaviors (including binge eating and drug addiction), it is essential to develop and utilize appropriate animal models that specifically focus on dysregulated reward seeking. Both food and cocaine are typically consumed in a regulated manner by rodents, motivated by reward and homeostatic mechanisms. However, both food and cocaine seeking can become dysregulated, resulting in binge-like consumption and compulsive patterns of intake. The speakers in this symposium for the 2021 International Behavioral Neuroscience Meeting utilize behavioral models of dysregulated reward-seeking to investigate the neural mechanisms of binge-like consumption, enhanced cue-driven reward seeking, excessive motivation, and continued use despite negative consequences. In this review, we outline examples of maladaptive patterns of intake and explore recent animal models that drive behavior to become dysregulated, including stress exposure and intermittent access to rewards. Lastly, we explore select behavioral and neural mechanisms underlying dysregulated reward-seeking for both food and drugs.

Charismatic and Visionary Leaders.

Charismatic leaders play fascinating roles in society, for good and for ill. In the United States, we are aware of the power of Martin Luther King and John Lewis in the fight for equal rights, and every country will have its heroes in its struggles for freedom. And, we are equally aware of the impact of despots who have led to terrible miscarriages of justice. We are less accustomed to think of the roles of charismatic leaders in our scientific communities, as we prefer to believe that we all “follow the science” rather than the scientist! Nonetheless, my eyes were opened to the impact of personal charisma in science at the Society for Neuroscience Meeting in 1980. I was chatting with a very fine membrane biophysicist when Eric Kandel walked by and my colleague said, “Kandel is my hero.” I was surprised, as the work my friend did was detailed characterization of membrane currents, far from the grand sweep of Kandel’s work. And when I asked my friend why he revered Kandel, he said that he didn’t dare to dream to big picture questions but restricted himself to elucidating the details of cellular mechanisms precisely because of his own lack of visionary courage. My friend valued Kandel, not for the details of his experiments, but for articulating that someday it would be possible to establish the molecular and cellular bases of learning and memory. I learned from this conversation that scientists add value or are destructive to our collective enterprise in disparate ways. Henry Markram is one of these fascinating individuals who dared to set himself and our community the most ambitious of goals. I first met Markram early in his career when he was doing breathtaking and virtuoso work in brain slices, first as a postdoc and then as …

Despite calls to action, Black scientists remain underrepresented at neuroscience meetings

Despite calls to action, Black scientists remain underrepresented at neuroscience meetings

29th Annual Computational Neuroscience Meeting: CNS*2020

P38 Priors based on abstract rules modulate the encoding of pure tones in the subcortical auditory pathwayAlejandro Tabas1, Glad Mihai1, Stefan Kiebel2, Robert Trampel3, Katharina von Kriegstein4 1Max Planck Institute for Human Cognitive and Brain Sciences, Research Group in Neural Mechanisms of Human Communication, Leipzig, Germany; 2Technische Univerität Dresden, Chair of Neuroimage, Dresden, Germany; 3Max Planck Institute for Human Cognitive and Brain Sciences, Department of Neurophysics, Leipzig, Germany; 4Technische Univerität Dresden, Chair of Cognitive and Clinical Neuroscience, Dresden, Germany Correspondence: Alejandro Tabas (alextabas@gmail.com)BMC Neuroscience 2020, 21(Suppl 1):P38Sensory pathways efficiently transmit information by adapting the neural responses to the local statistics of the sensory input. The predictive coding framework suggests that sensory neurons constantly match the incoming stimuli against an internal prediction derived from a generative model of the sensory input. Although predictive coding is generally accepted to underlay cortical sensory processing, the role of predictability in subcortical sensory coding is still unclear. Several studies have shown that single neurons and neuronal ensembles of the subcortical sensory pathway nuclei exhibit stimulus specific adaptation (SSA), a phenomenon where neurons adapt to frequently occurring stimuli (standards) yet show restored responses to a stimulus with deviating characteristics from the standard (deviant). Although neurons showing SSA are often interpreted as encoding prediction error, computational models to date have successfully explained SSA in terms of local network effects based on synaptic fatigue.Here, we first introduce a novel experimental paradigm where abstract rules are used to manipulate predictability. 19 human participants listened to sequences of pure tones consisting on seven standards and one deviant while we recorded mesoscopic responses in auditory thalamus and auditory midbrain using 7-Tesla functional MRI. In each sequence, the deviant was constrained to occur once and only once, and always in locations 4, 5 or 6. Although the three locations were equiprobable at the beginning of the trial, the conditional probability of hearing a deviant in location n after hearing n-1 standards is 1/3, 1/2, and 1, for deviant locations 4, 5, and 6, respectively.This paradigm yields different outcomes for habituation and predictive coding: if adaptation is driven by local habituation only, the three deviants should elicit similar neuronal responses; however, if it is predictive coding that entails adaptation, the neuronal responses to each deviant should depend on their abstract predictability. Our data showed that the responses to the deviants were strongly driven by abstract expectations, indicating that predictive coding is the main mechanism underlying mesoscopic SSA in the subcortical pathway. These results are robust even at the single-subject level.Next, we developed a new model of pitch encoding for pure tones following the main directives of predictive coding. The model comprises two layers whose dynamics reflect two different levels of abstraction. The lower layer receives its inputs from the auditory nerve and makes use of the finite bandwidth of the peripheral filters to decode pitch fast and robustly. The second layer holds a sparse representation that integrates the activity in the first layer only once the pitch decision has been made. Top-down afferents from the upper layer reinforce the pitch decision and accept the inclusion of priors that facilitate the decoding of predictable tones.Without the inclusion of priors, the model explains the key elements of SSA in animal recordings at the single-neuron level, as well as the main phenomenology of its mesoscopic representation. The inclusion of priors reflecting the abstract rules described in our paradigm facilitates the decoding of tones according to their predictability, effectively modulating the responses at the mesoscopic level. This modulation affects the mesoscopic fields generated during pitch encoding, fully explaining our experimental data.Fig. 1Top: z-scores of the BOLD responses to standards and deviants in the left auditory thalamus. Similar responses were recorded in the right auditory thalamus and bilateral auditory midbrain. Bottom: average model predictions under the habituation only (without informed priors) and predictive coding (with informed priors) scenariosFull size image

The International conference on Neuroscience and 36th Annual Meeting of Indian Academy of Neurosciences, 2018.

The International conference on Neuroscience and 36th Annual Meeting of Indian Academy of Neurosciences, 2018.

Modulatory effects of prefrontal theta burst stimulation on motor task-related brain activity

Modulatory effects of prefrontal theta burst stimulation on motor task-related brain activity

25th Annual Computational Neuroscience Meeting: CNS-2016.

25th Annual Computational Neuroscience Meeting: CNS-2016.

Palmitoylethanolamide, a Special Food for Medical Purposes, in the Treatment of Chronic Pain: A Pooled Data Meta-analysis

A growing body of evidence suggests that neuroinflammation, which is characterized by infiltration of immune cells, activation of mast cells and glial cells, and production of inflammatory mediators in the peripheral and central nervous systems, has an important role in the induction and maintenance of chronic pain. These findings support the notion that new therapeutic opportunities for chronic pain might be based on anti-inflammatory and pro-resolving mediators that act on immune cells, in particular mast cells and glia, to mitigate or abolish neuroinflammation. Among anti-inflammatory and pro-resolving lipid mediators, palmitoylethanolamide (PEA) has been reported to down-modulate mast cell activation and to control glial cell behaviors. The aim of this study was to perform a pooled meta-analysis to evaluate the efficacy and safety of micronized and ultra-micronized palmitoylethanolamide (PEA) on pain intensity in patients suffering from chronic and/or neuropathic pain. Pooled data analysis consisting of double-blind, controlled, and open-label clinical trials. Double-blind, controlled, and open-label clinical trials were selected consulting the PubMed, Google Scholar, and Cochrane databases, and proceedings of neuroscience meetings. The terms chronic pain, neuropathic pain, and micronized and ultra-micronized PEA were used for the search. Selection criteria included availability of raw data and comparability between tools used to diagnose and assess pain intensity. Raw data obtained by authors were pooled in one database and analyzed by the Generalized Linear Mixed Model. The changes in pain over time, measured by comparable tools, were also assessed by linear regression post-hoc analysis and the Kaplan-Meier estimate. Twelve studies were included in the pooled meta-analysis, 3 of which were double-blind trials comparing active comparators vs placebo, 2 were open-label trials vs standard therapies, and 7 were open-label trials without comparators. Results showed that PEA elicits a progressive reduction of pain intensity significantly higher than control. The magnitude of reduction equals 1.04 points every 2 weeks with a 35% response variance explained by the linear model. In contrast, in the control group pain, reduction intensity equals 0.20 points every 2 weeks with only 1% of the total variance explained by the regression. The Kaplan-Meier estimator showed a pain score = 3 in 81% of PEA treated patients compared to only 40.9% in control patients by day 60 of treatment. PEA effects were independent of patient age or gender, and not related to the type of chronic pain. Noteworthy, serious adverse events related to PEA were not registered and/or reported in any of the studies. These results confirm that PEA might represent an exciting, new therapeutic strategy to manage chronic and neuropathic pain associated with neuroinflammation.

Optical imaging of prefrontal cortex hemodynamic response in executive function induced by increased cardiovascular activity

Article accompanying a poster presentation for the 2014 Annual Computational Neuroscience Meeting. This article discusses optical imaging of prefrontal cortex hemodynamic response in executive function induced by increased cardiovascular activity.

Computational optimization problems in social interaction and empathic social emotion

Article accompanying a poster presentation for the 2014 Annual Computational Neuroscience Meeting. This article discusses computational optimization problems in social interaction and empathic social emotion.

Modeling the effects of neuronal morphology on dendritic chloride diffusion and GABAergic inhibition

Poster presentation at the Twenty Third Annual Computational Neuroscience Meeting: CNS*2014 Quebec City, Canada. 26-31 July 2014. Gamma-aminobutyric acid receptors (GABAARs) are ligand-gated chloride (Cl−) channels which mediate the majority of inhibitory neurotransmission in the CNS. Spatiotemporal changes of intracellular Cl− concentration alter the concentration gradient for Cl− across the neuronal membrane and thus affect the current flow through GABAARs and the efficacy of GABAergic inhibition. However, the impact of complex neuronal morphology on Cl− diffusion and the redistribution of intracellular Cl− is not well understood. Recently, computational models for Cl− diffusion and GABAAR-mediated inhibition in realistic neuronal morphologies became available [1-3]. Here we have used computational models of morphologically complex dendrites to test the effects of spines on Cl− diffusion. In all dendritic morphologies tested, spines slowed down longitudinal Cl− diffusion along dendrites and decreased the amount and spatial spread of synaptically evoked Cl− changes. Spine densities of 2-10 spines/µm decreased the longitudinal diffusion coefficient of Cl− to 80-30% of its value in smooth dendrites, respectively. These results suggest that spines are able to limit short-term ionic plasticity [4] at dendritic GABAergic synapses.

The emergence of cohorts of co-active neurons in random recurrent networks provides a mechanism for orientation and direction selectivity

Poster presentation at The Twenty Third Annual Computational Neuroscience Meeting: CNS*2014 Quebec City, Canada. 26-31 July 2014: We study random strongly heterogeneous recurrent networks of firing rate neurons, introducing the notion of cohorts: groups of co-active neurons, who compete for firing with one another and whose presence depends sensitively on the structure of the input. The identities of neurons recruited to and dropped from an active cohort changes smoothly with varying input features. We search for network parameter regimes in which the activation of cohorts is robust yet easily switchable by the external input and which exhibit large repertoires of different cohorts. We apply these networks to model the emergence of orientation and direction selectivity in visual cortex. We feed these random networks with a set of harmonic inputs that vary across neurons only in their temporal phase, mimicking the feedforward drive due to a moving grating stimulus. The relationship between the phases that carries the information about the orientation of the stimulus determines which cohort of neurons is activated. As a result the individual neurons acquire non-monotonic orientation tuning curves which are characterized by high orientation and direction selectivity. This mechanism of emergence for direction selectivity differs from the classical motion detector scheme, which is based on the nonlinear summation of the time-shifted inputs. In our model these two mechanisms coexist in the same network, but can be distinguished by their different frequency and contrast dependences. In general, the mechanism we are studying here converts temporal phase sequence into population activity and could therefore be used to extract and represent also various other relevant stimulus features.

Abstracts: The 22nd Annual Meeting of the Israel Society for Neuroscience (ISFN) & The 2nd Bi national Italy-Israel Neuroscience Meeting

Abstracts: The 22nd Annual Meeting of the Israel Society for Neuroscience (ISFN) & The 2nd Bi national Italy-Israel Neuroscience Meeting

Conferences and Conclusions at the Year's Close

As we head towards the end of the year, it is a good time to reflect back on the most important stories and developments of the last twelve months, particularly in the light of the recent conference held by the Society for Neuroscience, which clearly demonstrated some of the ways in which the field is changing and growing. At the same time, our thoughts may also turn towards the year ahead and the new questions and breakthroughs that it may bring. The Year in Review Quantum neuroscience has generated some intriguing results in 2013, and it has also expanded into the public consciousness, with stories on quantum effects in nature being publicized by a number of newspapers. NeuroQuantology has itself published some interesting work over the course of the year, including the special supplement on Everett's Quantum Mechanics, and articles on neurophilosophy, consciousness and the quantum model of reality. The range of topics covered in NeuroQuantology has been vast, and with such diverse work going on, it is hardly surprising that quantum biology is becoming a term that a growing number of people are learning to recognize. Neuroscience - 2013 The year 2013 has produced some interesting and important advances in the fields of neuroscience and quantum biology, many of which fell under discussion during the Neuroscience 2013 conference, which was held between November 9 and 13 in San Diego, California. The conference, which was organized by the Society for Neuroscience, attracted more than 30,000 attendees from across the globe, making it one of the largest neuroscience meetings in the world. Among the research stories from the conference that made the biggest impact, particularly in the mainstream media, was the work conducted on the neuroscience of drug addiction. Findings presented at the conference included work into the use of magnetic stimulation to enable people to quit smoking, and stimulation of the subthalamic nucleus of rats to reduce their appetite for heroin. Other researchers had focused on the motivation of addicts and the long-term effects of vicodin use and other addictive substances. Drug abuse was described as causing improper regulation of the stress response in the brain, potentially increasing the desire to continue taking drugs, while individuals who had experienced damage to the insula were found to be less prone to gambling addiction. Other highlights of the conference included a lecture on the relationship between neuroscience and society, given by the president of Pixar, Ed Catmull, and the Symposium on Creativity, in which artists and scientists came together to discuss how neuroscience can help us to understand the creative process. The conference also gave attendees the chance to look forward and consider how the field of neuroscience is changing, with presentations on the new brain initiatives being created in both the United States and Europe, and a special series of lectures on the idea of creating a map of the entire network of cells making up the brain. Quantum Biology at Neuroscience - 2013 The broad focus of the conference enabled presenters to cover a wide range of topics in neuroscience, and although the majority of the work was dedicated to more traditional views of neuroscience, there were some presentations that explored quantum effects in the brain and in experimental methods, as well as other emerging approaches to neuroscience. The use of quantum dots was discussed by several research teams, indicating that this type of technology is becoming more widespread within neuroscience, although the study of quantum effects in the brain was not common among the studies presented at the meeting. As quantum neuroscience continues to produce the types of results that have been reported in Neuroquantology and elsewhere during the last year, we may hope to see more presentations on quantum effects in the brain being made at these mainstream neuroscience events, rather than being restricted to the more specialized meetings targeted at quantum biologists. Neuroscience - 2014 Looking back over the last year, it is clear that some important advances have been made in neuroscience and quantum biology, many of which were presented at the Society of Neuroscience's conference, but there are still many more questions left unanswered for us to puzzle over in 2014 and beyond. The increasing familiarity of neuroscientists with quantum ideas, particularly in the form of the use of quantum dots and similar technologies, may help to increase interest in the field over the next year, and quantum biology could well be better represented at next year's Society of Neuroscience meeting, which will be held between November 15 and 19 in Washington DC.

Passages 2014

Passages 2014

Peri-microsaccadic modulation of visual activity in the primate superior colliculus: dependence on movement direction and neuronal cell type

Perceptual thresholds are elevated around the time of microsaccades. A neural correlate for such ‘microsaccadic suppression’ has recently been described in superior colliculus (SC) (Hafed & Krauzlis, 2010), but the dependence of this ‘suppression’ on visual location, microsaccade direction, or neuronal cell type is currently unknown. Here we tested for such dependence, to fully understand how microsaccades affect perceptual performance. We recorded SC activity from one monkey fixating a white spot over a gray background. Inside a neuron’s response field (RF), we displayed a square (1-5 deg) containing a vertical sine-wave grating (2.2 cpd) for ~250 ms. We measured peak neuronal activity 50-150 ms after grating onset and divided trials into three groups: 1) the grating appeared without microsaccade <300 ms from its onset; 2) the same grating appeared <100 ms before microsaccades; 3) the grating appeared <100 ms after microsaccades. We recorded ‘visual-motor’ and ‘visual-only’ SC neurons. Across 49 neurons (29 visual-motor and 20 visual-only), most (~94%) exhibited peri-microsaccadic modulation of visual activity. The most common observation was strong suppression for stimuli appearing right after microsaccades (~90% of visual-motor neurons and ~65% of visual-only neurons). For stimuli appearing before microsaccades, the neuronal modulations depended both on cell type and movement direction. Specifically, for microsaccades away from the RF location, most visual-motor neurons (~62%) were suppressed; for microsaccades toward the RF, ~38% showed suppression and ~24% enhancement. For visual-only neurons, only ~5% showed suppression for stimuli before microsaccades and ~70% showed enhancement, irrespective of microsaccade direction. Thus, peri-microsaccadic modulation of SC visual activity is pervasive, with specific differences between neuronal cell types. Besides providing a more complete characterization of peri-microsaccadic changes in vision, our work reveals a possible neural basis for recent observations that microsaccade direction has a strong, eccentricity-dependent influence on perceptual performance (Hafed, Society for Neuroscience Meeting, 2012). Meeting abstract presented at VSS 2013

Neuronal avalanches change from wakefulness to deep sleep - a study of intracranial depth recordings in humans

Poster presentation: Twenty Second Annual Computational Neuroscience Meeting: CNS*2013. Paris, France. 13-18 July 2013. Neuronal dynamics differs between wakefulness and sleep stages, so does the cognitive state [1]. In contrast, a single attractor state, called self-organized critical (SOC), has been proposed to govern human brain dynamics for its optimal information coding and processing capabilities [2]. Here we address two open questions: First, does the human brain always operate in this computationally optimal state, even during deep sleep? Second, previous evidence for SOC was based on activity within single brain areas [3-5], however, the interaction between brain areas may be organized differently. Here we asked whether the interaction between brain areas is SOC. We addressed these questions by characterizing neuronal avalanches [3] - spatiotemporal waves of enhanced activity - from up to 61 local field potential (LFP) channels of intracranial depth recordings (5 human patients, two recording nights each, summing up to ~100h of recordings). The recording contacts were distributed inside the entire brain. Note that ~60 contacts are sufficient to avoid major subsampling effects: Subsampling may heavily distort results in SOC systems due to an insufficient number of sampling sites [5]. In addition, we compared the experimental results to results from a subsampled SOC model of integrate- and fire neurons, which can be tuned to the sub- and supercritical regime. We show that avalanche distributions closely follow a power law - the hall mark feature of SOC systems. This result held for each vigilance state, and independent of the threshold and the temporal scale. This indicates first that the interaction between brain areas are close to SOC, and second that the dynamics of all cognitive states, from wakefulness to deep sleep are close to SOC. Minor differences between cognitive states are, however, reflected in the avalanche distributions: Slow wave sleep (s3/s4) showed larger and longer neuronal avalanches than REM sleep, while wakefulness showed intermediate ones (p < 0.05). The SOC neuronal model, together with the data, suggested first that these differences are mediated by global but tiny changes in synaptic strength, and second, that the changes with vigilance states reflect small deviations from criticality to the subcritical regime, implying that the human brain does not operate in the SOC state proper - contrary to previous believes. Independent of criticality, the analysis confirmed that slow wave sleep shows increased correlations between cortical areas, and revealed that REM sleep shows more fragmented cortical dynamics.

Detection of neuronal signatures by means of data-driven tomography

Abstracts from Twenty Second Annual Computational Neuroscience Meeting: CNS*2013. Paris, France. 13-18 July 2013