Jean-Marc Fellous's research while affiliated with The University of Arizona and other places

Publications (140)

Article
Spatially firing “place cells” within the hippocampal CA1 region form internal maps of the environment necessary for navigation and memory. In rodents, these neurons have been almost exclusively studied in small environments (<4 m²). It remains unclear how place cells encode a very large open 2D environment that is commensurate with the natural env...
Preprint
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Spatially firing 'place cells' within the hippocampal CA1 region form internal maps of the environment necessary for navigation and memory. In rodents, these neurons have been almost exclusively studied in small environments (<4 m2 8 ). It remains unclear how place cells encode a very large open 2D environment, which is more analogous to the natura...
Article
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Homoeostatic metaplasticity is a neuroprotective physiological feature that counterbalances Hebbian forms of plasticity to prevent network destabilization and hyperexcitability. Recent animal models highlight dysfunctional homoeostatic metaplasticity in the pathogenesis of Alzheimer’s disease. However, the association between homoeostatic metaplast...
Article
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Classic studies have shown that place cells are organized along the dorsoventral axis of the hippocampus according to their field size, with dorsal hippocampal place cells having smaller field sizes than ventral place cells. Studies have also suggested that dorsal place cells are primarily involved in spatial navigation, while ventral place cells a...
Article
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Autonomous motivated spatial navigation in animals or robots requires the association between spatial location and value. Hippocampal place cells are involved in goal-directed spatial navigation and the consolidation of spatial memories. Recently, Gauthier and Tank (Neuron 99(1):179–193, 2018. https://doi.org/10.1016/j.neuron.2018.06.008) have iden...
Article
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The use of Artificial Intelligence and machine learning in basic research and clinical neuroscience is increasing. AI methods enable the interpretation of large multimodal datasets that can provide unbiased insights into the fundamental principles of brain function, potentially paving the way for earlier and more accurate detection of brain disorde...
Article
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As rats learn to search for multiple sources of food or water in a complex environment, they generate increasingly efficient trajectories between reward sites. Such spatial navigation capacity involves the replay of hippocampal place-cells during awake states, generating small sequences of spatially related place-cell activity that we call "snippet...
Article
Background: The precise detection of cortical sleep spindles is critical to basic research on memory consolidation in rodents. Previous research using automatic spindle detection algorithms often lacks systematic parameter variations and validations. New method: We present a method to systematically tune and validate algorithm parameters in auto...
Preprint
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As rats learn to search for multiple sources of food or water in a complex environment, they generate increasingly efficient trajectories between reward sites, across multiple trials. This optimization capacity has been characterized in the Traveling Salesrat Problem (TSP) ( de Jong et al (2011) . Such spatial navigation capacity involves the repla...
Article
A large body of evidence shows that the hippocampus is necessary for successful spatial navigation. Various studies have shown anatomical and functional differences between the dorsal (DHC) and ventral (VHC) portions of this structure. The DHC is primarily involved in spatial navigation and contains cells with small place fields. The VHC is primari...
Article
Background: Understanding the neural substrate of information encoding and processing requires a precise control of the animal's behavior. Most of what has been learned from the rodent navigational system results from relatively simple tasks in which the movements of the animal is controlled by corridors or walkways, passive movements, treadmills...
Article
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The context in which learning occurs is sufficient to reconsolidate stored memories and neuronal reactivation may be crucial to memory consolidation during sleep. The mechanisms of context-dependent and sleep-dependent memory (re)consolidation are unknown but involve the hippocampus. We simulated memory (re)consolidation using a connectionist model...
Article
Post-traumatic stress disorder (PTSD) is in part due to a deficit in memory consolidation and extinction. Oxytocin (OXT) has anxiolytic effects and promotes prosocial behaviors in both rodents and humans, and evidence suggests that it plays a role in memory consolidation. We studied the effects of administered OXT and social co-housing in a rodent...
Article
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Despite the high prevalence of stress exposure healthy adaptation or resilience is a common response. Theoretical work and recent empirical evidence suggest that a robust reward system, in part, supports healthy adaptation by preserving positive emotions even under exceptionally stressful circumstances. We tested this prediction by examining empiri...
Article
There has been extensive research in recent years on the multi-scale nature of hippocampal place cells and entorhinal grid cells encoding which led to many speculations on their role in spatial cognition. In this paper we focus on the multi-scale nature of place cells and how they contribute to faster learning during goal-oriented navigation when c...
Article
In a rest period immediately after a task, neurons in the hippocampus, neocortex and striatum exhibit spatiotemporal correlation patterns resembling those observed during the task. This reactivation has been proposed as a neurophysiological substrate for memory consolidation. We provide new evidence that rodent VTA neurons are selective for differe...
Article
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There is strong evidence that hippocampal memory returns to a labile state upon reactivation, initiating a reconsolidation process that restabilizes it and allows for its updating. Normal aging is associated with deficits in episodic memory processes. However, the effects of aging on memory reconsolidation and its neural substrate remain largely un...
Article
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Most conceptual and computational models assume that synaptic transmission is reliable, a sim- plification rarely substantiated by data. The functional consequences of the recruitment of high and low initial release probability synapses on the reliability and precision of their postsynaptic targets are studied in a multi-compartmental model of a hi...
Article
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Context-based memory reconsolidation has been studied in human and animal models [1]. In these paradigms, subjects learn two lists of items on two different days and are asked to recall the first list on day 3. Subjects who learn the two lists in the same spatial context make significantly more errors on day 3 than subjects who learn the lists in d...
Article
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The investigation of neural interactions is crucial for understanding information processing in the brain. Recently an analysis method based on information geometry (IG) has gained increased attention, and the property of the pairwise IG measure has been studied extensively in relation to the two-neuron interaction. However, little is known about t...
Article
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Because most rewarding events are probabilistic and changing, the extinction of probabilistic rewards is important for survival. It has been proposed that the extinction of probabilistic rewards depends on arousal and the amount of learning of reward values. Midbrain dopamine neurons were suggested to play a role in both arousal and learning reward...
Article
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The characterization of functional network structures among multiple neurons is essential to understanding neural information processing. Information geometry (IG), a theory developed for investigating a space of probability distributions has recently been applied to spike-train analysis and has provided robust estimations of neural interactions. A...
Conference Paper
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The medial temporal lobe-which includes the hippocampus, as well as perirhinal, parahippocampal, and entorhinal cortices-is required for declarative memory. We focus on the role of the perirhinal cortex (PRC) in relaying semantic representations from temporal cortex to the ventral hippocampus. It has been argued that the PRC is more than a simple r...
Article
The rodent hippocampus and entorhinal cortex contain spatially-modulated cells that serve as the basis for spatial coding. Both medial entorhinal grid cells and hippocampal place cells have been shown to encode spatial information across multiple spatial scales that increase along the dorsoventral axis of these structures. Place cells near the dors...
Article
Posttraumatic stress disorder (PTSD) is a very debilitating disease refractory to current treatment with selective serotonin reuptake inhibitors (SSRIs) in up to 30 percent of patients, illustrating the need for new treatments of PTSD. Neuroimaging studies have shown increased activity of the amygdala of patients with PTSD. To investigate amygdala...
Article
Anthropomorphism in impressions of animals is commonplace, and this generalization from humans to animals is one example of a broader tendency to generalize from adaptively significant categories when judging specific exemplars. Although anthropomorphism may lead to unlikely or incorrect judgments, it fostered accurate sex-differentiation of macaqu...
Article
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The human hippocampus receives distinct signals via the lateral entorhinal cortex, typically associated with object features, and the medial entorhinal cortex, associated with spatial or contextual information. The existence of these distinct types of information calls for some means by which they can be managed in an appropriate way, by integratin...
Data
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Additional examples of patterns correlated across the stimulus duration. Each of six panels (A–F) has the same organization. The left and middle graphs are rastergrams, as in Figures 4A and 4B, respectively. The right-most panel displays voltage traces. The time interval was divided into 4 segments, which are indicated by thick vertical lines in th...
Data
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Slow currents generate long-lasting patterns. We show the (A,B) voltage traces and (C,D) value of the gating variable z of the slow current as a function of time. Panels B and D are a close-up of C and D, respectively. There are 10 traces, each corresponding to a different initial z value (visible as different starting points at t = 0 in panel C)....
Data
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Bifurcation structure in the presence of slow currents. (A) Spike trains for different initial values of z. Approximately two patterns are reached. (B) Spike trains as a function of depolarizing current, bifurcations still occur and (C) represent sites of enhanced noise sensitivity. See Methods and Experimental procedures for model parameters. (PDF...
Article
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The response of a neuron to repeated somatic fluctuating current injections in vitro can elicit a reliable and precisely timed sequence of action potentials. The set of responses obtained across trials can also be interpreted as the response of an ensemble of similar neurons receiving the same input, with the precise spike times representing synchr...
Article
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Post-traumatic stress disorder (PTSD) is an anxiety disorder of considerable prevalence in individuals who have experienced a traumatic event. Studies of the neural substrate of this disorder have focused on the role of areas such as the hippocampus, the amygdala and the medial prefrontal cortex. We show that the ventral tegmental area (VTA), which...
Conference Paper
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Continuous attractor networks have been proposed to explain a variety of phenomena, including working memory and rodent entorhinal grid cells [1,2]. Typically, such networks consist of spatially-structured lattices of neurons in one or two dimensions with long-range inhibition and short-range excitation, which causes the network activity to spontan...
Article
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Grid cells in the medial entorhinal cortex (mEC) and place cells in the hippocampus are paradigms for population coding of spatial information [1]. Both the spatially-periodic firing fields of grid cells and the spatially localized firing fields of place cells show systematic increases in spatial scale along the dorso-ventral axes of the mEC and hi...
Article
We describe a spatial cognition model based on the rat's brain neurophysiology as a basis for new robotic navigation architectures. The model integrates allothetic (external visual landmarks) and idiothetic (internal kinesthetic information) cues to train either rat or robot to learn a path enabling it to reach a goal from multiple starting positio...
Article
We present a model that describes the generation of the spatial (grid fields) and temporal (phase precession) properties of medial entorhinal cortical (MEC) neurons by combining network and intrinsic cellular properties. The model incorporates network architecture derived from earlier attractor map models, and is implemented in 1D for simplicity. P...
Article
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There is strong evidence that reactivation of a memory returns it to a labile state, initiating a restabilization process termed reconsolidation, which allows for updating of the memory. In this study we investigated reactivation-dependent updating using a new positively motivated spatial task in rodents that was designed specifically to model a hu...
Article
Full-text available
Rodent spatial navigation requires the dynamic evaluation of multiple sources of information, including visual cues, self-motion signals and reward signals. The nature of the evaluation, its dynamics and the relative weighting of the multiple information streams are largely unknown and have generated many hypotheses in the field of robotics. We use...
Article
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The hippocampus stores information during the acquisition of new memory episodes. These memories are replayed during sleep as part of a memory consolidation process. The neural mechanisms underlying these reactivations are currently under investigation. One hypothesis is that reactivation occurs as a result of local attractor dynamics within the st...
Article
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Neurons in sensory systems convey information about physical stimuli in their spike trains. In vitro, single neurons respond precisely and reliably to the repeated injection of the same fluctuating current, producing regions of elevated firing rate, termed events. Analysis of these spike trains reveals that multiple distinct spike patterns can be i...
Article
An important problem in neuroscience is that of constructing quantitative measures of the similarity between neural spike trains. These measures can be used, for example, to assess the reliability of the response of a single neuron to repeated stimulus presentations, or to uncover relationships in the firing patterns of multiple neurons in a popula...
Conference Paper
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Complementary learning systems (CLS) theory describes how the hippocampal and cortical contributions to recognition memory are a direct result of their architectural and computational specializations. In this paper we model a further refinement of CLS that features separate handling of inputs from the dorsal and ventral posterior cortices, and pres...
Article
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Reinforcement learning is ubiquitous. Unlike other forms of learning, it involves the processing of fast yet content-poor feedback information to correct assumptions about the nature of a task or of a set of stimuli. This feedback information is often delivered as generic rewards or punishments, and has little to do with the stimulus features to be...
Article
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Fast inhibitory synaptic inputs, which cause conductance changes that typically last for 10-100 ms, participate in the generation and maintenance of cortical rhythms. We show here that these fast events can have influences that outlast the duration of the synaptic potentials by interacting with subthreshold membrane potential oscillations. Inhibito...
Article
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Thalamic inputs strongly drive neurons in the primary visual cortex, even though these neurons constitute only ~5% of the synapses on layer 4 spiny stellate simple cells. We modeled the feedforward excitatory and inhibitory inputs to these cells based on in vivo recordings in cats, and we found that the reliability of spike transmission increased s...
Data
The phase shifts as a function of the phase of the subtreshold oscillation.
Article
The authors used connectionist modeling to extend previous research on emotion overgeneralization effects. Study 1 demonstrated that neutral expression male faces objectively resemble angry expressions more than female faces do, female faces objectively resemble surprise expressions more than male faces do, White faces objectively resemble angry ex...
Article
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Information geometry has been suggested to provide a powerful tool for analyzing multineuronal spike trains. Among several advantages of this approach, a significant property is the close link between information-geometric measures and neural network architectures. Previous modeling studies established that the first- and second-order information-g...
Article
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Visual scenes comprise enormous amounts of information from which nervous systems extract behaviorally relevant cues. In most model systems, little is known about the transformation of visual information as it occurs along visual pathways. We examined how visual information is transformed physiologically as it is communicated from the eye to higher...
Chapter
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Cortical cells belong to small interconnected ensembles. These ensembles have the potential of being activated in a reverberatory fashion in vitro and in vivo, spontaneously or in response to stimulation. We combined computer simulations and in vitro intracellular recording from prefrontal cortical neurons to explore the elicitation, modulation, an...
Chapter
During slow-wave sleep, cortical neurons oscillate between up and down states. Using a computational model of cortical neurons with realistic synaptic transmission, we determined that reverberation of activity in a small network of about 40 pyramidal cells could account for the properties of up states in vivo. We found that experimentally accessibl...
Article
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Animals use vision to perform such diverse behaviors as finding food, interacting socially with other animals, choosing a mate, and avoiding predators. These behaviors are complex and the visual system must process color, motion, and pattern cues efficiently so that animals can respond to relevant stimuli. The visual system achieves this by dividin...