Bruno Bontempi's research while affiliated with French National Centre for Scientific Research and other places

Publications (60)

Article
Full-text available
ATP signaling and surface P2X4 receptors are upregulated selectively in neurons and/or glia in various CNS disorders including anxiety, chronic pain, epilepsy, ischemia, and neurodegenerative diseases. However, the cell-specific functions of P2X4 in pathological contexts remain elusive. To elucidate P2X4 functions, we created a conditional transgen...
Article
Cognitive disabilities that occur with age represent a growing and expensive health problem. Age-associated memory deficits are observed across many species, but the underlying molecular mechanisms remain to be fully identified. Here, we report elevations in the levels and activity of the striatal-enriched phosphatase (STEP) in the hippocampus of a...
Article
Full-text available
Keywords: eight-arm radial maze false information observing errors social learning spatial reference memory Learning by observing others has been acknowledged as a powerful learning strategy. Whereas in several species observation of fear conditioning or other operational procedures can improve subsequent performance during actual learning, much le...
Article
Rats have the ability to learn about potential food sources by sampling their odors on the breath of conspecifics. Although this ethologically based social behavior has been transposed to the laboratory to probe nonspatial associative olfactory memory, only a few studies have taken full advantage of its unique features to examine the organization o...
Data
Acute tianeptine treatment selectively modulates neuronal activation in the central nucleus of the amygdala and attenuates fear extinction
Article
Full-text available
Post-learning hippocampal sharp wave-ripples (SWRs) generated during slow wave sleep are thought to play a crucial role in memory formation. While in Alzheimer’s disease, abnormal hippocampal oscillations have been reported, the functional contribution of SWRs to the typically observed spatial memory impairments remains unclear. These impairments h...
Article
Introduction: The cognitive consequences and the underlying mechanisms leading to cognitive impairments after cerebrovascular occlusive diseases are still unclear. Previously we have shown that distal middle cerebral artery occlusion (dMCAO) led to hippocampal hypofunction and spatial memory impairment in the absence of direct hippocampal injury. H...
Article
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Antidepressant drugs are commonly prescribed treatments for anxiety disorders, and there is growing interest in understanding how these drugs impact fear extinction because extinction learning is pivotal to successful exposure-based therapy (EBT). A key objective within this domain is understanding how antidepressants alter the activation of specif...
Data
Significant correlations were found between normalized Fos counts measured in the CA1 (A) or the CA3 (B) fields of the hippocampus and the DMS for all mice groups. (Black squares: Allocentric mice; Open squares: Sequential egocentric mice; Gray squares: Swimming control mice.) (PDF)
Data
Full-text available
Accelerating Rotarod performances. Performances on the accelerating rotarod were not significantly different for all mice groups. In particular, lesions did not affect motor performances on the rotarod test. (PDF)
Data
Examples of direct path score calculation for different trajectories. The direct path to the goal is represented by the sequence of three successive turns following the 1, 10, 8, 7 alleys. A turn score is given for each of the three intersections encountered along the direct path: intersection I (1;10), intersection II (10;8) and intersection III (...
Article
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We investigated the neural bases of navigation based on spatial or sequential egocentric representation during the completion of the starmaze, a complex goal-directed navigation task. In this maze, mice had to swim along a path composed of three choice points to find a hidden platform. As reported previously, this task can be solved by using two hi...
Data
Full-text available
The control group used to evaluate the nonspecific aspects of the training procedure on expression of the c-fos activity-dependent gene. Mice were allowed to swim in only one alley, corresponding to the departure alley of the experimental group, namely alley 1 during training trials and alley 5 during probe trials. Swimming occurred in the presence...
Article
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Understanding how brief synaptic events can lead to sustained changes in synaptic structure and strength is a necessary step in solving the rules governing learning and memory. Activation of ERK1/2 (extracellular signal regulated protein kinase 1/2) plays a key role in the control of functional and structural synaptic plasticity. One of the trigger...
Article
Full-text available
According to systems consolidation, as hippocampal-dependent memories mature over time, they become additionally (or exclusively) dependent on extra-hippocampal structures. We assessed the recruitment of hippocampal and cortical structures on remote memory retrieval in a performance-degradation resistant (PDR; no performance degradation with time)...
Article
Reduction in neuronal activity in remote brain regions after stroke is likely caused by a disruption of afferent excitatory input originating from distant infarcted areas. Environmentally induced neuroplasticity has been shown to be effective in reducing impairment in many experimental models of brain injury and neurodegeneration. The current study...
Article
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Although formation and stabilization of long-lasting associative memories are thought to require time-dependent coordinated hippocampal-cortical interactions, the underlying mechanisms remain unclear. Here, we present evidence that neurons in the rat cortex must undergo a “tagging process” upon encoding to ensure the progressive hippocampal-driven...
Article
Full-text available
Historically, the hippocampus has been viewed as a temporary memory structure. Consistent with the central premise of standard consolidation theory (SCT), a memory is initially hippocampus-dependent but, over time, it undergoes a consolidation process and eventually becoming represented in a distributed cortical network independent of the hippocamp...
Article
Although hippocampal-cortical interactions are crucial for the formation of enduring declarative memories, synaptic events that govern long-term memory storage remain mostly unclear. We present evidence that neuronal structural changes, i.e., dendritic spine growth, develop sequentially in the hippocampus and anterior cingulate cortex (aCC) during...
Conference Paper
In the adult brain, the dentate gyrus continuously produces new neurons that become functionally integrated into existing neural circuits. Supporting the idea that this form of plasticity contributes to memory functions, we recently found that new neurons are recruited into neuronal networks involved in retrieval of remote spatial memory and that t...
Article
Full-text available
The dentate gyrus (DG), a hippocampal subregion, continuously produces new neurons in the adult mammalian brain that become functionally integrated into existing neural circuits. To what extent this form of plasticity contributes to memory functions remains to be elucidated. Using mapping of activity-dependent gene expression, we visualized in mice...
Article
Full-text available
Memories are thought to be encoded by sparsely distributed groups of neurons. However, identifying the precise neurons supporting a given memory (the memory trace) has been a long-standing challenge. We have shown previously that lateral amygdala (LA) neurons with increased cyclic adenosine monophosphate response element–binding protein (CREB) are...
Article
Full-text available
Recent studies have shown that the anterior (ATN) and lateral thalamic nuclei (including the intralaminar nuclei; ILN/LT) play different roles in memory processes. These nuclei have prominent direct and indirect connections with the hippocampal system and/or the prefrontal cortex and may thus participate in the time-dependent reorganization of memo...
Article
Full-text available
Although gait changes are considered as reliable indices of stroke severity and efficacy of rehabilitative therapies in humans, data from animal models of focal ischemia are lacking. To determine the effect of stroke on gait function in adult rats with distal middle cerebral artery occlusion (MCAO), we assessed the longitudinal changes in gait usin...
Chapter
Both clinical studies and experiments in animals have provided evidence for the existence of a temporally graded retrograde amnesia following lesions of the medial temporal lobe, including the hippocampus. This form of amnesia, which is characterized by a loss of memory for recent events acquired prior to the onset of amnesia while more remote memo...
Article
The hippocampus and adjacent medial temporal lobe structures are known to support declarative memory, but there is not consensus about what memory functions the hippocampus might support that are distinct from the functions of the adjacent cortex. One idea is that the hippocampus is specifically important for allocentric spatial memory, e.g., the h...
Article
Studies of brain-damaged patients have provided remarkable insights into how our memories are organized (1). In particular, these studies have established that memory consolidation is a dynamic process involving gradual (but quite dramatic) reorganization of the circuits supporting memory over time (2, 3). A pioneer in this field was the French psy...
Article
A fundamental question in memory research is how our brains can form enduring memories. In humans, memories of everyday life depend initially on the medial temporal lobe system, including the hippocampus. As these memories mature, they are thought to become increasingly dependent on other brain regions such as the cortex. Little is understood about...
Article
The hippocampus is crucial for spatial memory formation, yet it does not store long-lasting memories. By combining functional brain imaging and region-specific neuronal inactivation in mice, we identified prefrontal and anterior cingulate cortices as critical for storage and retrieval of remote spatial memories [correction]. Imaging of activity-dep...
Article
Full-text available
Although the molecular, cellular, and systems mechanisms required for initial memory processing have been intensively investigated, those underlying permanent memory storage remain elusive. We present neuroanatomical, pharmacological, and genetic results demonstrating that the anterior cingulate cortex plays a critical role in remote memory for con...
Article
Full-text available
Several studies have demonstrated the importance of nicotinic mechanisms in the pathophysiology of neurodegenerative and cognitive disorders, warranting the search and development of novel nicotinic ligands as potential therapeutic agents. The present study was designed to assess whether the subtype-selective nicotinic acetylcholine receptor (nAChR...
Article
Pre-test exposure to training-related cues is known to improve subsequent retention performance. To identify brain regions engaged in processes promoted by retrieval cues, a brain imaging approach using the [6-14C]glucose autoradiographic technique was used. Sprague-Dawley rats trained in a brightness discrimination avoidance task were submitted to...
Article
Excitotoxic lesions of the nucleus basalis magnocellularis (nbm) in rats produce deficits in performance of the 5-choice serial reaction time (5CSRT) task, suggesting that basal forebrain cholinergic projections to the neocortex play an important role in visuospatial attention. However, non-selective damage induced by excitotoxins may have confound...
Article
Preclinical and clinical data have suggested the potential use of nicotinic acetylcholine receptor (nAChR) ligands for treating cognitive dysfunction associated with neurodegenerative diseases, such as Alzheimer's disease. SIB-1553A, (+/-)-4-[[2-(1-methyl-2-pyrrolidinyl)ethyl]thio]phenol hydrochloride, a novel nAChR ligand with predominant agonist...
Chapter
The purpose of this chapter is to introduce the reader to proper experimental procedures for the use of mice in learning and memory models. As the selection of appropriate learning and memory tasks requires knowledge of the cognitive processes modeled by these tasks, theoretical concepts will first be considered. The rest of the chapter describes t...
Article
Retrograde amnesia observed following hippocampal lesions in humans and animals is typically temporally graded, with recent memory being impaired while remote memories remain intact, indicating that the hippocampal formation has a time-limited role in memory storage. However, this claim remains controversial because studies involving hippocampal le...
Article
Neuronal nicotinic acetylcholine receptors (NAChRs) are pentameric ligand-gated ion channel receptors which exist as different functional subunit combinations which apparently subserve different physiological functions as indicated by molecular biological and pharmacological techniques. It is possible to design and synthesize novel compounds that h...
Article
Certaines formes de mémoire dépendent d'un système de structures du lobe temporal médian, incluant l'hippocampe, le cortex rhinal et le gyrus parahippocampique. Néanmoins, le rôle de ce système ne serait que temporaire, dans la mesure où son atteinte peut entraîner une amnésie rétrograde portant sur les souvenirs récents mais épargnant les souvenir...
Article
The present study analyses the effects of the stage of learning on the spatial patterns and time-course of [14C]glucose uptake in BALB/c mice brain regions produced by spatial discrimination training in an eight-arm radial maze. Our particular approach was designed to follow, during the post-training period, the level of functional activity in indi...
Article
The effects of chronic alcohol consumption on regional brain glucose metabolism were examined in Balb/c mice using the [14C]2-deoxyglucose autoradiographic technique. Animals were given a solution of 12% v/v ethanol as their only source of fluid for either 6, 12 or 18 months and compared to control groups receiving either an isocaloric solution or...
Article
S 9977 (1,3,7-trimethyl 8-[3-(4-diethylaminocarbonyl-l-piperazinyl)1-propyl]-3,7-dihydro(1H)2,6-purinedione hydrochloride) is a methylxanthine derivative lacking activity at adenosine receptors and having no phosphodiesterase inhibitory action, but which has been reported to enhance cholinergic function. In mice 0.06 mg/kg ip increased, whereas 0.2...
Chapter
This paper presents studies of the temporal development of memory traces in the brain using relative metabolic activity methodologies with (14C)-2-deoxyglucose (2-DG) to sample long time-frames (40 min) or (14C)-glucose to capture shorter-lived phenomena (5 min). During the early consolidation period, labelling increases were observed in subcortica...
Article
Previous results have suggested that memory processing may involve the sequential activation of subcortical and cortical structures. To study this phenomenon, we have examined the immediate (15 min) and delayed (220 min) metabolic changes produced in BALB/c mice by a partial training session in a bar-pressing appetitive task, using the [14C]-2-deox...
Article
Apamin, a neurotoxin extracted from bee venom, specifically binds to a particular class of Ca(2+)-activated K+ channels which are involved in the slow afterhyperpolarization (S-AHP) that follows action potentials in many excitable cells. We tested in mice the effects of apamin on learning and memory processes. The results showed that pre-training i...
Article
Regional mapping of relative (14C)-glucose (GLU) uptake was analyzed in Balb/c mice at 3 time intervals (5 min., 1 hr., 3 hrs.) after either the first (Day 1) or the last (Day 9) daily sessions of a spatial discrimination testing procedure in an eight-arm radial maze. On Day 1, increased labelling was found 5 min. post-training in subcortical, hipp...
Article
Although hippocampal-cortical interactions are crucial for the formation of enduring declarative memories, synaptic events that govern long-term memory storage remain largely unclear. We present evidence that structural remodelling of neurons, i.e. dendritic spine growth, develops sequentially in the hippocampus and anterior cingulate cortex during...

Citations

... In the dorsal horn of the spinal cord, the specific upregulation of P2X4 in the microglia has been shown of paramount importance for the development of pain hypersensitivity caused by nerve injury [34,43,47]. Using a conditional internalization-defective P2X4mCherryIN knock-in mice, we recently showed that the increase in P2X4 at the surface of excitatory neurons reduces anxiety, impairs memory processing and alters synaptic plasticity in the hippocampus [48]. In the context of ALS, P2X4 have been shown to be upregulated in microglia [46] and the MNs of mutant SOD1-G93A (SOD1) mice before their death [30]. ...
... The decreased MAPK activation is also reported to be involved in age-related memory decline in mice, rats, monkeys, and humans, and the striatal-enriched phosphatase (STEP) is found to be an important trigger (Castonguay et al., 2018). These findings suggest that gradual loss of MAPK-dependent memory protection mechanism might be conserved from Drosophila to humans. ...
... All studies we are aware of involving rats learning a goal location by observation alone involved previously explored spaces (Takano et al., 2017;Bem et al., 2018), or learned the strategy of the task rather than the location (Leggio et al., 2000Petrosini et al., 2003). Leggio demonstrated the role of the cerebellum in learning successful strategies from conspecific experience in various spatial tasks (Morris water mazes). ...
... It has been shown that STFP generates robust and long-lasting memories in rodents (Bessières et al., 2017;Clark et al., 2002;Galef et al., 1984;Galef and Whiskin, 2003). Clark and colleagues (2002) have shown that a single brief interaction between observer and demonstrator rats could still induce a food preference 3 months later. ...
... Alternatively, our results can be accounted by conceptualizing the plus maze (four options), T-maze (three options), and turn alternation (two options) tasks in terms of task difficulty due to different numbers of spatial options provided in these experimental settings (Jaffard, Bontempi, & Menzaghi, 2001;Smith et al., 2014). Under this framework, information processing capabilities of Artemia sp. ...
... With in vivo studies, fewer SWRs were found in APP/PS1 mice that overexpress human genes for amyloid precursor protein (APP) and presenilin1 (PS1) (Jura et al., 2019), and apoE4-KI mice that have the human AD genetic risk factor, Apolipoprotein (apo) E4, knocked in (Gillespie et al., 2016;Jones et al., 2019). Reduction in learning induced SWRs was also found in a mouse model injected with soluble amyloid beta oligomers solution (Nicole et al., 2016), as well as in both young and old rTg4510 mice overexpressing tau in the hippocampus (Booth et al., 2016;Ciupek et al., 2015;Witton et al., 2016). Along with learning-induced SWRs, slow gamma (20-50 Hz) power is elevated during SWRs in wild type animals (Carr et al., 2012). ...
... Previously we found that distal MCA occlusion produces mild impairment in spatial learning and memory (Wang et al. 2009b). Here we determined whether AAV-Netrin-1 gene therapy also improved post stroke cognitive function in the hippocampal dependent Barnes maze test. ...
... For example, a pronounced increase in excitatory postsynaptic potentials amplitude was measured in CA1 cells following operant conditioning of mice using the same paradigm as in the present experiment (Jaffard and Jeantet, 1981). The hippocampus CA1 metabolic activation during learning shown in the present study parallels hippocampus learninginduced increase in local cerebral glucose uptake described previously using the same behavioral task and the same training conditions (Sif et al., 1991;Destrade et al., 1992). ...
... There are major alterations in thalamocortical activation, with a marked reduction of the number of thalamic neurones projecting into the prefrontal cortex [11] and a reduced volume in the thalamus, which will lead to inappropriate activation of cortical areas and reduced blood flow in the prefrontal cortex. The hippocampal to ventromedial prefrontal cortex (H-PFC) pathway is now widely accepted to be a critical pathway in psychiatric disorders [7,[12][13][14] and crucial for cognition; hippocampal memories are laid down in the ventromedial PFC with time in man [15], and H-PFC coupling is impaired in schizophrenia [16,17]. Indeed, H-PFC and thalamic miscommunication is the reason for working memory deficits in schizophrenia [18]. ...
... Similarly, lesions to HPC (e.g., Hollup et al., 2001a;Morris et al., 1982;O'Keefe et al., 1975), as well as to DMS (e.g., Devan and White, 1999;Lee et al., 2014), render rats unable to flexibly use a place strategy to locate a hidden escape platform in the Morris water maze task. More recently, it was discovered that lesions to either HPC or DMS also impaired sequential-egocentric navigation in a starmaze task with multiple sequential decision points (Fouquet et al., 2013). One interpretation is that HPC is required for organizing not just spatial but also sequential event information, in line with the purported role of this structure in spatiotemporal relational memory processes (e.g., Eichenbaum, 2017). ...