Recognition memory

Fast periodic visual stimulation (FPVS) has emerged as a promising tool for assessing cognitive function in individuals with dementia. This technique leverages electroencephalography (EEG) to measure brain responses to rapidly presented visual stimuli, offering a non-invasive and objective method for evaluating a range of cognitive functions. Unlike traditional cognitive assessments, FPVS does not rely on behavioural responses, making it particularly suitable for individuals with cognitive impairment. In this talk I will highlight a series of studies that have demonstrated its ability to detec

When you hear two versions of the same event, you can either update the memory of the first version with information from the second (updating) or retain both separately (differentiation). Prediction errors, the deviation between expected and actual outcomes, are presumably involved in mediating the competition between these processes. However, the mechanisms underlying this competition remain unclear. Here, we present a Hopfield network model that aims to account for the results of a behavioral study of memory updating. Participants heard conversational stimuli that were modified relative t

Background:Diet-induced inflammation, particularly from high-fat (HF) diet, is widely recognized as a contributing factor to neurological impairments and neurodegenerative disorders. Melanotan-II (MT-II), which targets and activates melanotropin receptors, may exert neuromodulatory and anti-inflammatory effects. Yet, the role of melanotropins in countering the diet-induced effects remain largely unexplored.Objective:The study investigates the possible relationship among diet, Melanotan-II (MT-II), a melanotropin receptor analog, and the behavior of zebrafish (Danio rerio).Methods:Zebrafish wer

In order to address the limited regenerative capacity of the mammalian brain and the challenges posed by aging-related neurological disorders, we harness reprogramming technology, focusing specifically on neural cell rejuvenation through transient expression of the 4 Yamanaka Factors (4Fs). As the brain ages and undergoes cognitive decline, homeostatic loss and neuroinflammation, our project focuses on the potential of partial reprogramming (PR) to reshape the epigenetic landscape, offering a promising avenue for cellular rejuvenation. We focus primarily on astrocytes, fundamental cells that c

…(BLA) reliably enhances declarative memory in humans after a one-day delay without eliciting an emotional response. In the current study 31 drug-resistant epilepsy patients undergoing stereo EEG surgery with depth electrode contacts implanted in various MLT regions. During continuous intracranial EEG recording, each participant was presented with a series of images of neutral objects. Across patients, we delivered a brief stimulation to the BLA (8 trains of 50-Hz pulses at 0.5 mA) before, during, or a

Abundant work has highlighted the functional role of the hippocampal formation in navigation behaviour across species. Recent studies highlight evidence that the same neural coding mechanisms found to underly the representation of physical spaces also apply to conceptual domains. Specifically, the representation of locations in both physical and conceptual spaces is reflected in distinct neural activity patterns in hippocampus and entorhinal cortex. Electrophysiological work from rodents has shown that single hippocampal place cells represent different locations in different spaces – a functio

…We employed the object recognition test to assess intermediate recognition memory. We used MK-801 (NMD

…in spatial and hippocampus-dependent memory abilities in rat models of Parkinson's disease (PD). Experiments were performed in adult male Wistar rats, including physiological controls(n=14) and toxin lesion-induced PD models: PD cholinopathy(n=10), hemiparkinsonism(n=7), and hemiparkinsonism with PD cholinopathy(n=6). Behavioral assessments and PV immunohistochemistry were performed 14 and 42 days after the lesions. Spatial and hippocampus-dependent short- and long-term memory were assessed with t

Consumption of cannabinoid-containing products has increased for their beneficial effects on pregnancy for reducing symptoms such as nausea, vomiting or anxiety. However, FDA clearly strongly advises against the use of delta-9-tetrahydrocannabinol (THC) during pregnancy. Alongside, mostly of the studies have investigated the effects of prenatal THC (pTHC) exposure, in males only, but pTHC shows a sex bias. Here, we investigate the effects of pTHC exposure in the male and female young rats.Sprague and Dawley rats were subcutaneously treated with THC (2 mg/kg/day) or vehicle (VHC), from gestatio

…early decline in episodic and spatial memory, associated with accumulation of brain markers. Intriguingly, despite similar levels of brain alteration, some elderly subjects show less cognitive impairment than others. To explain this lack of correlation between the degree of brain lesions and the severity of cognitive symptoms, the concept of cognitive resilience (CR) has emerged. Yet, the protective mechanisms supporting CR remain poorly understood. To tackle this issue, we developed a preclinical model of

…beta-amyloid depositions and memory alterations. Since hNGFp only acts on Tropomyosin receptor kinase A (TrkA), and non-cholinergic neurons do no

The noradrenergic (NA) system plays a critical role in memory consolidation, including declarative memory. Recognition memory, an important aspect of declarative memory, involves the ability to acquire and recall information to identify familiar stimulus. Novel Object Recognition (NOR) is a widely used task to assess this type of memory in rodents. This test is based on the innate preference for novelty and the ability to discriminate novel and familiar objects. Post-training yohimbine administration, an a2-adrenoceptor antagonist, enhances object location memory in mice, suggesting that incre

…which information is retained in memory. However, memory is not only affected by the amount of time spent viewing a visual scene but also by specific gaze patterns during visual exploration. Revisitations occur when the eye gaze returns to a previously fixated location, resembling retrieval processes and offering another chance to encode. What remains unclear is whether revisitations actually enhance long-term memory formation and how they are associated with hippocampal activity dynamics. In this study, 50 human participant

Sorting Nexin 27 (SNX27) is a hippocampal-enriched endosome-associated cargo adaptor that shapes endocytic events underlying neuronal function and excitability, being relevant for cognitive and reward-associated processes. There is an association of SNX27 with glutamatergic and dopaminergic signaling, as SNX27 modulation alters hippocampal glutamatergic transmission and dopaminergic neurons GABABR-activated GIRK signaling. Notwithstanding, the impact of SNX27 modulation on neuronal circuitry function or behavior remains elusive. In this work we deleted SNX27 in different neuronal types in orde

The connection between the right and left hippocampi is implicated in recognition memory. Demyelination in the hippocampal formation and fornix is an early event in Alzheimer's disease (AD). Preliminary studies from our group have shown demyelination in the hippocampal commissure both in animal models and in magnetic resonance imaging of AD patients, which could lead to abnormal oscillatory coupling between both hippocampi and diminished interhemispheric connectivity between the temporal lobes. Our objective was to analyze whether AD patients show alterations in oscillatory coupling between th

Schizophrenia (SCZ) is a frequent psychosis related to combination between genetic and environmental factors. To advance current treatments, it is important to improve animal models by considering its multifactorial etiology. Our study aimed to characterize an innovative 2-hit mouse model combining the deletion of serine racemase (genetic factor) associated with a maternal separation for 24h at post-natal day 9 (early stressing environmental factor), which both have been previously suggested to possibly drive SCZ-like symptoms. The face facility of this 2-hit model was assessed through behavio

…cognitive functions including semantic memory, recognition memory, attention and visual function. We have shown that Fastball is sensitive to cognitive dysfunction in Alzheimer’s disease and Mild Cognitive Impairment, with data collected in patients’ homes using low-cost portable EEG. We are n

It has long been established that the hippocampus plays a crucial role for episodic memory. As opposed to the modular approach, now it is generally assumed that being a complex structure, the HC performs multiplex interconnected functions, whose hierarchical organization provides basis for the higher cognitive functions such as semantics-based encoding and retrieval. However, the «where, when and how» properties of distinct memory aspects within and outside the HC are still under debate. Here we used a visual associative memory task as a probe to test the hypothesis about the differential invo

The successful recognition of familiar persons is critical for social interactions. Despite extensive research on the neural representations of familiar faces, we know little about how such representations unfold as someone becomes familiar. In three EEG experiments, we elucidated how representations of face familiarity and identity emerge from different qualities of familiarization: brief perceptual exposure (Experiment 1), extensive media familiarization (Experiment 2) and real-life personal familiarization (Experiment 3). Time-resolved representational similarity analysis revealed that fami