Spatial memory

What circuit mechanisms underlie the encoding and retrieval of spatial memory? In standard models, neurons have discrete fields that map onto locations, which are associated with actions [1]. Given that spatial-memory regions (such as hippocampus and entorhinal cortex) have recurrent architectures, it is unclear if this feedforward association mechanism is the only way in which spatial memories can be stored. Here, we propose a new mechanism for spatial memory that is derived from reverse-engineering recurrent neural networks (RNNs). We train RNNs on a spatial navigation task posed as a rein

Small vessel disease is characterized by stochastic occlusions of small vessels in the brain microvasculature. This results in impaired blood flow, increased blood-brain barrier permeability and neuronal cell death. While small vessel disease is the leading cause of vascular dementia, the underlying mechanisms remain elusive, limiting treatment options. Visual stimulation at specific frequencies can enhance neuronal activity, leading to remodelling of the cerebrovascular architecture. Specifically, evoked gamma oscillations through stimulation at 40Hz has been shown to rescue motor and cogniti

The present study was designed to evaluate age-related alterations of spatial memory in rats prenatally exposed to valproic acid (VPA). To induce autism-like animal model, the pregnant rats were intraperitoneally injected 500 mg/kg NaVPA at the gestation day 12.5. Experiments were carried out on three age groups of control and VPA-treated male offspring: prepubertal adolescence (postnatal day 30); adult (6 months) and old (22 months). Spatial memory and learning process was assessed in the Morris water maze (MWM). The effect of treatment on the learning process were analyzed by Two Way Repeate

…of executive functions and memory. Its primary pathophysiological hallmarks are amyloid plaques and neurofibrillary tangles. Promising humanised knock-in AD mouse models have been developed that exhibit Aβ pathology, neuroinflammation, synaptic dysfunction, and behavioural impairment. A rigorous battery of behavioural tests and analyses was utilised to further our knowledge of Alzheimer's disease.Our study comprised young (6-months), middle-aged (12-months), and old (22-months) AppNL-G-F

The rodent hippocampus is essential for spatial memory formation and navigation. Cognitive maps of each environment are created by a population of hippocampal pyramidal cells (PCs), some of which display spatially tuned firing (place cells). When an animal enters a novel environment, new spatially tuned firing (place fields: PFs) of PCs emerges. Place field formation in CA1 PCs has been proposed to rely on a well-established cellular mechanism called behavioural timescale synaptic plasticity (BTSP). During BTSP, a single occurrence of a long postsynaptic dendritic plateau potential and resulti

Disturbances to neuronal function at the level of the synapse are crucial features of neuropsychiatric disorders, such as schizophrenia. Synaptic dysfunction in the prefrontal cortex, and its consequences on neuronal circuitry and behaviour, have been extensively linked to the disease. In this study, we are characterising the functional and behavioural consequences of a recently discovered, schizophrenia-associated variant in the CACNG2 gene, coding for the postsynaptic protein stargazin (StgSCZ). The aim of our study is to uncover how dysfunction at the level of the synapse in the prefrontal

…dynamics underlying retrieval of spatial representations?We study the dynamics of recur

Spatial orientation deficits are emerging as very early and reliable cognitive biomarkers predicting future memory problems associated with Alzheimer’s disease, but the neural mechanisms underlying spatial disorientation have yet to be fully defined. The anterodorsal thalamic nucleus (ADn) contains a high density of head direction (HD) cells, which play a critical role in the brain's ability to create and update spatial representations, aiding in navigation and spatial memory. We propose that the accumulation of Tau filaments in cell bodies, dendrites, and axons of HD cells disrupts the proces

…and lasting reorganization of spatial representations in the CA1 area of the dorsal hippocampus. Such reorganization is absent when learning associations between rewards and non-spatial cues, for which spatial memory is not involved. Thus, the rodent brain selectively adjusts weights of hippocampal inputs, plasticity processes, and the stability of spatial representations, supporting adaptive be

Radiotherapy (RT) is the mainstay of brain cancer treatment due the generation of reactive oxygen species that cause double- and single-stranded DNA breaks. Although tumour cells are more radiosensitive, healthy cells are also subject to radiation damage, and as such therapeutic radiation can induce progressive cognitive decline. We investigated whether radiation-induced cognitive impairments could be prevented with the antioxidant tempol. Male C57BL/6 mice aged 27 weeks were administered either tempol (100mg/kg/day) or 0.9% saline for seven consecutive days via the I.P. route. One day after t

Programmed cell death (PCD) is essential for regulating cell homeostasis in the developing brain. Cell populations that undergo massive PCD in the cortex include the first wave of oligodendrocyte precursor cells (firstOPCs) and most of GABAergic interneurons, which die postnatally within the same period. Furthermore, firstOPCs and most interneurons share common embryonic origins. Here we investigated how PCD of both firstOPCs and their lineage-related interneurons impact behavior and cortical networks. We used behavioral assays, patch-clamp recordings and immunostainings in two mouse models in

Nutrient composition in obesogenic diets may influence the severity of disorders associated with obesity such as insulin-resistance and chronic inflammation. Here we hypothesized that obesogenic diets rich in fat and varying in fatty acid composition, particularly in omega 6 (ω6) to omega 3 (ω3) ratio, have various effects on energy metabolism, neuroinflammation and behavior. Mice were fed either a control diet or a high fat diet (HFD) containing either low (LO), medium (ME) or high (HI) ω6/ω3 ratio. Mice from the HFD-LO group consumed less calories and exhibited less body weight gain compared

…which plays a vital role in spatial memory processing. Spatial memory processing ability continues to develop alongside hippocampal maturation particularly before puberty. The N-methyl-d-aspartate (NMDA) type of glutamate receptor channel is essential for activity

Sex and age play significant roles in spatial and contextual memory formation; however, these factors are understudied especially considering the ongoing maturation of prefrontal cortex and hippocampus through juvenility until adulthood. The receptor of Oxytocin (OXTR) has sex-dimorphic characteristics and is expressed in these regions. We previously demonstrated that blockade of prefrontal OXTR impaired extinction of contextual fear memory in juvenile females but not males (Maroun 2020). The hippocampus is central to spatial memory formation and performance in spatial memory tasks is age and

…cells in CA1 from the acquisition of a spatial memory, through an extended rest period (~20 hours) to its recall. We applied multiple decoding strategies to track the evolution of memory related activity over several hours of sleep.We observed that while durin

…extensively researched; learning and memory have not studies. Moreover, the consequences connected to gender are not clearly discussed. You therefore made the decision to contrast and investigate spatial memory in male and female rats.In the present study, we assessed the short

…types of epileptiform activity, spatial learning and anxiety, and synaptic plasticity.We used th

…(depression, anxiety, pain) and memory (learning, retrieval, extinction). The project u

A major challenge in studying spatial memory is understanding whether and how different navigational strategies influence hippocampal spatial representations of the environment.We designed a spatial recency memory task with two variants: one requiring allocentric representations of location, the other entailing egocentric representations. 10 freely-moving rats were trained over 34 daily sessions; each day, rats learned and then recalled the position of a food reward among six locations. Each trial, animals entered the arena from one of four start locations, generating distinct origin-goal traj

…usage of enacted strategies in working memory contexts allows us to achieve better results. Here it has been investigated whether animals are also able to support their working memory with behavioral strategies or show working memory processes in their behavior. Pigeons were tested in Skinner boxes and presented with various stimuli on a key located in the center that had to be answered with one of two choices. In

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

…and replaying sequences of relevant spatial information. Previous studies on spatial memory adopted “cartography” paradigms in which subjects, typically moving in 2D, could remember and then rely on salient cues, such as landmarks or orientation cues. Little is known about navigation in curved environments with minimal salient information. The present project investigates such a capacity in a sparse, spheric, three-dimensional virtual reality environment that lacks salient landmarks and orientation cues. This

…late long-term potentiation, memory formation and cognition [1,2]. Four patients have been identified with a de-novo mutation c.928A>G in the CaMK4 gene (S. McLean, unpublished data), resulting in a M310V variant in the autoinhibitory domain of CaMK4. Clinically, these patients display developmental delays and intellectual disabilities, in some cases accompa

…astrocytes could mitigate AD-related memory deficits, neuropathology and neuroinflammation.We have generated two, acute and chronic, AD mouse models with astrocytic CaNB1 deletion (ACN-KO). In the acute one we evaluated the ability of β-amyloid oligomers (AβO