Learning and memory

This meeting connects neural plasticity across molecular, synaptic, circuit and behavioural scales. The programme examines learning and memory, stress and threat responses, brain-body interactions, medial prefrontal function and behavioural strategies for interpreting neural dynamics. Additional sessions explore hippocampal computation, orbitofrontal contributions to learning and decisions, endogenous opioids, retrosplenial cortex, and activity-dependent plasticity in sensory pathways. Morning and evening symposia leave time for informal scientific discussion. Attendance is capped below 100. R

…plasticity, information processing and adaptive neural circuits. This role leads computational work on sleep within a multiscale CREST BioDX collaboration with Kaoru Inokuchi and Tatsuya Haga. Analytical approaches draw on statistical physics and information theory, alongside mathematical models of learning and memory. The postdoctoral category is for researchers within five years of their doctorate; the research-scientist category is for more experienced doctorate holders. The appointment is at RIKEN’s Wako campus, with annual renewal

The hippocampus is a key player in learning and memory. However, the microcircuit logic that endows the hippocampus with these capabilities remains virtually unknown. Hippocampal neurons exhibit tremendous diversity in terms of their gene expression, connectivity, and intrinsic properties. Recent work suggests that this diversity is rooted in the temporal progression of embryonic development, with neurons born at the same gestational timepoint exhibiting shared input and output connectivity, as well as correlated activity in-vivo. In this work, we combined embryonic birthdating of CA3-CA1 neur

To understand the neural basis of many cognitive processes, such as learning and memory, we need to track the millisecond, single-spike activity of neurons across days. However, compared to calcium imaging methods, tracking neurons in chronic electrophysiological recordings remains challenging. Recent studies have designed algorithms to do so, but mostly rely on engineered parameters that may not take advantages of the full complexity of the neuron’s electrophysiological waveform and miss or falsely match neurons. To go beyond these limitations, we developed DeepMatch, a deep neural network fr

Activity dependent synaptic plasticity is widely believed to play the major role in learning and memory. Moreover, the robustness of formed memories is dependent on the stability of synapses. However, recent studies have shown that synapses undergo a significant volatility which are activity independent [1]. This stochastic turnover therefore can put a great challenge on encoding and preserving information in synaptic connectivity [2]. In this study, using in vivo STED nanoscopy, morphological features of excitatory spines in mouse cortical circuits including head size, neck length, and neck w

Synaptic plasticity is thought to underlie learning and memory [1]. Plasticity rules can be active in different synaptic connection types, such as excitatory-excitatory (EE) and inhibitory-excitatory (IE) connections, with in silico and experimental evidence suggesting distinct mechanisms for each type [2,3,4]. While the interaction between connection types in learning and memory is an active research focus [5], studies typically probe only one type of plasticity at a time. Thus, at scale, the contributions of connection types and their co-active plasticity rules to memory processes remain unc

Astrocytes play a crucial role in regulating synaptic strength and orchestrating synaptic plasticity, which is fundamental for learning and memory. However, the specific mechanisms by which astrocytes and their neuroactive transmitters, like D-serine, control these processes remain largely unexplored. D-serine, a co-agonist for the NMDA receptor, has garnered increasing interest as a potential regulatory molecule in synaptic plasticity. Given its activity-dependent release mediated by astrocytes, D-serine is a key player in balancing long-term synaptic depression (LTD) and potentiation (LTP) d

…They are critical for grouping and selecting neuronal ensembles in the context of spatial navigation, memory, and learning, but the reason why this frequency band is particularly effective for adjusting neuronal ensembles remains speculative. Here we show that burst activity at the CA3-CA1 synapse of the mouse hippocampus leads to a rapid activation of astrocytic leaflets possibly via the retrograde release of endocannabinoids that activate transient receptor potential chann

Activity-dependent synaptic plasticity is widely believed to play the major role in learning and memory. Moreover, the robustness of memories depends on the stability of synapses. Recent studies, however, have shown that synapses exhibit significant volatility which to some extent appears activity-independent [1]. This stochastic turnover therefore can put a challenge on encoding and preserving information in synaptic connectivity [2]. In this study, using in vivo STED nanoscopy, to assess the dynamics of morphological features of excitatory spines in mouse cortical circuits including the dyn

The present study evaluated the effect of caffeic acid (CA) on behavioral learning and memory tasks in the diabetic state. We also evaluated the effect of this phenolic acid on the enzymatic activities of acetylcholinesterase, ecto-nucleoside triphosphate diphosphohydrolase, ecto-5-nucleotidase and adenosine deaminase as well as on the density of M1R, α7nAChR, P2X7R, A1R, A2AR, and inflammatory parameters in the cortex and hippocampus of diabetic rats. Diabetes was induced by a single intraperitoneal dose of streptozotocin (55 mg/kg). The animals were divided into six groups: control/vehicle;

Learning and memory processes activate a specific ensemble of neurons distributed across different brain regions, the so-called engram, inducing in them lasting physical and chemical changes. The allocation of neurons to the engram depends on their relative excitability. Therefore, mechanisms regulating the balance between excitation (E) and inhibition (I) in the brain influence memory formation. Nogo-A negatively regulates neuronal plasticity and influences the E/I balance by promoting inhibitory, while suppressing excitatory synaptic transmission. Moreover, loss of function for Nogo-A result

Epileptiform activity (EA) comprises abnormal excessive neuronal discharges (spikes and sharp waves) detectable by electroencephalogram. The term EA originates from epilepsy research, where interictal EA appears in EEG between seizures. Importantly, EA occurs not only in epilepsy but also in various pathologies, possibly contributing to cognitive impairment. EA has been observed in neurodegenerative disorders like Alzheimer's and Parkinson's diseases. However, a direct causal link between EA and cognitive impairment remains elusive. A significant issue is the lack of a pure EA model for invest

…the difference between the predicted and the received reinforcement serves as a driving force in the learning process to optimize future reinforcement prediction and to enable anticipatory approach or avoidance behavior. In the fruit fly brain, dopaminergic neurons in the mushroom body, a central structure for learning and memory, have been suggested to compute such

Establishing, maintaining and dynamically modifying synaptic connections is a key principle of neuronal computations. The underlying molecular resource of these processes is synaptic proteins. Tight control of protein levels across neurons is crucial to ensure synaptic function. Changes in the synaptic proteome have been associated with compromised synaptic function and in severe cases various diseases. Among the major factors in regulating protein levels are thought to be protein synthesis, trafficking and degradation. While there is substantial literature on protein synthesis, both trafficki

…basic mechanism underlying addiction and results in cognition deficiencies.In this work, we focused on the influence of MA on the development of the HP during postnatal days

…a risk factor for neurodevelopmental and psychiatric disorders. The major effector molecules of stress are glucocorticoids (GCs), which by binding to glucocorticoid receptors (GRs) regulate several biological processes in the brain and the body. So far, little is known about the effects of ELA on a subtype of glial cells, named oligodendrocyte precursor cells (OPCs) or NG2-glia. To investigate how GCs can affect the molecular signature of the NG2-glia and impact the behavioral phenotyp

Tone discrimination is a behavioral task to investigate learning and memory processes in rodents. Additional punishment (aP) can be applied to enhance discrimination abilities; however, some animals have difficulties learning the task with aP. To understand this effect, we conducted auditory fMRI in Mongolian gerbils throughout discrimination training with rising (GO) and falling (noGo) frequency-modulated (FM) tones in ten daily sessions (S), enforced through foot shocks for “Miss”; a second group additionally received aP for “False‑Alarm”. Gerbils of each training group were divided into “go

Learning and memory formation require activity-dependent rearrangements of neuronal networks driven by structural plasticity. The brain's perineuronal extracellular matrix (ECM), composed mainly of chondroitin sulfate proteoglycans from the lectican family, suppresses structural plasticity in the mature brain. Several members of this family, such as aggrecan and brevican, undergo proteolytic cleavage by proteases from the ADAMTS family, which may loosen the ECM structure. Therefore, we hypothesize that activity-dependent extracellular proteolysis weakens the ECM, supporting neuronal plasticity

How changes in synaptic connections underlie learning and memory is a central question in Neuroscience. Previous modeling efforts focused on biologically realistic learning rules and dynamics, but these rules usually produce bimodal weight distributions that are not aligned with experimentally observed lognormal distributions of synaptic weights. How biological learning rules preserve such unimodal distributions and at the same time retain information, i.e., learn, remains unknown. Here, we take a game-theoretical approach, asking whether learning is possible under the constraint of retaining

The oxidative stress and inflammation provoked by hypoxia can lead to damage to neurons in the hippocampus, a structure that plays a key role in learning and memory processes. Prevention of hypoxia-related damages may be achieved through different means: pharmacologically or behaviorally. Some plants have strong antioxidants properties, such as Guiera senegalensis (GS). Alternatively, performance of free-divers, without memory loss, suggests neuroprotective effects of extended training to apnea. We developed a rat model of hypoxia under voluntary apnea. Training consists of 3 to 4 weeks of hab

…for their integral role in shaping learning and memory. This study delves into the orchestration of these processes by FS BCs, particularly their involvement in controlling hippocampal high-frequency gamma oscillations (80-200 Hz) coupled with theta oscillatory activity (3-10 Hz). While existing research predominantly explores the connectivity of these neurons during memory-related rhythms, our investigation highlights an additional layer of subcellular complexity. Recent modeling and experimental findings reveal that FS

…between retaining older information and facilitating new learning. Dendritic spines, where excitatory synapses are located, represent the basic structural and functional unit of learning and memory at the neuronal level; spines are formed and/or modified during learning to support behavioral demands. However, how the interplay between plasticity and stability in dendritic spines is implemented to accommodate adaptations in behavior remains unclear. We investigated this question in head-fixed mice performing a rule-switch beh

Synaptic plasticity is the cornerstone of learning and memory. However, the mechanistic link between individual synaptic changes and emerging network functions remains elusive. Here, we apply a numerical method for meta-learning plasticity rules---filter Simulation-Based Inference (fSBI)---to in vivo data. We identify thousands of co-active excitatory(E)-to-E, E-to-inhibitory(I), I-to-E and I-to-I rules that can drive learning and memory functions in large recurrent spiking networks. We begin with large search spaces of flexibly-parameterized co-active plasticity rules. We then use fSBI to fil

…reduced in aged hippocampal neurons, and that restoring autophagy levels is sufficient to improve age-related memory impairment. Nonetheless, the regulatory mechanisms involved in neuronal autophagy decline during aging remain largely unknown. Exploring this question, we found that WD repeat domain phosphoinositide-interacting protein 2 (WIPI2), an important driver of auto