Biology subjects

Barkai, E.

Publications and source records attributed to Barkai, E..

5 recordsLinked to original sources

bioRxiv2025

Epigenetic inheritance of complex learning abilities in the mammalian brain

For several decades, the question of whether cognitive and learning capacities can be inherited through non-genetic mechanisms has been the subject of ongoing debate. Here, we provide the first evidence of transgenerational inheritance of enhanced ability to learn complex tasks in the mammalian rodent brain. These inherited learning enhancements are not limited to specific stimuli, sensory modalities, or learning paradigms. Using behavioral, cellular biophysical, methylomics, genetics and molecular methods, we find that the inherited epigenetic modifications reflect an enhanced neuronal learning state, driven by increased intrinsic neuronal excitability in most pyramidal neurons in the relevant neuronal networks. This enhancement is mediated by persistent downregulation of the muscarinic M-current and is associated with widespread changes in DNA methylation, notably within coding genes associated with the M-current, the Kv7 pathway, in the hippocampi of trained F0 rats, as well as in non-coding RNAs in their sperm samples. Remarkably, a significant portion of these DNA methylation changes were also observed in the hippocampi of their untrained F1 offspring. These findings suggest that complex learning abilities can be inherited in the mammalian brain, as the offspring of trained rodents are born with the biophysical modifications that enable them to become super-learners, the exact change that occurs in their parents brains only after the rule learning.

neuroscience↗

bioRxiv2025

BIOPHYSICAL MECHANISMS UNDERLYING THE GENERATION AND MAINTENANCE OF RULE-LEARNING ENGRAM

Training rodents in a particularly difficult olfactory-discrimination task results with acquisition of high skill to perform the task superbly, termed rule-learning. We show that rule-learning occurs abruptly, in a "light bulb moment". Using whole-cell patch-clamp recordings in the piriform cortex of Fos2A-iCreER/TRAP2 mice, we targeted activated neurons, expressing immediate early genes (IEG). From the onset of training, IEG-positive neurons from trained animals display enhanced intrinsic excitability. Subsequently, synaptic excitation and inhibition is enhanced in these neurons, in a coordinated, cell-wide process. In parallel, the density of IEG-expressing neurons sharply declines. Double labeling with TRAP and c-Fos reveals that nearly two-thirds of the rule-memory engram neurons were engaged from the beginning of training. Silencing TRAP-expressing neurons using DREADDs leads to a complete loss of rule memory. We propose that rule learning occurs at a discrete moment, and is developed through a gradual process that stabilizes the memory of the rule.

neuroscience↗

bioRxiv2022

Neural activity and theta rhythmicity in the anterior hypothalamic nucleus are involved in regulating social investigation

Social interactions are highly complex, involving both approach and avoidance actions towards specific individuals, dependent on the social context. Currently, the brain regions subserving these behaviors are not fully known. The anterior hypothalamic nucleus (AHN) is a relatively unstudied and poorly defined brain area, known as part of the medial hypothalamic defensive system. Recent studies that examined the role of the AHN in various contexts have yielded contradicting results regarding its contribution to approach, avoidance, and escape behaviors. Yet, none of these studies has directly examined its role in social interactions. Here we explored the role of AHN neurons in regulating approach and avoidance actions towards distinct stimuli during various types of social interactions, using electrophysiological recording of neural activity in the AHN of behaving mice, c-Fos staining, and direct optogenetic stimulation. We found that theta rhythmicity in the AHN was enhanced during affiliative interactions, but decreased during aversive ones. Moreover, spiking activity of AHN neurons was found to be elevated more persistently during investigation of social stimuli, as compared to objects. Notably, AHN neuronal firing was found to be modulated by theta rhythmicity during social interactions. Finally, we found that during social interaction, direct optogenetic stimulation of AHN neurons augmented approach behavior towards stimuli associated with the optogenetic activation. Overall, our results suggest a context-dependent role for AHN neuronal activity in regulating approach behavior during social interactions, and for theta rhythmicity in mediating the valence of the social context.

neuroscience↗

bioRxiv2021

Plasticity of olfactory bulb inputs mediated by dendritic NMDA-spikes in piriform cortex

The piriform cortex (PCx) is essential for learning of odor information. The current view postulates odor learning in the PCx is mainly due to plasticity in intracortical (IC) synapses, while odor information from the olfactory bulb carried via the lateral olfactory tract (LOT) is "hardwired". Here we revisit this notion by studying location and pathway dependent plasticity rules. We find that in contrast to the prevailing view, synaptic and optogenetically activated LOT synapses undergo strong and robust long-term potentiation (LTP) mediated by only few local NMDA-spikes delivered at theta frequency, while global spike timing dependent plasticity protocols (STDP) failed to induce LTP in these distal synapses. An inverse result was observed for more proximal apical IC synapses; they undergo plasticity with STDP but are refractive to local NMDA-spike protocols. These results are consistent with a self-potentiating mechanism of odor information via NMDA-spikes which can form branch-specific memory traces of odors.

neuroscience↗

bioRxiv2018

NMDA spikes mediate amplification of odor pathway information in the piriform cortex

The piriform cortex (PCx) receives direct input from the olfactory bulb (OB) and is the brains main station for odor recognition and memory. The transformation of the odor code from OB to PCx is profound: mitral and tufted cells in olfactory glomeruli respond to individual odorant molecules, whereas pyramidal neurons (PNs) in the PCx responds to multiple, apparently random combinations of activated glomeruli. How these \"discontinuous\" receptive fields are formed from OB inputs remains unknown. Counter to the prevailing view that olfactory PNs sum their inputs passively, we show for the first time that NMDA spikes within individual dendrites can both amplify OB inputs and impose combination selectivity upon them, while their ability to compartmentalize voltage signals allows different dendrites to represent different odorant combinations. Thus, the 2-layer integrative behavior of olfactory PN dendrites provides a parsimonious account for the nonlinear remapping of the odor code from bulb to cortex.

neuroscience↗