Mor Nitzan

Harvard University | Harvard

In mental time travel (MTT) one is “traveling” back-and-forth in time, remembering and imagining events. Despite intensive research regarding memory processes in the hippocampus, it was only recently shown that the hippocampus plays an essential role in encoding the temporal order of events remembered, and therefore plays an important role in MTT....

Depth electrodes locations in the hippocampus and lateral temporal cortex (LTC), shown on individual patients' MRI scans.

Electrophysiological results for the space-task in the right hemisphere. iEPs recorded at electrodes in the right LTC and right hippocampus. No clear distinction in task modulation is apparent between LTC electrodes and electrodes in the hippocampus. Shaded areas show time points of significant differences between conditions in two-tailed independe...

Electrophysiological results for the time-task in the right hemisphere. iEPs recorded at electrodes in the right LTC and right hippocampus. No clear distinction in task modulation is apparent between LTC electrodes and electrodes in the hippocampus. Shaded areas show time points of significant differences between conditions in two-tailed independen...

Electrophysiological results for the space-task in the left hemisphere. iEPs from all electrodes used in the classification analysis are presented. No clear distinction in task modulation is apparent between LTC electrodes and electrodes in the hippocampus. Shaded areas show time points of significant differences between conditions in two-tailed in...

The effect of reducing the number of electrodes used in the classification analysis. The distribution of cross-validation accuracy and corresponding p-values in the classification analysis of the MTT task, for subsets of 8 electrodes in the left hemispheres. Each subsets includes exactly 5 hippocampal electrodes and 3 lateral temporal electrodes, a...

Demonstration of iEPs polarity-reversal in the electrodes shown in Figure 1. Some iEPs in Figure 1 are of seemingly opposite polarity between Patients. This is the result of “polarity reversal” (Halgren et al., 1982). When recording iEPs from local generators, the polarity of the resulting iEP reverses as one records from two opposite sides of this...

Own-body transformation task: Participants viewed a schematic human figure with one hand marked, facing either toward them or away from them. In the ‘here’ condition participants were asked to judge from their own self-location whether the marked hand was on the right or the left side of the computer screen. In the ‘there’ condition, participants w...

Electrophysiological results for the time-task in the left hemisphere. Intracranial evoked potentials (iEPs) from all electrodes used in the classification analysis are presented. LTC electrodes (up) show high early task modulation, whereas electrodes in the hippocampus (bottom) show high late task modulation. Shaded areas show time points of signi...

Early and late modulation in time task, left hemisphere.

The topology of interactions in network dynamical systems fundamentally underlies their function. Accelerating technological progress creates massively available data about collective nonlinear dynamics in physical, biological, and technological systems. Detecting direct interaction patterns from those dynamics still constitutes a major open proble...

Level-1 consensus is a recently-introduced property of a preference-profile. Intuitively, it means that there exists a preference relation which induces an ordering of all other preferences such that frequent preferences are those that are more similar to it. This is a desirable property, since it enhances the stability of social choice by guarante...

Investigation of the functional macro-scale organization of the human cortex is fundamental in modern neuroscience. Although numerous studies have identified networks of interacting functional modules in the gray-matter, limited research was directed to the functional organization of the white-matter. Recent studies have demonstrated that the white...

Small RNAs (sRNAs) are central regulators of gene expression in bacteria, controlling target genes posttranscriptionally by base pairing with their mRNAs. sRNAs are involved in many cellular processes and have unique regulatory characteristics. In this review, we discuss the properties of regulation by sRNAs and how it differs from and combines wit...

Level-1 consensus is a property of a preference profile. Intuitively, it means that there exists some preference relation such that, when ordering the other preference-relations by increasing distance from it, the closer preferences are more frequent in the profile. This is a desirable property, since it enhances the stability of the social choice...

Revealing physical interactions in complex systems from observed collective dynamics constitutes a fundamental inverse problem in science. Current reconstruction methods require access to a system’s model or dynamical data at a level of detail often not available. We exploit changes in invariant measures, in particular distributions of sampled stat...

We present analytical results for the distribution of shortest path lengths between random pairs of nodes in configuration model networks. The results, which are based on recursion equations, are shown to be in good agreement with numerical simulations for networks with degenerate, binomial and power-law degree distributions. The mean, mode and var...

Infection and diffusion processes over networks arise in many domains. These introduce many challenging prediction tasks, such as influence estimation, trend prediction, and epidemic source localization. The standard approach to such problems is generative: assume an underlying infection model, learn its parameters, and infer the required output. I...

Mixed feedback loops combining transcriptional and post-transcriptional regulations are common in cellular regulatory networks. They consist of two genes, encoding a transcription factor and a small non-coding RNA (sRNA), which mutually regulate each other's expression. We present a theoretical and numerical study of coherent mixed feedback loops o...

Ndd1 activates the Mcm1-Fkh2 transcription factor to transcribe mitotic regulators. The anaphase-promoting complex/cyclosome activated by Cdh1 (APC/C(Cdh1)) mediates the degradation of proteins throughout G1. Here we show that the APC/C(Cdh1) ubiquitinates Ndd1 and mediates its degradation, and that APC/C(Cdh1) activity suppresses accumulation of N...

We present two complementary analytical approaches for calculating the distribution of shortest path lengths in Erdos-R\'enyi networks, based on recursion equations for the shells around a reference node and for the paths originating from it. The results are in agreement with numerical simulations for a broad range of network sizes and connectiviti...

The human microbiome is dynamic and unique to each individual, and its role is being increasingly recognized in healthy physiology and in disease, including gastrointestinal and neuropsychiatric disorders. Therefore, characterizing the human microbiome and the factors that shape its bacterial population, how they are related to host-specific attrib...

Cells adapt to environmental changes by efficiently adjusting gene expression programs. Staphylococcus aureus, an opportunistic pathogenic bacterium, switches between defensive and offensive modes in response to quorum sensing signal. We identified and studied the structural characteristics and dynamic properties of the core regulatory circuit gove...

Competing endogenous RNAs (ceRNAs) were recently introduced as RNA transcripts that affect each other’s expression level through competition for their microRNA (miRNA) coregulators. This stems from the bidirectional effects between miRNAs and their target RNAs, where a change in the expression level of one target affects the level of the miRNA regu...

Objective: Transient global amnesia (TGA), an abrupt occurrence of severe anterograde episodic amnesia accompanied by repetitive questioning, has been known for more than 50 years. Despite extensive research, there is no clear evidence for the underlying pathophysiological basis of TGA. Moreover, there is no neuroimaging method to evaluate TGA in...

Small RNAs are integral regulators of bacterial gene expression, the majority of which act posttranscriptionally by basepairing with target mRNAs, altering translation or mRNA stability. 6S RNA, however, is a small RNA that is a transcriptional regulator, acting by binding directly to σ(70)-RNA polymerase (σ(70)-RNAP) and preventing its binding to...

Supplemental methods. Also contains Tables S1 to S3.

Unlabelled: Type III secretion systems (TTSSs) are employed by pathogens to translocate host cells with effector proteins, which are crucial for virulence. The dynamics of effector translocation, behavior of the translocating bacteria, translocation temporal order, and relative amounts of each of the translocated effectors are all poorly character...

Enteropathogenic Escherichia coli (EPEC) is an important human pathogen that causes acute infantile diarrhea. The type IV bundle-forming pili (BFP) of typical EPEC strains are dynamic fibrillar organelles that can extend out and retract into the bacterium. The bfpF gene encodes for BfpF, a protein that promotes pili retraction. The BFP are involved...