Biology subjects

Marmor, O.

Publications and source records attributed to Marmor, O..

5 recordsLinked to original sources

bioRxiv2025

Brain-Wide Subnetworks within and between Naturally Socializing Typical and Autism Model Mice

Social interaction is inherently asymmetric, requiring coordinated activity between non-homologous brain regions across individuals. However, the brain-wide dynamics underlying such inter-brain coordination remain poorly understood. We used multi-fiber photometry to simultaneously record from 24 brain regions in pairs of freely interacting mice, including a model of autism. Social interactions evoked widespread, dynamic activity across brains, with inter-brain synchrony, especially between non-homologous areas, exceeding intra-brain synchrony, particularly in dominant mice. Network analysis revealed three subnetworks: (1) Emotional, intra-brain enhanced in subordinates; (2) Sensory, spanning both mice; (3) Decision/consolidation, linking dominant prefrontal cortex to subordinate hippocampus. These subnetworks encoded dominance, identity, and interaction roles, and followed a clear temporal sequence around social events. In an autism model, socially evoked activity was hyperactive displaying mostly within brain synchrony but lacked inter-brain synchrony. Our results uncover dynamic inter-brain circuits as a hallmark of social behavior and reveal their disruption in autism.

neuroscience↗

bioRxiv2025

'What' and 'where' brain-wide pathways are dominated by internal strategies

It is long thought that higher-order sensory processing is divided into two specialized cortical streams that encode in parallel either the identity of an object or its location (i.e., what and where streams). Here, using the mouse whisker system, we challenge this concept by demonstrating an existence of two alternating brain-wide (beyond cortex) subnetworks that are not primarily driven by external parameters, but rather by internal strategies. We combine simultaneous brain-wide neuronal recordings in mice trained to identify or locate a certain stimulus. We find that mice deploy either an active search or a passive sensation strategy during task performance. These strategies respectively drive two distinct and brain-wide subnetworks, frontal and posterior, regardless of the type of task performed. The posterior subnetwork encoded additional internal strategic parameters such as trial history, the first task of the day, and training history. A subgroup of trials that were not dominated by frontal cortex, contained meaningful task information in the posterior cortex and several thalamic areas. Integrated together, these two subnetworks may comprise normal cognitive function.

neuroscience↗

bioRxiv2022

History information emerges in the cortex during learning

We learn from our experience but the underlying neuronal mechanisms incorporating past information to facilitate learning is relatively unknown. Specifically, which cortical areas encode history-related information and how is this information modulated across learning? To study the relationship between history and learning, we continuously imaged cortex-wide calcium dynamics as mice learn to use their whiskers to discriminate between two different textures. We mainly focused on comparing the same trial type with different history information, i.e., a different preceding trial. We found history information in barrel cortex (BC) during stimulus presentation. Importantly, history information in BC emerged only as the mouse learned the task. Next, we also found learning-dependent history information in rostrolateral (RL) association cortex that emerges before stimulus presentation, preceding activity in BC. History information was also found in other cortical areas and was not related to differences in body movements. Interestingly, a binary classifier could discriminate history information at the single trial level just as well as current information both in BC and RL. These findings suggest that past experience emerges in the cortex around the time of learning, starting from higher-order association area RL and propagating down (i.e., top-down projection) to lower-order BC where it can be integrated with incoming sensory information. This integration between the past and present may facilitate learning.

neuroscience↗

bioRxiv2020

Frequency matters: Up- and Down-Regulation of Dopamine Tone Induces Similar Frequency Shifts in Cortico-Basal Ganglia Beta Oscillations

Beta oscillatory activity (13-30Hz) is pervasive within the cortico-basal ganglia (CBG) network. Studies in Parkinsons disease (PD) patients and animal models suggested that beta-power increases with dopamine depletion. However, the exact relationship between oscillatory power, frequency and dopamine-tone remains unclear. We recorded neural activity in the CBG network of non-human-primates (NHP) while acutely up- and down-modulating dopamine levels. Further, we assessed changes in beta oscillations of PD patients following acute and chronic changes in dopamine-tone. Beta oscillation frequency was strongly coupled with dopamine-tone in both NHPs and human patients. In contrast, power, coherence between single-units and LFP, and spike-LFP phase-locking were not systematically regulated by dopamine levels. These results demonstrate via causal manipulations that frequency, rather than other properties, is the key property of pathological oscillations in the CBG networks. These insights can lead to improvements in understanding of CBG physiology, PD progression tracking and patient care.

neuroscience↗

bioRxiv2018

Human Subthalamic Nucleus Selectively Decreases its Response to the Go-Signal in a Motor Inhibition Context

To better understand the mechanism of movement facilitation and inhibition in the subthalamic nucleus (STN), we recorded subthalamic multiunit activity intra-operatively while parkinsonian patients (n=43 patients, 173 sites) performed increasingly complex oddball paradigms: auditory ( None-Go, n=7, 28), simple movement ( All-Go, n=7, 26) and movement inhibition ( Go-NoGo, n=29, 119) tasks. To enable physiological sampling of the different subthalamic nucleus domains in both hemispheres, each patient performed one of the oddball paradigms several times.\n\nThe human STN responded mainly to movement-involving tasks: movement execution at the motor STN and movement planning at the limbic-associative STN. In the limbic-associative STN, responses to the inhibitory cue (deviant tone) in the movement inhibition task were not significantly different from the simple movement task. However, responses to the go cue (frequent tone) were significantly reduced. The reduction was mainly in the negative component of the evoked response amplitude. Successful movement inhibition was correlated with higher baseline activity before the inhibitory cue.\n\nWe suggest that the STN adapts to movement inhibition context by selectively decreasing the amplitude of neuronal activity. Thus, the STN enables movement inhibition not by increasing responses to the inhibitory cue but by reducing responses to the release cue. The negative component of the evoked response probably facilitates movement and a higher baseline activity enables successful inhibition of movement. These discharge modulations were found in the ventromedial, non-motor domain of the STN and therefore suggest a significant role of the associative-limbic domains in movement planning and in global movement regulation.

neuroscience↗