Biology subjects

Rozenfeld, E.

Publications and source records attributed to Rozenfeld, E..

4 recordsLinked to original sources

bioRxiv2026

Hypothalamic Representation of Aggressiveness across Mouse Strains

Aggression is an innate behavior conserved across species, serving as a critical means to compete for food, mating opportunities, and other essential resources. A central question in aggression research is the extent to which inter-individual variability in aggression is shaped by genetic factors. Here, we examine aggressive behaviors in naive male mice across seven genetically defined strains and find large cross-strain differences. We find a tight correlation between aggressiveness and anxiety levels across strains, but not within the same strain, suggesting strong genetic control of both traits. Pharmacologically elevating anxiety in high-aggression strains reduces aggression, revealing a causal relationship between these behaviors. We further demonstrate that differences in the synaptic and cellular properties of neurons in the ventrolateral ventromedial hypothalamus (VMHvl) largely account for cross-strain variability in male aggression, and that chemogenetically increasing VMHvl excitability enhances attack behavior in a low-aggression strain. Together, these findings reveal the neuronal implementation of the genetic control of innate aggression level.

neuroscience↗

bioRxiv2021

Molecular Mechanisms of Neurotransmitter Release Control Distinct Features of Sensory Coding Reliability

To survive, animals must recognize reoccurring stimuli. A key requirement for repeated identification of stimuli is reliable representation by the neural code on each encounter. Synaptic transmission underlies neural codes propagation between brain regions. A hallmark of chemical synapses is their plasticity, which enables signal transfer to be modified in an activity-dependent manner. Despite many decades of intense research on synapses, it remains unclear how the plastic features of synaptic transmission can maintain reliable neural coding. By studying the olfactory system of Drosophila melanogaster, we aimed to obtain a deeper mechanistic understanding of how synaptic function shapes neural coding reliability in the live, behaving animal. We show that the properties of the active zone (AZ), the presynaptic site of neurotransmitter release, are critical for generating a reliable neural code. Reducing neurotransmitter release probability specifically at AZs of olfactory sensory neurons disrupted both neural coding and behavioral reliability. Strikingly, these defects were rescued within a day by target-specific synaptic plasticity, whereby a homeostatic increase in the number of AZs compensated the drop in release probability. These findings demonstrate an important role for synaptic plasticity in maintaining neural coding reliability and are of pathophysiological interest by uncovering an elegant mechanism through which the neural circuitry can counterbalance perturbations.

neuroscience↗

bioRxiv2020

Two Parallel Pathways Mediate Olfactory-Driven Backward Locomotion

Although animals switch to backward walking upon sensing an obstacle or danger in their path, the initiation and execution of backward locomotion is poorly understood. The discovery of Moonwalker Descending Neurons (MDNs), made Drosophila useful to study neural circuits underlying backward locomotion. MDNs were demonstrated to receive visual and mechanosensory inputs. However, whether other modalities converge onto MDNs and what are the neural circuits activating MDNs are unknown. We show that aversive but not appetitive olfactory input triggers MDN-mediated backward locomotion. We identify in each hemisphere, a single Moonwalker Subesophageal Zone neuron (MooSEZ), which triggers backward locomotion. MooSEZs act both upstream and in parallel to MDNs. Surprisingly, MooSEZs also respond mostly to aversive odor. Contrary to MDNs, blocking MooSEZs activity has little effect on odor-evoked backward locomotion. Thus, this work reveals another important modality input to MDNs in addition to a novel olfactory pathway and MDN-independent backward locomotion pathway.

neuroscience↗

bioRxiv2018

Inhibitory muscarinic acetylcholine receptors enhance aversive olfactory conditioning in adult Drosophila

Olfactory associative learning in Drosophila is mediated by synaptic plasticity between the Kenyon cells of the mushroom body and their output neurons. Both Kenyon cells and their inputs are cholinergic, yet little is known about the physiological function of muscarinic acetylcholine receptors in learning in adult flies. Here we show that aversive olfactory learning in adult flies requires type A muscarinic acetylcholine receptors (mAChR-A) specifically in the gamma subtype of Kenyon cells. Surprisingly, mAChR-A inhibits odor responses in both Kenyon cell dendrites and axons. Moreover, mAChR-A knockdown impairs the learning-associated depression of odor responses in a mushroom body output neuron. Our results suggest that mAChR-A is required at Kenyon cell presynaptic terminals to depress the synapses between Kenyon cells and their output neurons, and may suggest a role for the recently discovered axo-axonal synapses between Kenyon cells.

neuroscience↗