Biology subjects

Avitan, L.

Publications and source records attributed to Avitan, L..

7 recordsLinked to original sources

bioRxiv2025

It is about time: neural temporal scaling accounts for robust hunting behavior across temperatures

Animals are often required to maintain stable performance in critical behaviors despite environmental fluctuations. Temperature broadly affects neural activity, and even localized shifts in brain temperature can alter behavior. However, whether widespread changes across the brain, such as those experienced by ectotherms, disrupt survival-critical behaviors remains unclear. Here, we show that larval zebrafish maintain robust hunting performance across a 10{degrees}C ecological range. Although behavior accelerates with temperature, spatial parameters, such as bout distance and turn angle, remain stable. This invariance results from coordinated adjustments in tail beat frequency and movement duration. Brain-wide calcium imaging revealed that behavioral temporal scaling is mirrored at the level of single neurons. A simple rate model showed that temperature-dependent changes in neural time constants can account for compensatory tail dynamics, enabling stability without active regulation. These findings suggest that neural temporal scaling can preserve performance under diffuse temperature fluctuations, supporting robust behavior in natural environments.

neuroscience↗

bioRxiv2025

Distinct brain-wide neural dynamics predict social approach behavior

Social behavior is essential for animal survival and adaptation, requiring the integration of sensory cues to guide interactions with conspecifics. A key component of social behavior is approach, where animals actively move to-ward social partners to maintain group cohesion, establish affiliations, and coordinate actions. While a continuous stream of social information is encoded across sensory modalities, it remains unclear whether a distinct neural process underlies social approach. Here, we developed a novel assay in which a head-fixed, tail-free zebrafish interacts with a freely swimming conspecific, enabling precise quantification of social behavior alongside whole-brain functional imaging at cellular resolution. We demonstrate that zebrafish approach behavior is jointly shaped by spatial and temporal information from conspecifics rather than by these features acting independently. Social approach behavior is preceded by distinct brain-wide neural activity patterns emerging seconds before movement onset, characterized by increased activity in a small subset of forebrain neurons and decreased activity in midbrain and hindbrain neuronal populations. These activity patterns reliably predict upcoming approach movements from each of these regions separately. Moreover, the extent to which neural activity distinguishes approach from non-approach movements predicts individual differences in social behavior, directly linking neural dynamics to behavioral variability. Together, our findings reveal a neural mechanism underlying social approach behavior, highlighting how a distributed yet functionally coordinated network facilitates social interaction.

neuroscience↗

bioRxiv2024

A complete account of the behavioral repertoire uncovers principles of larval zebrafish hunting behavior

In goal-directed behavior animals select actions from a diverse repertoire of possible movements. Accurately quantifying the complete behavioral repertoire can uncover the underlying rules that guide such goal-directed behavior. However, these movements are usually complex, high-dimensional, and lead to various outcomes, posing a challenge to fully capture the complete repertoire. By tracking freely hunting zebrafish larvae using a highspeed camera and analyzing their movements, we developed a mathematical model that accurately reproduces the complete repertoire. Using the model, we show that fish position and change in heading angle following a movement are coupled, such that the choice of one of them limits the possibilities of the other. This repertoire structure uncovered fundamental principles of movements, showing that fish rotate around an identified rotation point and then move forward or backward along straight lines. From the uncovered movement principles, we identified a new guiding rule for prey interaction: in each movement, fish turn to face the prey and then move forward or backward. This enables decoupling between orientation and distance selections of the fish during the hunt. These results provide a comprehensive and continuous description of the repertoire of movements, reveal underlying algorithmic rules that govern the behavior, and offer insights into the potential neural implementation of the repertoire.

neuroscience↗

bioRxiv2023

Cortical activity emerges in region-specific patterns during early brain development

The development of precise neural circuits in the brain requires spontaneous patterns of neural activity prior to functional maturation. In the rodent cerebral cortex patchwork and wave patterns of activity develop in somatosensory and visual regions, respectively, and are present at birth. However, whether such activity patterns occur in non-eutherian mammals, as well as when and how they arise during development remain open questions relevant to understand brain formation in health and disease. Since the onset of patterned cortical activity is challenging to study prenatally in eutherians, here we offer a new approach in a minimally invasive manner using marsupial dunnarts, whose cortex forms postnatally. We discovered similar patchwork and travelling waves in the dunnart somatosensory and visual cortices at stage 27 (equivalent to newborn mice), and examined progressively earlier stages of development to determine their onset and how they first emerge. We observed that these patterns of activity emerge in a region-specific and sequential manner, becoming evident as early as stage 24 in somatosensory and stage 25 in visual cortices (equivalent to embryonic day 16 and 17, respectively, in mice), as cortical layers establish and thalamic axons innervate the cortex. In addition to sculpting synaptic connections of existing circuits, evolutionarily conserved patterns of neural activity could therefore help regulate early events in cortical development. Significance StatementRegion-specific patterns of neural activity are present at birth in rodents and are thought to refine synaptic connections during critical periods of cerebral cortex development. Marsupials are born much more immature than rodents, allowing the investigation of how these patterns arise in vivo. We discovered that cortical activity patterns are remarkably similar in marsupial dunnarts and rodents, and that they emerge very early, before cortical neurogenesis is complete. Moreover, they arise from the outset in different patterns specific to somatosensory and visual areas (i.e., patchworks and waves) indicating they may also play evolutionarily conserved roles in cortical regionalization during development.

neuroscience↗

bioRxiv2021

fmr1 mutation interacts with sensory experience to alter the early development of behavior and sensory coding in zebrafish

While Autism Spectrum Disorders (ASDs) are developmental in origin little is known about how they affect the early development of behavior and sensory coding, or how this is modulated by the sensory environment. The most common inherited form of autism is Fragile X syndrome, caused by a mutation in FMR1. Here we show that zebrafish fmr1-/- mutant larvae raised in a naturalistic visual environment display early deficits in hunting behavior, tectal map development, tectal network properties and decoding of spatial stimuli. However when given a choice they preferred an environment with reduced visual stimulation, and rearing them in this environment improved these metrics. Older fmr1-/- fish showed differences in social behavior, spending more time observing a conspecific, but responding more slowly to social cues. Together these results help reveal how fmr1-/- changes the early development of vertebrate brain function, and how manipulating the environment could potentially help reduce these changes.

neuroscience↗

bioRxiv2019

Behavioral signatures of a developing neural code

During early life neural codes must develop to appropriately transform sensory inputs into behavioral outputs. Here we demonstrate a direct link between the maturity of neural coding in the visual brain and developmental changes in visually-guided behavior. In zebrafish larvae we show that visually-driven hunting behavior improves from 4 to 15 days post-fertilization, becoming faster and more accurate. During the same period population activity in the optic tectum refines, leading to improved decoding and information transmission of spatial position, particularly in the representation of the frontal visual field. Remarkably, individual differences in decoding can predict each fishs hunting success. Together these results show how the neural codes required to subserve a natural behavior emerge during development.

neuroscience↗

bioRxiv2019

Model-based decoupling of evoked and spontaneous neural activity in calcium imaging data

The pattern of neural activity evoked by a stimulus can be substantially affected by ongoing spontaneous activity. Separating these two types of activity is particularly important for calcium imaging data given the slow temporal dynamics of calcium indicators. Here we present a statistical model that decouples stimulus-driven activity from low dimensional spontaneous activity in this case. The model identifies hidden factors giving rise to spontaneous activity while jointly estimating stimulus tuning properties that account for the confounding effects that these factors introduce. By applying our model to data from zebrafish optic tectum and mouse visual cortex, we obtain quantitative measurements of the extent that neurons in each case are driven by evoked activity, spontaneous activity, and their interaction. This broadly applicable model brings new insight into population-level neural activity in single trials without averaging away potentially important information encoded in spontaneous activity.

neuroscience↗