Biology subjects

Peedikayil-Kurien, S.

Publications and source records attributed to Peedikayil-Kurien, S..

3 recordsLinked to original sources

bioRxiv2023

Modulation by NPYR underlies experience-dependent, sexually dimorphic learning

The evolutionary paths taken by each sex within a given species sometimes diverge, resulting in behavioral differences. Given their distinct needs, the mechanism by which each sex learns from a shared experience is still an open question. Here, we reveal sexual dimorphism in learning: C. elegans males do not learn to avoid the pathogenic bacteria PA14 as efficiently and rapidly as hermaphrodites. Notably, neuronal activity following pathogen exposure was dimorphic: hermaphrodites generate robust representations, while males, in line with their behavior, exhibit contrasting representations. Transcriptomic and behavioral analysis revealed that the neuropeptide receptor npr-5, an ortholog of the mammalian NPY receptor, regulates male learning by modulating neuronal activity. Furthermore, we show the dependency of the males decision-making on their sexual status and demonstrate the pivotal role of npr-5 as a modulator of incoming sensory cues. Taken together, we portray sex-specific plasticity in behavior toward a shared experience by modulating learning.

neuroscience↗

bioRxiv2023

Sex-Specific Developmental Gene Expression Atlas Unveils Dimorphic Gene Networks in C. elegans

Sex-specific traits and behaviors emerge during development by the acquisition of unique properties in the nervous system of each sex. However, the genetic events responsible for introducing these sex-specific features remain poorly understood. In this study, we created a comprehensive gene expression atlas for both sexes of the nematode Caenorhabditis elegans across development. By comparing the transcriptome of pure populations of hermaphrodites and males from early larval stages to adulthood, we discovered numerous differentially expressed genes, including neuronal gene families like transcription factors, neuropeptides, and GPCRs. We identified INS-39, an insulin-like peptide, as a prominent male-biased gene expressed specifically in ciliated sensory neurons. We show that INS-39 serves as an early-stage male marker, facilitating the effective isolation of males in high-throughput experiments. Through complex and sex-specific regulation, ins-39 plays pleiotropic sexually-dimorphic roles in temperature sensation, survival in cold temperatures, resilience against high hydrogen peroxide levels, and dauer entry, while also playing a shared, dimorphic role in early life stress. This study offers a comparative sexual and developmental gene expression database for C. elegans, which will facilitate research into the genetic regulation of the sexual development of other organisms. Furthermore, it highlights conserved candidate genes that may underlie the sexually-dimorphic manifestation of different human diseases.

neuroscience↗

bioRxiv2023

Integration of spatially opposing cues by a single interneuron guides decision making in C. elegans

The capacity of animals to integrate and respond to multiple hazardous stimuli in the surroundings is crucial for their survival. In mammals, complex evaluations of the environment require large numbers and different subtypes of neurons. The nematode C. elegans avoid hazardous chemicals they encounter by reversing their direction of movement. How does the worms compact nervous system processes the spatial information and directs the change of motion? We show here that a single interneuron, AVA, receives glutamatergic excitatory signals from head sensory neurons and glutamatergic inhibitory signals from the tail sensory neurons. AVA integrates the spatially distinct and opposing cues, whose output instructs the animals behavioral decision. We further find that the differential activation of AVA from the head and tail stems from distinct anatomical localization of inhibitory and excitatory glutamate-gated receptors along the AVA process, and from different threshold sensitivities of the sensory neurons to aversive stimuli. Our results thus uncover a cellular mechanism that mediates spatial computation of nociceptive cues for efficient decision-making in C. elegans.

neuroscience↗