Dan, U. | bioRxiv Science

bioRxiv2026

Building neuroanatomical resources for three-spined sticklebacks: Brain areas important for social behavior

IntroductionThree-spined stickleback fish are famous for their diversity and charismatic social behavior. However, there are few neuroanatomical resources for studying the neural and brain mechanisms underlying their fascinating behavior. Methods and ResultsWe identify 11 brain areas important for social behavior by referencing brain atlases for six other teleost fishes. Brain regions were identified via neuroanatomical landmarks and we characterized the presence / absence of tyrosine hydroxylase (TH), a key gene product of the dopaminergic system, in those regions. Comparing the neuroanatomical location of these regions in the stickleback brain and the expression of TH therein to that of other fish species highlights similarities and differences and the need for a brain atlas specific to sticklebacks. This resource serves as a map of the location of regions important for social behavior in the stickleback brain. ConclusionThis resource will help guide future studies connecting gene function to social behavior through the brain and will enable future work to understand the evolution of neural mechanisms that contribute to the diversity of social behavior in this emerging model organism.

neuroscience↗

bioRxiv2024

Dysregulation of the fluid homeostasis system by aging

Chronic dehydration is a leading cause of morbidity for the elderly, but how aging alters the fluid homeostasis system is not well understood. Here, we used a combination of physiologic, behavioral and circuit analyses to characterize how fluid balance is affected by aging in mice. We found that old mice have a primary defect in sensing and producing the anti-diuretic hormone vasopressin, which results in chronic dehydration. Recordings and manipulations of the thirst circuitry revealed that old mice retain the ability to sense systemic cues of dehydration but are impaired in detecting presystemic, likely oropharyngeal, cues generated during eating and drinking, resulting in disorganized drinking behavior on short timescales. Surprisingly, old mice had increased drinking and motivation after 24-hour water deprivation, indicating that aging does not result in a general impairment in the thirst circuit. These findings reveal how a homeostatic system undergoes coordinated changes during aging.

neuroscience↗