Neuroethology in The Age of Gene Editing: New Tools And Novel Insights into The Molecular And Neural Basis of Behavior

Revisiting the specific and potentially independent role of the gonad in hormone regulation and reproductive behavior

Gonadal sex steroid hormones are well-studied modulators of reproductive physiology and behavior. Recent behavioral endocrinology research has focused on how the brain dynamically responds to - and may even produce - sex steroids, but the gonadal tissues that primarily release these hormones receive much less attention as a potential mediator of behavioral variation. This Commentary revisits mechanisms by which the reproductive hypothalamic-pituitary-gonadal (HPG) axis can be modulated specifically at the gonadal level. These mechanisms include those that may allow the gonad to be regulated independently of the HPG axis, such as receptors for non-HPG hormones, neural inputs and local production of conventional 'neuropeptides'. Here, I highlight studies that examine variation in these gonadal mechanisms in diverse taxa, with an emphasis on recent transcriptomic work. I then outline how future work can establish functional roles of gonadal mechanisms in reproductive behavior and evaluate gonad responsiveness to environmental cues. When integrated with neural mechanisms, further investigation of gonadal hormone regulation can yield new insight into the control and evolution of steroid-mediated traits, including behavior.

A perspective on neuroethology: what the past teaches us about the future of neuroethology

For 100 years, the Journal of Comparative Physiology-A has significantly supported research in the field of neuroethology. The celebration of the journal's centennial is a great time point to appreciate the recent progress in neuroethology and to discuss possible avenues of the field. Animal behavior is the main source of inspiration for neuroethologists. This is illustrated by the huge diversity of investigated behaviors and species. To explain behavior at a mechanistic level, neuroethologists combine neuroscientific approaches with sophisticated behavioral analysis. The rapid technological progress in neuroscience makes neuroethology a highly dynamic and exciting field of research. To summarize the recent scientific progress in neuroethology, I went through all abstracts of the last six International Congresses for Neuroethology (ICNs 2010-2022) and categorized them based on the sensory modalities, experimental model species, and research topics. This highlights the diversity of neuroethology and gives us a perspective on the field's scientific future. At the end, I highlight three research topics that may, among others, influence the future of neuroethology. I hope that sharing my roots may inspire other scientists to follow neuroethological approaches.