Akinrinade, I. D. | Search bioRxiv

bioRxiv2025

Hypothalamic CRH neurons gate rapid social appraisal of conspecifics

Successful navigation of the social environment requires rapid evaluation of conspecifics to distinguish safe from threatening encounters. While the corticotropin-releasing hormone neurons in the paraventricular nucleus of the hypothalamus (CRHPVN) are well known for orchestrating endocrine stress responses, their role in real-time social appraisal is unknown. Here, using fibre photometry and optogenetics during ethologically relevant social interactions, we show that CRHPVN neurons exhibit a rapid, transient increase in activity that precedes sniffing, an investigative behaviour through which mice gather social information. This transient signal scales with social context: it is heightened during interactions with unfamiliar and aggressive conspecifics and significantly reduced toward familiar partners. Inhibiting these neurons selectively diminished anogenital sniffing, demonstrating their necessity for optimal social evaluation. Strikingly, across repeated exposures to the same conspecific, behavioural investigation declined while CRHPVN activity remained robust, revealing a dissociation between neuronal and behavioural habituation. This persistence suggests that CRHPVN neurons encode stable neural representation of threat during social encounters. Together, our findings identify CRHPVN neurons as a fast, integrative node linking endocrine stress control to rapid social decision-making.

neuroscience↗

bioRxiv2020

20 years of African Neuroscience: Waking a sleeping giant

Understanding the function and dysfunction of the brain remains one of the key challenges of our time. However, an overwhelming majority of brain research is carried out in the Global North, by a minority of well-funded and intimately interconnected labs. In contrast, with an estimated one neuroscientist per million people in Africa, news about neuroscience research from the Global South remains sparse. Clearly, devising new policies to boost Africa’s neuroscience landscape is imperative. However, the policy must be based on accurate data, which is largely lacking. Such data must reflect the extreme heterogeneity of research outputs across the continent’s 54 countries distributed over an area larger than USA, Europe and China combined. Here, we analysed all of Africa’s Neuroscience output over the past 21 years. Uniquely, we individually verified in each of 12,326 publications that the work was indeed performed in Africa and led by African-based researchers. This step is critical: previous estimates grossly inflated figures, because many of Africa’s high-visibility publications are in fact the result of internationally led collaborations, with most work done outside of Africa. The remaining number of African-led Neuroscience publications was 5,219, on average only ~5 per country and year. From here, we extracted metrics such as the journal and citations, as well as detailed information on funding, international collaborations and the techniques and model systems used. We link these metrics to demographic data and indicators of mobility and economy. For reference, we also extracted the same metrics from 220 randomly selected publications each from the UK, USA, Australia, Japan and Brazil. Our unique dataset allows us to gain accurate and in-depth information on the current state of African Neuroscience research, and to put it into a global context. This in turn allows us to make actionable recommendations on how African research might best be supported in the future.Competing Interest StatementThe authors have declared no competing interest.View Full Text

scientific communication and education↗