Fig. 1.

Parabiosis types and timelines. A This figure illustrates the four distinct experimental groups in our study, each represented by a unique combination of young (Y) and aged (A) parabionts, designated by the co-parabiont in parentheses. These groups include isochronic young (Y-(Y)), heterochronic young (Y-(A)), heterochronic aged (A-(Y)), and isochronic aged (A-(A)) parabionts. B The timeline for the parabiosis surgery procedure is depicted. Five days prior to surgery, mice are acclimated and assessed for potential aggression. Following surgery, animals are subjected to a meticulous 14-day monitoring period. Neurovascular coupling responses are evaluated in parabionts 6 weeks post-surgery. C This graph provides an overview of the comprehensive pre- and postsurgical care regimen administered to parabionts. To effectively manage pain and inflammation, parabionts receive treatment with buprenorphine and meloxicam. To prevent infection, surgery is performed in aseptic conditions and parabionts receive daily enrofloxacin injections for seven consecutive days. To prevent dehydration, parabionts are injected with warm saline. D Representative flow cytometry graph displaying mononuclear cells isolated from the blood of the non-injected parabiont. The graph emphasizes the presence of phycoerythrin-labeled leukocytes within the top gate, which originate from the injected co-parabiont. This observation serves as conclusive evidence confirming the successful exchange of blood between the parabionts