You're right, it doesn't appear in the actual paper [ https://www.nature.com/articles/s41598-023-39344-7 https://www.nature.com/articles/s41598-023-39344-7 ] ei

You're right, it doesn't appear in the actual paper [ https://www.nature.com/articles/s41598-023-39344-7 https://www.nature.com/articles/s41598-023-39344-7 ] either, except for this pathetic disclaimer: Ethics declarations: Competing interests The authors declare no competing interests. There are also no occurrences of the terms "society", "moral", "distress", or "stress". I'm surprised this work got approval from the Institutional Animal Care & Use Committee. https://olaw.nih.gov/resources/tutorials/iacufoot.htm https://olaw.nih.gov/resources/tutorials/iacufoot.htm Criteria for IACUC Review and Approval of Protocols: ... d. The living conditions of animals will be appropriate for their species and contribute to their health and comfort. ... I can hardly see how this living brain is having living conditions appropriate to the Sus domesticus (domesticated pig) species. The living conditions are totally unnatural and seem to be in direct violation of item d of the IACUC approval criteria.