Journal article

Hyperdipsia in sheep bearing lesions in the medial septal nucleus

A Smardencas, DA Denton, MJ McKinley

BRAIN RESEARCH | ELSEVIER | Published : 2021


Previous experiments in rodents showed that ablation of the septal brain region caused hyperdipsia. We investigated which part of the septal region needs ablation to produce hyperdipsia in sheep, and whether increased drinking was a primary hyperdipsia. Following ablation of the medial septal region (n = 5), but not parts of the lateral septal region (n = 4), daily water intake increased from ~2.5-5 L/day up to 10 L/day for up to 3 months post-lesion. In hyperdipsic sheep, plasma osmolality increased on the first day post-lesion and body weight fell, suggesting that initial hyperdipsia was secondary to fluid loss. However hyperosmolality was not sustained long-term and plasma hypo-osmolality..

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Funding Acknowledgements

This work was funded by the G. Harold and Leila Y. Mathers Foundation, the Robert B Jr and Helen C Kleberg Foundation and the Victorian Government Operational Infrastructure Scheme. MMcK was supported by a Fellowship from the National Health and Medical Research Council of Australia. We also thank S Baillieu Myer, Diana Gibson, Mark Nelson, Robert Albert, Tim Jones, Jeanne Pratt and Marcus Besen for their generous support. These funding sources had no involvement in study design, collection, analysis and interpretation of data; in the writing of the report: and in the decision to submit the article for publication.