The Echidna Tachyglossus aculeatus Combines REM and Non-REM Aspects in a Single Sleep State: Implications for the Evolution of Sleep

This work was supported by the Medical Research Service of the Veterans Administration, US Public Health Service Grants NS32819 and NS14610, and the Australian Research Council Special Research Centres Budget. We thank Joel Benington for help with spectral analysis of the echidna EEG. This research was carried out according to the Australian Code of Practice for the Care and Use of Animals for Scientific Purposes under Queensland National Parks and Wildlife permits T00803 and K01782.

Correspondence should be addressed to Jerome Siegel, Department of Psychiatry, UCLA, Neurobiology Research 151A3, VAMC, 16111 Plummer Street, North Hills, CA 91343.