Link Original: Jaime M. Monti, The neurotransmitters of sleep and wake, a physiological reviews series, Sleep Medicine Reviews, Volume 17, Issue 4, 2013, Pages 313-315, ISSN 1087-0792, https://doi.org/10.1016/j.smrv.2013.02.004. (http://www.sciencedirect.com/…/article/pii/S1087079213000270) (imagem adaptada de Shutterstock)
