Figure 1

Selective ablation of orexin neurons in adult orexin-tTA; TetO DTA mice.

(A) Schematic drawing showing the temporally-controlled specific ablation of orexin neurons using the tet-off system in orexin-tTA; TetO DTA mice. In the absence of DOX, orexin neurons are specifically ablated by expressing DTA. (B,C) Immunohistochemical confirmation of DOX-controlled specific ablation of orexin neurons. Coronal sections of the LHA (B) and the CeA (C) of orexin-tTA; TetO DTA mice fed with chow including DOX (DOX(+)) or chow without DOX (DOX(−)) for 4 weeks. Insets in (B) are magnifications of the boxed areas in each panel. (D) Quantitative analysis of the number of orexin-, dynorphin- and MCH-immunoreactive neurons in DOX(−) mice. Each number was normalized using the mean of DOX(+). Data represent the mean ± SEM (n = 3). (E,F) Coronal sections of the LC (E) and PAG (F). These areas include dense nerve endings of orexin neurons in DOX(+) mice. However, these orexin nerve endings were not observed in DOX(−) mice. 4V: fourth ventricle, Aq: Aqueduct, TH: tyrosine hydroxylase.