Accordingly, OX neurons directly sense energy status: fasting (forced hypoglycemia) increases OX expression (Cai et al., 1999) and activation of OX neurons, while physiologic increases in glucose that occur with re-feeding or satiation selectively inhibit OX neurons (Burdakov et al., 2005; Williams et al., 2008). Here, HCRT is linked to Hypoglycemia.