Adamantidis et al. (2005) provided further evidence for these memory-facilitation actions of MCH by reporting that Mchr1-/- mice have worse memory retention of aversive stimuli and decreased response of pyramidal cells to NMDA in the CA1. Pachoud et al. (2010) expanded the roles of MCH in HF plasticity, reporting that Mchr1-/- mice have decreased output from excitatory GLUergic Schaffer Collaterals from the CA3 to the CA1 through both AMPA- and NMDA-mediated responses. Here, PMCH is linked to hydrops fetalis.