NR4A1 and autism: However, both high and low levels of NR4A1 have been linked to mental health issues as cortical levels of NR4A1 were reported to be decreased in autism and schizophrenia (Corley et al., 2016; Li et al., 2016) and NR4A1 knockouts exhibit learning disabilities (McNulty et al., 2012) as well as transgenic mice with dominant-negative NR4A1 that showed defects of synaptic plasticity (Hawk et al., 2012; Bridi and Abel, 2013).