PITX3 and congenital primary aphakia: The role of cholinergic striatal interneurons in LIDs has been recently explored in a study with 6OHDA-lesioned or Pitx3-deficient aphakia mice (Pitx3-ak/ak), which show nigrostriatal dopaminergic deficits.70 One of the outcomes of the study was the expression extracellular signal-regulated kinase1/2 (ERK), which is thought to mediate the expression of LIDs.