SLC1A2 and Huntington disease: Kir4.1 potassium channels are expressed primarily by astrocytes and regulate extracellular K+ levels (Kofuji and Newman, 2004) in the CNS, and loss of the glutamate transporter Glt1 (EAAT2) has been extensively studied in the context of HD (Estrada-Sánchez and Rebec, 2012).