When the membrane potential reaches approximately – 60 mV , the K channels open up and the Na channels close and the prepotential phase begins again . When the membrane potential reaches approximately − 60 mV , the K channels open and Na channels close and the prepotential phase begins again .
Apabila potensi membran mencapai kira-kira  60 mV, saluran K dibuka dan saluran Na ditutup dan fasa potensi bermula lagi. Apabila potensi membran mencapai kira-kira  60 mV, saluran K terbuka dan saluran Na ditutup dan fasa potensi bermula lagi.