Shukhan Ng1, Nicole Y Y Wicha2. 1. Department of Biology, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249, USA. 2. Department of Biology, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249, USA ; Neurosciences Institute, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249, USA ; Research Imaging Institute, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, Texas 78229, USA.