title: Transient extracellular application of gold nanostars increases hippocampal neuronal activity.
abstract: BACKGROUND
  With the increased use of nanoparticles in biomedical applications there is a growing need to understand the effects that nanoparticles may have on cell function. Identifying these effects and understanding the mechanism through which nanoparticles interfere with the normal functioning of a cell is necessary for any therapeutic or diagnostic application. The aim of this study is to evaluate if gold nanoparticles can affect the normal function of neurons, namely their activity and coding properties.
  
  
  RESULTS
  We synthesized star shaped gold nanoparticles of 180 nm average size. We applied the nanoparticles to acute mouse hippocampal slices while recording the action potentials from single neurons in the CA3 region. Our results show that CA3 hippocampal neurons increase their firing rate by 17% after the application of gold nanostars. The increase in excitability lasted for as much as 50 minutes after a transient 5 min application of the nanoparticles. Further analyses of the action potential shape and computational modeling suggest that nanoparticles block potassium channels responsible for the repolarization of the action potentials, thus allowing the cell to increase its firing rate.
  
  
  CONCLUSIONS
  Our results show that gold nanoparticles can affect the coding properties of neurons by modifying their excitability.
authors.affiliation: UTSA Neurosciences Institute, The University of Texas at San Antonio, San Antonio, Texas, 78249, USA. kirstiesalinas@ymail.com.
authors.forename: Kirstie
authors.initials: K
authors.lastname: Salinas
authors.affiliation: Department of Physics and Astronomy, The University of Texas at San Antonio, San Antonio, Texas, 78249, USA. yjd888@my.utsa.edu.
authors.forename: Zurab
authors.initials: Z
authors.lastname: Kereselidze
authors.affiliation: UTSA Neurosciences Institute, The University of Texas at San Antonio, San Antonio, Texas, 78249, USA. rhx138@my.utsa.edu.
authors.forename: Frank
authors.initials: F
authors.lastname: DeLuna
authors.affiliation: Department of Physics and Astronomy, The University of Texas at San Antonio, San Antonio, Texas, 78249, USA. Xomalin.peralta@utsa.edu.
authors.forename: Xomalin G
authors.initials: XG
authors.lastname: Peralta
authors.affiliation: UTSA Neurosciences Institute, The University of Texas at San Antonio, San Antonio, Texas, 78249, USA. fidel.santamaria@utsa.edu.
authors.forename: Fidel
authors.initials: F
authors.lastname: Santamaria
mesh_terms: D000200:Action Potentials; D000818:Animals; D006046:Gold / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects*; D066298:In Vitro Techniques; D053768:Metal Nanoparticles / Q000008:administration & dosage / Q000737:chemistry*; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D011188:Potassium / Q000378:metabolism; D026902:Potassium Channel Blockers / Q000737:chemistry / Q000494:pharmacology; D013052:Spectrometry, X-Ray Emission
chemical_list: D026902:Potassium Channel Blockers; D006046:Gold; D011188:Potassium