title: Intracellular gold nanoparticles increase neuronal excitability and aggravate seizure activity in the mouse brain.
abstract: Due to their inert property, gold nanoparticles (AuNPs) have drawn considerable attention; their biological application has recently expanded to include nanomedicine and neuroscience. However, the effect of AuNPs on the bioelectrical properties of a single neuron remains unknown. Here we present the effect of AuNPs on a single neuron under physiological and pathological conditions in vitro. AuNPs were intracellularly applied to hippocampal CA1 neurons from the mouse brain. The electrophysiological property of CA1 neurons treated with 5- or 40-nm AuNPs was assessed using the whole-cell patch-clamp technique. Intracellular application of AuNPs increased both the number of action potentials (APs) and input resistance. The threshold and duration of APs and the after hyperpolarization (AHP) were decreased by the intracellular AuNPs. In addition, intracellular AuNPs elicited paroxysmal depolarizing shift-like firing patterns during sustained repetitive firings (SRF) induced by prolonged depolarization (10 sec). Furthermore, low Mg2+-induced epileptiform activity was aggravated by the intracellular AuNPs. In this study, we demonstrated that intracellular AuNPs alter the intrinsic properties of neurons toward increasing their excitability, and may have deleterious effects on neurons under pathological conditions, such as seizure. These results provide some considerable direction on application of AuNPs into central nervous system (CNS).
authors.affiliation: Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
authors.forename: Seungmoon
authors.initials: S
authors.lastname: Jung
authors.affiliation: Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
authors.forename: Minji
authors.initials: M
authors.lastname: Bang
authors.affiliation: Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
authors.forename: Byung Sun
authors.initials: BS
authors.lastname: Kim
authors.affiliation: Department of Biomedical Engineering, Khalifa University of Science, Technology, and Research, Abu Dhabi, United Arab Emirates.
authors.forename: Sungmun
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan, United States of America.
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Kotov
authors.affiliation: Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
authors.forename: Bongsoo
authors.initials: B
authors.lastname: Kim
authors.affiliation: Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
authors.forename: Daejong
authors.initials: D
authors.lastname: Jeon
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000503:physiopathology*; D056547:CA1 Region, Hippocampal / Q000166:cytology / Q000503:physiopathology; D016503:Drug Delivery Systems; D006046:Gold / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry; D008297:Male; D053768:Metal Nanoparticles / Q000737:chemistry*; D051379:Mice; D008810:Mice, Inbred C57BL; D050997:Nanomedicine; D009474:Neurons / Q000187:drug effects / Q000473:pathology; D018408:Patch-Clamp Techniques; D012640:Seizures / Q000503:physiopathology*
chemical_list: D006046:Gold; D008274:Magnesium