Transient extracellular application of gold nanostars increases hippocampal neuronal activity

Kirstie Salinas ,Frank DeLuna,Zurab Kereselidze,Xomalin G. Peralta ,Fidel Santamarı́a

doi:10.1186/preaccept-7863745011292633

Abstract

BackgroundWith 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.ResultsWe 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.ConclusionsOur results show that gold nanoparticles can affect the coding properties of neurons by modifying their excitability.

Highlights

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
We hypothesized that gold nanoparticle-protein interactions alter the electrophysiological properties of neurons, which are mediated by proteins within the neuronal membrane
Our results show that the firing rate of action potentials of these cells increases by 17% after nanoparticle application

Summary

Introduction

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. The aim of this study is to evaluate if gold nanoparticles can affect the normal function of neurons, namely their activity and coding properties. There is a large body of work on the fatal toxic effects of gold nanoparticles on neurons there is little understanding how these widely used nanoparticles might affect their function, namely their activity and coding properties [5]. We hypothesized that gold nanoparticle-protein interactions alter the electrophysiological properties of neurons, which are mediated by proteins within the neuronal membrane.

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Methods

Results