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Modification of hippocampal excitability in brain slices pretreated with a low nanomolar concentration of Zn 2+
Author(s) -
Takeda Atsushi,
Shakushi Yukina,
Tamano Haruna
Publication year - 2015
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.23629
Subject(s) - chemistry , slice preparation , hippocampal formation , stimulation , extracellular , glutamate receptor , biophysics , intracellular , mossy fiber (hippocampus) , biochemistry , neuroscience , biology , in vitro , receptor , dentate gyrus
Synaptic Zn 2+ homeostasis may be changed during brain slice preparation. However, much less attention has been paid to Zn 2+ in artificial cerebrospinal fluid (ACSF) used for slice experiments than has been paid to Ca 2+ . The present study assesses addition of Zn 2+ to ACSF, focused on hippocampal excitability after acute brain slice preparation. When the static levels of intracellular Zn 2+ and Ca 2+ were compared between brain slices prepared with conventional ACSF without Zn 2+ and those pretreated with ACSF containing 20 nM ZnCl 2 for 1 hr, both levels were almost the same. On the other hand, intracellular Ca 2+ levels were significantly increased in the stratum lucidum of the control brain slices after stimulation with high K + , although the increase was significantly suppressed by the pretreatment with ACSF containing Zn 2+ , suggesting that neuronal excitation is enhanced in brain slices prepared with ACSF without Zn 2+ . The increase in extracellular Zn 2+ level, an index of glutamate release, after stimulation with high K + was also significantly suppressed by pretreatment with ACSF containing Zn 2+ . When mossy fiber excitation was assessed in brain slices with FM4‐64, an indicator of presynaptic activity, attenuation of FM 4‐64 fluorescence based on presynaptic activity was suppressed in the stratum lucidum of brain slices pretreated with ACSF containing Zn 2+ . The present study indicates that hippocampal excitability is enhanced in brain slices prepared with ACSF without Zn 2+ . It is likely that a low nanomolar concentration of Zn 2+ is necessary for ACSF. © 2015 Wiley Periodicals, Inc.