Methamphetamine induces a rapid increase of intracellular Ca(++) levels in neurons overexpressing GCaMP5

Addict Biol. 2016 Mar;21(2):255-66. doi: 10.1111/adb.12193. Epub 2014 Nov 6.

Abstract

In this study, methamphetamine (Meth)- and glutamate (Glu)-mediated intracellular Ca(++) (Ca(++) i) signals were examined in real time in primary cortical neurons overexpressing an intracellular Ca(++) probe, GCaMP5, by adeno-associated viral (AAV) serotype 1. Binding of Ca(++) to GCaMP increased green fluorescence intensity in cells. Both Meth and Glu induced a rapid increase in Ca(++) i, which was blocked by MK801, suggesting that Meth enhanced Ca(++) i through Glu receptor in neurons. The Meth-mediated Ca(++) signal was also blocked by Mg(++) , low Ca(++) or the L-type Ca(++) channel inhibitor nifedipine. The ryanodine receptor inhibitor dantrolene did not alter the initial Ca(++) influx but partially reduced the peak of Ca(++) i. These data suggest that Meth enhanced Ca(++) influx through membrane Ca(++) channels, which then triggered the release of Ca(++) from the endoplasmic reticulum in the cytosol. AAV-GCaMP5 was also injected to the parietal cortex of adult rats. Administration of Meth enhanced fluorescence in the ipsilateral cortex. Using immunohistochemistry, Meth-induced green fluorescence was found in the NeuN-containing cells in the cortex, suggesting that Meth increased Ca(++) in neurons in vivo. In conclusion, we have used in vitro and in vivo techniques to demonstrate a rapid increase of Ca(++) i by Meth in cortical neurons through overexpression of GCaMP5. As Meth induces behavioral responses and neurotoxicity through Ca(++) i, modulation of Ca(++) i may be useful to reduce Meth-related reactions.

Keywords: Calcium; glutamate; magnesium; methamphetamine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Calcium / metabolism*
  • Calcium Channel Blockers / pharmacology
  • Calcium Channels / drug effects
  • Calcium-Binding Proteins / metabolism
  • Calmodulin / metabolism
  • Cells, Cultured
  • Cerebral Cortex / drug effects
  • Dantrolene / pharmacology
  • Dizocilpine Maleate / pharmacology
  • Dopamine Agents / pharmacology*
  • Excitatory Amino Acid Antagonists / pharmacology
  • Female
  • Glutamic Acid / pharmacology*
  • Green Fluorescent Proteins / metabolism
  • Indicators and Reagents / pharmacology
  • Male
  • Methamphetamine / pharmacokinetics*
  • Muscle Relaxants, Central / pharmacology
  • Neurons / metabolism*
  • Nifedipine / pharmacology
  • Rats, Sprague-Dawley
  • Recombinant Fusion Proteins / metabolism
  • Signal Transduction / drug effects

Substances

  • Calcium Channel Blockers
  • Calcium Channels
  • Calcium-Binding Proteins
  • Calmodulin
  • Dopamine Agents
  • Excitatory Amino Acid Antagonists
  • Indicators and Reagents
  • Muscle Relaxants, Central
  • Recombinant Fusion Proteins
  • Green Fluorescent Proteins
  • Glutamic Acid
  • Methamphetamine
  • Dizocilpine Maleate
  • Dantrolene
  • Nifedipine
  • Calcium