Downregulation of HCN1 channels in hippocampus and prefrontal cortex in methamphetamine re-exposed mice with enhanced working memory

Physiol Res. 2019 Mar 6;68(1):107-117. doi: 10.33549/physiolres.933873. Epub 2018 Oct 23.

Abstract

The hyperpolarization-activated cyclic-nucleotide-gated non-selective cation (HCN) channels play a potential role in the neurological basis underlying drug addiction. However, little is known about the role of HCN channels in methamphetamine (METH) abuse. In the present study, we examined the changes in working memory functions of METH re-exposed mice through Morris water maze test, and investigated the protein expression of HCN1 channels and potential mechanisms underlying the modulation of HCN channels by Western blotting analysis. Mice were injected with METH (1 mg/kg, i.p.) once per day for 6 consecutive days. After 5 days without METH, mice were re-exposed to METH at the same concentration. We found that METH re-exposure caused an enhancement of working memory, and a decrease in the HCN1 channels protein expression in both hippocampus and prefrontal cortex. The phosphorylated extracellular regulated protein kinase 1/2 (p-ERK1/2), an important regulator of HCN channels, was also obviously reduced in hippocampus and prefrontal cortex of mice with METH re-exposure. Meanwhile, acute METH exposure did not affect the working memory function and the protein expressions of HCN1 channels and p-ERK1/2. Overall, our data firstly showed the aberrant protein expression of HCN1 channels in METH re-exposed mice with enhanced working memory, which was probably related to the down-regulation of p-ERK1/2 protein expression.

MeSH terms

  • Animals
  • Down-Regulation / drug effects
  • Down-Regulation / physiology*
  • Hippocampus / drug effects
  • Hippocampus / metabolism*
  • Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels / antagonists & inhibitors
  • Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels / biosynthesis*
  • Locomotion / drug effects
  • Locomotion / physiology
  • Male
  • Memory, Short-Term / drug effects
  • Memory, Short-Term / physiology*
  • Methamphetamine / administration & dosage
  • Methamphetamine / toxicity*
  • Mice
  • Mice, Inbred C57BL
  • Potassium Channels / biosynthesis*
  • Prefrontal Cortex / drug effects
  • Prefrontal Cortex / metabolism*
  • Random Allocation

Substances

  • Hcn1 protein, mouse
  • Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels
  • Potassium Channels
  • Methamphetamine