Norepinephrine-deficient mice have increased susceptibility to seizure- inducing stimuli

Patricia Szot, David Weinshenker, Sylvia S. White, Carol A. Robbins, Nicole C. Rust, Philip A Schwartzkroin, Richard D. Palmiter

Research output: Contribution to journalArticle

94 Scopus citations

Abstract

Several lines of evidence suggest that norepinephrine (NE) can modulate seizure activity. However, the experimental methods used in the past cannot exclude the possible role of other neurotransmitters coreleased with NE from noradrenergic terminals. We have assessed the seizure susceptibility of genetically engineered mice that lack NE. Seizure susceptibility was determined in the dopamine β-hydroxylase null mutant (Dbh -/-) mouse using four different convulsant stimuli: 2,2,2-trifluroethyl ether (flurothyl), pentylenetetrazol (PTZ), kainic acid, and high-decibel sound. Dbh -/- mice demonstrated enhanced susceptibility (i.e., lower threshold) compared with littermate heterozygous (Dbh +/-) controls to flurothyl, PTZ, kainic acid, and audiogenic seizures and enhanced sensitivity (i.e., seizure severity and mortality) to flurothyl, PTZ, and kainic acid. c-Fos mRNA expression in the cortex, hippocampus (CA1 and CA3), and amygdala was increased in Dbh -/- mice in association with flurothyl-induced seizures. Enhanced seizure susceptibility to flurothyl and increased seizure-induced c-fos mRNA expression were reversed by pretreatment with L-threo-3,4- dihydroxyphenylserine, which partially restores the NE content in Dbh -/- mice. These genetically engineered mice confirm unambiguously the potent effects of the noradrenergic system in modulating epileptogenicity and illustrate the unique opportunity offered by Dbh -/- mice for elucidating the pathways through which NE can regulate seizure activity.

Original languageEnglish (US)
Pages (from-to)10985-10992
Number of pages8
JournalJournal of Neuroscience
Volume19
Issue number24
StatePublished - Dec 15 1999
Externally publishedYes

Keywords

  • C-fos mRNA
  • Dopamine β-hydroxylase
  • Epilepsy
  • Flurothyl
  • Kainic acid
  • Norepinephrine
  • Seizure

ASJC Scopus subject areas

  • Neuroscience(all)

Fingerprint Dive into the research topics of 'Norepinephrine-deficient mice have increased susceptibility to seizure- inducing stimuli'. Together they form a unique fingerprint.

  • Cite this

    Szot, P., Weinshenker, D., White, S. S., Robbins, C. A., Rust, N. C., Schwartzkroin, P. A., & Palmiter, R. D. (1999). Norepinephrine-deficient mice have increased susceptibility to seizure- inducing stimuli. Journal of Neuroscience, 19(24), 10985-10992.