Airjet and FG-7142-induced Fos expression differs in rats selectively bred for high and low anxiety-related behavior.
We reported recently that two rat lines bred for either high (HAB) or low (LAB) anxiety-related behavior display differential Fos expression in restricted parts of the fear/anxiety circuitry when exposed to mild anxiety evoked in exploratory anxiety tests. Since different forms of anxiety are thought to activate different parts of the anxiety circuitry, we investigated now whether (1) an aversive stimulus which elicits escape behavior (airjet) and (2) the anxiogenic/panicogenic drug FG-7142 would reveal further differences in Fos expression as a marker of neuronal activation between HAB and LAB rats. Both airjet exposure and FG-7142 induced Fos expression in both lines in various anxiety-related brain areas. HAB rats, which displayed exaggerated escape responses during airjet exposure, exhibited increased Fos expression in brain areas including the hypothalamus, periaqueductal gray and locus coeruleus, as well as blunted Fos activation in the cingulate cortex in response to airjet and/or FG-7142. The results corroborate previous findings showing that trait anxiety affects neuronal excitability in hypothalamic and medial prefrontal areas. Furthermore, by using airjet as well as FG-7142, we now reveal that enhanced trait anxiety is also associated with neuronal hyperexcitability in the locus coeruleus and the periaqueductal gray, suggesting that investigation of an array of different anxiogenic stimuli is important for the detection of altered neuronal processing in trait anxiety.
Salchner
Peter
P
Department of Pharmacology and Toxicology, Institute of Pharmacy and Center of Molecular Biosciences Innsbruck, University of Innsbruck, Peter-Mayr-Strasse 1, A-6020 Innsbruck, Austria.
Sartori
Simone B
SB
Sinner
Catrin
C
Wigger
Alexandra
A
Frank
Elisabeth
E
Landgraf
Rainer
R
Singewald
Nicolas
N
D000388:Air; D000818:Animals; D001007:Anxiety / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D001522:Behavior, Animal; D001921:Brain / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D002243:Carbolines / Q000008:administration & dosage*; D004299:Dopamine beta-Hydroxylase / Q000378:metabolism; D004924:Escape Reaction / Q000187:drug effects; D018756:GABA Antagonists / Q000008:administration & dosage*; D015870:Gene Expression / Q000187:drug effects*; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D016761:Oncogene Proteins v-fos / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D018709:Statistics, Nonparametric
D002243:Carbolines; D018756:GABA Antagonists; D016761:Oncogene Proteins v-fos; C035874:FG 7142; D004299:Dopamine beta-Hydroxylase