Citation

Kawa L, Arborelius U, Yoshitake T, Kehr J, Hökfelt T, Risling M, Agoston DV. J. Neurotrauma 2014; 32(16): 1190-1199.

Affiliation

Karolinska Institutet, Department of Neuroscience, Stockholm, Sweden ; Lizan.Kawa@ki.se.

Copyright

(Copyright © 2014, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2014.3669

PMID

25525686

Abstract

Exposure to improvised explosive devices can result in a unique form of traumatic brain injury, blast-induced traumatic brain injury (bTBI). At the mild end of the spectrum (mild bTBI, mbTBI) there are cognitive and mood disturbances. Similar symptoms have been observed in post-traumatic stress disorder caused by exposure to extreme psychological stress without physical injury. The role of the monoaminergic system in mood regulation and stress is well established, but its role in mbTBI is not well understood. To address this gap, we used a rodent model of mbTBI and detected a decrease in immobility behaviour in the forced swim test at one day post-exposure, coupled with an increase in climbing behaviour, but not after 14 d or later, possibly indicating a transient increase in anxiety-like behaviour. Using in situ hybridisation, we found elevated mRNA levels of both tyrosine hydroxylase and tryptophan hydroxylase 2 in the locus coeruleus and the dorsal raphe nucleus, respectively, as early as 2 h post-exposure. HPLC analysis one day post-exposure primarily showed elevated noradrenaline levels in several forebrain regions. Taken together, we report that exposure to mild blast results in transient changes in both anxiety-like behaviour and brain region-specific molecular changes implicating the monoaminergic system in the pathobiology of mbTBI.

Language: en