FEDERATION OF EUROPEAN NEUROSCIENCE SOCIETIES
9th FENS Forum of Neuroscience
5-9 July 2014 – Milan, Italy
http://fens2014.neurosciences.asso.fr/
PRESS RELEASE
EMBARGOED UNTIL WEDNESDAY 9 JULY 2014, 11:15 CEST / 10:15 BST
TRAUMA, PTSD, AND FEAR CIRCUITS IN THE BRAIN
Fear response helps us evade or escape danger. But extremely threatening or traumatic
situations — such as natural disasters, physical assault, military combat, or rape — can
generate profound fear-related brain patterns continuing long after, developing into posttraumatic stress disorder (PTSD) and other anxiety-related disorders. For these individuals,
exposure to a variety of cues — even in harmless environments —may trigger re-experiencing
the original trauma. Scientists in France are using cutting-edge research techniques, including
optogenetics, to identify brain mechanisms underpinning trauma-induced fear expression.
A research team at the Inserm Magendie Neurocentre in Bordeaux, led by Dr Cyril Herry, have
been investigating what happens in the brain during various types of fear behaviour. Speaking
today (9 July) in Milan, Dr Herry described innovative research in mice — using behavioural
analysis, electrophysiological recording, and optogenetics techniques — to unravel the brain
structures and mechanisms underlying fear response.
Dr Herry and his team at Inserm Magendie Neurocentre, a research centre of the French
National Institute of Health and Medical Research (INSERM), examine connections between fear
behaviour and emotional memory. "We use a novel behavioural fear paradigm that captures
many clinical features of PTSD," he noted. His laboratory is one of the few which record
neuronal activity in live, behaving animals, while also utilising state-of-the-art optogenetic
techniques.
Research by Dr Herry and colleagues is clarifying that an area of the forebrain — the medial
prefrontal cortex — is crucial to the expression of conditioned fear behaviour in mice. Previous
studies by Dr Herry's team investigating this brain area uncovered detailed cellular mechanisms
underlying fear memory, response, and behaviour. Using optogenetics, they identified and
examined specific brain circuits involved. A more recent study revealed that inhibition of specific
neurons in a particular area of the prefrontal cortex are key in fear response. Utilising various
methods including optogenetics, they investigated this unique chain reaction, in which inhibition
of some cells activates other cells and brain areas, reactivating fear expression in individuals.
One PTSD hallmark is "fear generalisation" — re-experiencing fear response in a nonthreatening environment. For many people, this continued response to nonthreatening cues
affects their lives deeply. Dr Herry's ongoing studies in mice are the first to analyse brain
activity during context-induced fear generalisation; as well as in fear discrimination, when one
no longer responds with fear generalisation in those nonthreatening contexts. Examining brain
activity as mice discriminate between threatening and non-threatening environments, "we hope
to identify brain mechanisms of fear generalisation and discrimination behaviours, and
understand the neuronal circuits responsible," he said.
Across these studies, Dr Herry's research team records behaviour and brain activity in live
animals, as well as utilising optogenetic methods. Optogenetics, an increasingly popular
research technique, uses light to induce brain cell activity. Simulating brain impulses using light,
scientists can precisely examine and manipulate how brain circuits electrically communicate —
in living animals, in real-time. “Studying fear behaviour in mice, optogenetic technology allows
us to activate neurons in specific brain areas, with unprecedented millisecond temporal
precision; and to turn specific brain cell types and pathways on or off," noted Dr Herry.
"Combining these techniques, we are better able to examine how fear response manifests in the
brain, and to clarify which circuits might generate it."
Dr Herry hopes that by more deeply understanding brain mechanisms behind the fear-related
behaviours characteristic of PTSD, they might advance research in humans facing these
conditions. "Our continuing animal studies identifying detailed neuronal activity may offer vital
insights on fear processing in the human brain, facilitating development of new treatments for
PTSD and related psychiatric conditions."
END
Abstract Reference R10044: Prefrontal neuronal mechanisms of fear generalization
Symposia S53: Generalization of emotional memories: from neural circuits to anxiety disorders
Contact
FENS Press Office and all media enquiries:
Elaine Snell, Snell Communications Ltd, London UK (English language)
tel: +44 (0)20 7738 0424 or mobile +44 (0)7973 953 794
email: Elaine@snell-communications.net
Mauro Scanu (Italian language)
tel: +39 333 161 5477
email: press.office@fens.org
Dr Cyril Herry cyril.herry@inserm.fr
NOTES TO EDITORS
The 9th FENS Forum of Neuroscience, the largest basic neuroscience meeting in Europe,
organised by FENS and hosted by the The Società Italiana di Neuroscienze (SINS) (Italian
Society for Neuroscience) will attract an estimated 5,500 international delegates. The
Federation of European Neuroscience Societies (FENS), founded in 1998, aims to advance
research and education in neuroscience, representing neuroscience research in the European
Commission and other granting bodies. FENS represents 42 national and mono-disciplinary
neuroscience societies with close to 23,000 member scientists from 32 European countries.
http://fens2014.neurosciences.asso.fr/
Further Reading (Herry)
Prefrontal parvalbumin interneurons shape neuronal activity to drive fear expression. J Courtin ,
F Chaudun, RR Rozeske, N Karalis, C Gonzalez-Campo, H Wurtz, A Abdi, J Baufreton, TC
Bienvenu, C Herry. Nature. January 2014; 505 (7481 ): 92-6.
DOI: 10.1038/nature12755
Medial prefrontal cortex neuronal circuits in fear behavior. J Courtin, TCM Bienvenu, EÖ
Einarsson, C Herry . Neuroscience. 2013, Vol 240: 219-242.
DOI: 10.1016/j.neuroscience.2013.03.001