Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New neuronal circuits which control fear have been identified

11.11.2010
Fear is an adaptive response, essential to the survival of many species. This behavioural adaptation may be innate but can also be a consequence of conditioning, during the course of which an animal learns that a particular stimulus precedes an unpleasant event.

There is a large amount of data indicating that the amygdala, a particular structure in the brain, is strongly involved during the learning of "conditioned" fear.

However, until now, the underlying neuronal circuits have remained largely unknown. Now, research involving several Swiss and German teams and a researcher from Inserm Unit 862, "Neurocentre Magendie", in Bordeaux, has been able to identify, for the first time, distinct neuronal circuits within the central nucleus of the amygdala which are specifically involved in acquisition and control of behavioural fear responses. Details of these results are published in this week's edition of the journal Nature.

In this study, laboratory mice were first subjected to a simple behavioural task which consisted of learning that an audible stimulus presaged the arrival of an unpleasant event. Following this conditioning, presentation of the audible stimulus induced a set of behavioural manifestations of fear such as freezing of the animals. Using highly innovative pharmacological and optogenetic techniques, the researchers have shown that the medial and central nuclei of the central amygdala were differentially involved in either learning or behavioural manifestation of fear responses (see the diagram on the next page). Indeed, the researchers were able to show that after inactivating the lateral subdivision of the central nucleus of the amygdala, the animals no longer learnt the association between the sound and the unpleasant event. By contrast, inactivation of the medial subdivision of this nucleus did not disrupt the learning of fear; however, the animals were now no longer able to give a behavioural manifestation to their fear, i.e. freezing.

In that second step, real-time recording of the activity of the neurons in the lateral and medial subdivisions of the central amygdala, using unique electrophysiological techniques, made it possible for the researchers to identify the specific neurons, within the structures, which were involved in conditioning and behavioural manifestation of fear responses.

These neurons are inhibitor cells belonging to very organized and strongly interconnected neuronal circuits. Modification of the activity of these circuits enables the relevant behavioural fear response to be selected as a function of the environmental situation.

Hence, our work defines the functional architecture of the neuronal circuits of the central amygdala and their role in acquisition and regulation of fear behaviours. Precise identification of the neuronal circuits which control fear is a major clinical challenge. Patients suffering from disorders, such as post-traumatic stress disorder or anxiety problems, exhibit disruption of certain neuronal circuits which leads to unsuitable anxiety behaviour responses. The selective manipulation of neuronal circuits that we have identified, using new therapeutic approaches which need to be developed further, could make it possible to regulate the pathological manifestations of fear in these patients.

Source
"Encoding of conditioned fear in central amygdala inhibitory circuits"
Stephane Ciocchi1*, Cyril Herry1*{, François Grenier1, Steffen B. E.Wolff1, Johannes J. Letzkus1, Ioannis Vlachos2, Ingrid Ehrlich1{,Rolf Sprengel3, Karl Deisseroth4, Michael B. Stadler1, Christian Müller1 & Andreas Lüthi1
1 Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland.
2 Bernstein Center for Computational Neuroscience, 79104 Freiburg, Germany.
3 Department of Molecular Neurobiology, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany.
4 Department of Bioengineering, Stanford University, Stanford, California 94305, USA.

Nature, 11 November 2010, DOI 10.1038/nature09559

Contact chercheur
Cyril Herry
Chargé de recherche Inserm
Unité Inserm 862,
Neurocentre Magendie
Bordeaux
Tel: +33 5 57 57 37 26
E-mail: cyril.herry@inserm.fr

Séverine Ciancia | EurekAlert!
Further information:
http://www.inserm.fr

More articles from Life Sciences:

nachricht Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View
22.06.2018 | University of Sussex

nachricht New cellular pathway helps explain how inflammation leads to artery disease
22.06.2018 | Cedars-Sinai Medical Center

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Upcycling of PET Bottles: New Ideas for Resource Cycles in Germany

25.06.2018 | Ecology, The Environment and Conservation

Graphene assembled film shows higher thermal conductivity than graphite film

22.06.2018 | Materials Sciences

Fast rising bedrock below West Antarctica reveals an extremely fluid Earth mantle

22.06.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>