Scientists Identify Genetic Markers of Fear

An international team of researchers leaded by the Universitat Autònoma de Barcelona have found experimental evidence that the various manifestations of fear in animals are influenced by a specific place or region within the genome. The results, published in the latest edition of Genome Research, were obtained with rats, but the scientists suspect that this research will facilitate an understanding of genetic characteristics and conditioning factors related to fear in humans.

Demonstrating that a gene influences susceptibility to fear involves the need to determine the connection between the gene’s activity and a range of various behavioural and manifestation forms pertaining to this activity. To date, however, studies carried out in this area have only been able to establish a link between genetic charge and a few isolated tendencies related to fear.

Now and for the first time, an international team of scientists lead by researchers at the Medical Psychology Unit (Department of Psychiatry and Legal Medicine) at the Universitat Autònoma de Barcelona have detected the influence of a specific place (locus) within the rat genome, a unique region (QTL) located in chromosome 5, in various manifestations of fear assessed under different experimental conditions. In the study, the rats were submitted to new and unknown experiences and were obliged to cope with open spaces and heights, along with other situations of conditioned fear. That is, they were faced with the signals that warn of something disagreeable or frightening about to happen. The study is therefore an initial multi-variant analysis that explores the genetic basis to manifestations of fear in an animal, bearing in mind a range of fear-conduct models. Furthermore, it was carried out on a large sample of endogamous offspring of both timorous and daring rats.

For Alberto Fernández-Teruel, the principal author of the study published in the April edition of Genome Resarch, “the fact that the neurone and nerve mechanisms of fear are common in all vertebrates heightens the relevance of having discovered the localisation for a genetic locus in rat chromosome 5 that is related to fear, and lends greater pertinence to the study of the genetic characteristics and conditioning factors of fear and anxiety in humans; very probably, there is one specific gene (or several) in chromosome 5 that influences the behaviour of fear in rats, and the identification of the counterparts in humans would lead to a greater understanding both of the bases of fear in people and of anomalies related with fear in human conduct”.

In addition to the importance of the discovery with respect to the genetic bases of fear, the research provides evidence, for the first time, for the way in which the activity of a specific genome locus manifests itself in animal conduct through a whole pattern of inter-connected effects.

Scientists from the Universitat Autònoma de Barcelona who participated in the research were Alberto Fernández-Teruel, Rosa M. Escorihuela, Raúl Aguilar, Luis Gil, Lydia Giménez-Llort and Adolf Tobeña. They worked together with researchers from the Institute of Psychiatry in London (Jeffrey A. Gray); from the Wellcome Trust Centre for Human Genetics in Oxford (Jonathan Flint, Amarjit Bhomra, Alison Nicod, Richard Mott); from the Institut Nutztierwissenschaften Eidgnössische Technische Hochschule in Zurich (Peter Driscoll); and from the Merck Sharp and Dhome Research Laboratories at the Neuroscience Research Centre in Essex, England (Gerard R. Dawson).