Anxiety in genetically heterogeneous rats: Towards the identification of quantitative genes for behavioural traits by López-Aumatel, R, Vicens-Costa, E, Guitart-Masip, M, Martínez-Membrives, E, Valda, W, Johannesson, M, Cañete, T, Blázquez, G, Giménez-Llort, L, Flint, J, Tobeña, A, Fernández-Teruel, A