Antonio Florido1,2, Laura Perez-Caballero1,2, Eric Raúl Velasco1, Patricia Molina1,3, Ignacio Marin-Blasco1, Raül Andero1,2,4,5,6. 1. Institut de Neurociències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain. 2. Departament de Psicobiologia i de Metodologia de les Ciències de la Salut, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain. 3. Unitat de Fisiologia Animal (Departament de Biologia Cel·lular, Fisiologia i Immunologia), Facultat de Biociències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, Spain. 4. Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Instituto de Salud Carlos III, Madrid, Spain. 5. Unitat de Neurociència Traslacional, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí (I3PT), Institut de Neurociències, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain. 6. ICREA, Barcelona, Spain.
Abstract
Fear conditioning (FC) is a widely accepted tool for the assessment of learning and memory processes in rodents related to normal and dysregulated acquired fear. The study of sex differences in fear learning and memory is vast and currently increasing. Sex hormones have proven to be crucial for fear memory formation in males and females, and several methods have been developed to assess this hormonal state in rats and mice. Herein, we explain a routine FC and extinction protocol, together with the evaluation of sex hormonal state in male and female rodents. We explain three protocols for the evaluation of this hormonal state directly from blood samples extracted during the procedure or indirectly through histological verification of the estrous cycle for females or behavioral assessment of social hierarchies in males. Although females have typically been considered to present great variability in sex hormones, it is highlighted that sex hormone assessment in males is as variable as in females and equally important for fear memory formation. The readout of these protocols has had a great impact on different fields of fear learning and memory study and appears essential when studying FC. The proven interaction with drugs involved in the modulation of these processes makes sex hormone assessment during FC a valuable tool for the development of effective treatments for fear-related disorders in men and women.
Fear conditioning (FC) is a widely accepted tool for the assessment of learning and memory processes in rodents related to normal and dysregulated acquired fear. The study of sex differences in fear learning and memory is vast and currently increasing. Sex hormones have proven to be crucial for fear memory formation in males and females, and several methods have been developed to assess this hormonal state in rats and mice. Herein, we explain a routine FC and extinction protocol, together with the evaluation of sex hormonal state in male and female rodents. We explain three protocols for the evaluation of this hormonal state directly from blood samples extracted during the procedure or indirectly through histological verification of the estrous cycle for females or behavioral assessment of social hierarchies in males. Although females have typically been considered to present great variability in sex hormones, it is highlighted that sex hormone assessment in males is as variable as in females and equally important for fear memory formation. The readout of these protocols has had a great impact on different fields of fear learning and memory study and appears essential when studying FC. The proven interaction with drugs involved in the modulation of these processes makes sex hormone assessment during FC a valuable tool for the development of effective treatments for fear-related disorders in men and women.
Authors: E R Velasco; A Florido; Á Flores; E Senabre; A Gomez-Gomez; A Torres; A Roca; S Norrholm; E L Newman; P Das; R A Ross; A Lori; O J Pozo; K J Ressler; L L Garcia-Esteve; T Jovanovic; R Andero Journal: Nat Commun Date: 2022-07-28 Impact factor: 17.694