Behavioural Brain Research 320 (2017) 58–66 Contents lists available at ScienceDirect Behavioural Brain Research journal homepage: www.elsevier.com/locate/bbr Research report Vibrissal paralysis produces increased corticosterone levels and impairment of spatial memory retrieval William E. Patarroyo a,b , Milady García-Perez a,b , Marisol Lamprea a,b , Alejandro Múnera a,c , Julieta Troncoso a,d,∗ a Behavioral Neurophysiology Laboratory, Universidad Nacional de Colombia, Bogotá, Colombia b Neurosciences Laboratory, Psychology Department, School of Human Sciences, Universidad Nacional de Colombia, Bogotá, Colombia c Physiological Sciences Department, School of Medicine, Universidad Nacional de Colombia, Bogotá, Colombia d Biology Department, School of Science, Universidad Nacional de Colombia, Bogotá, Colombia h i g h l i g h t s • Vibrissal paralysis was induced by bilateral facial nerve lesion in rats. • Injured and control rats were trained and tested in a spatial memory task. • Vibrissal paralysis induced retrieval but not acquisition impairment. • Corticosterone response to training or testing was higher in injured rats. • Paralysis-induced stress response potentiation may cause retrieval impairment. g r a p h i c a l a b s t r a c t a r t i c l e i n f o Article history: Received 19 August 2016 Received in revised form 22 November 2016 Accepted 28 November 2016 Available online 29 November 2016 Keywords: Vibrissae Rat Spatial memory Corticosterone Stress Barnes circular maze a b s t r a c t This research was aimed at establishing how the absence of active whisking in rats affects acquisition and recovery of spatial memory. The mystacial vibrissae were irreversibly paralyzed by cutting the facial nerve’s mandibular and buccal branches bilaterally in the facial nerve lesion group (N = 14); control ani- mals were submitted to sham-surgery (N = 15). Sham-operated (N = 11) and facial nerve-lesioned (N = 10) animals were trained (one session, eight acquisition trials) and tested 24 h later in a circular Barnes maze. It was found that facial nerve lesioned-animals adequately acquired the spatial task, but had impaired recovery of it when tested 24 h after training as compared to control ones. Plasma corticosterone levels were measured after memory testing in four randomly chosen animals of each trained group and after a single training trial in the maze in additional facial nerve-lesioned (N = 4) and sham-operated animals (N = 4). Significant differences respecting the elevation of corticosterone concentration after either a sin- gle training trial or memory testing indicated that stress response was enhanced in facial nerve-lesioned animals as compared to control ones. Increased corticosterone levels during training and testing might have elicited the observed whisker paralysis-induced spatial memory retrieval impairment. © 2016 Published by Elsevier B.V. Abbreviations: AHEF, all holes exploration frequency; BCM, Barnes circular maze; CORT, : corticosterone; HAB, habituation; HPA, hypothalamus-pituitary-adrenal; ROS, reactive oxygen species; SD, standard deviation; SEM, standard error of the mean; MWM, Morris water maze. ∗ Corresponding author at: Laboratorio de Neurofisiología Comportamental, Departamento de Biología, Universidad Nacional de Colombia, Edificio 421, Oficina 225, Carrera 30 No. 45-03, Ciudad Universitaria, 111321 Bogotá D.C., Colombia. E-mail address: jtroncoso@unal.edu.co (J. Troncoso). http://dx.doi.org/10.1016/j.bbr.2016.11.045 0166-4328/© 2016 Published by Elsevier B.V.