Research Report Delayed intensive acquisition training alleviates the lesion- induced place learning deficits after fimbria–fornix transection in the rat Hana Malá, María Rodríguez Castro, Hadley Pearce, Siff Camilla Kingod, Signe Kjær Nedergaard, Zakaryiah Scharff, Maja Zandersen, Jesper Mogensen ⁎ The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Denmark ARTICLE INFO ABSTRACT Article history: Accepted 14 January 2012 Available online 24 January 2012 This study evaluates the effects of two learning paradigms, intensive vs. baseline, on the posttraumatic acquisition of a water maze based place learning task. Rats were subjected either to a control operation (Sham) or to a fimbria–fornix (FF) transection, which renders the hippocampus dysfunctional and disrupts the acquisition of allocentric place learning. All animals were administered 30 post-lesion acquisition sessions, which spanned either 10 or 30 days. The acquisition period was followed by a 7 day pause after which a retention probe was administered. The lesioned animals were divided into 3 groups: i) Baseline Acquisition Paradigm (BAP) once daily for 30 days starting 1 week post-surgery; ii) Early Intensive Acquisition Paradigm (EIAP) 3 times daily for 10 days starting 1 week post-surgery; and iii) Late Intensive Acquisition Paradigm (LIAP) 3 times daily for 10 days starting 3 weeks post- surgery. Within the control animals, one group followed the schedule of BAP, and one group followed the schedule of Intensive Acquisition Paradigm (IAP). All lesioned animals showed an impaired task acquisition. LIAP was beneficial in FF animals, in that it led to a better acqui- sition of the place learning task than the two other acquisition paradigms. The FF/EIAP group did not show improved acquisition compared to the FF/BAP group. The control animals were not differentially affected by the two learning schedules. The findings have implications for cognitive rehabilitation after brain injury and support the assumption that intensive treatment can lead to an improved learning, even when the neural structures underlying such a process are compromised. However, the timing of intensive treatment needs to be considered further. © 2012 Elsevier B.V. All rights reserved. Keywords: Neurotrauma Functional recovery Place learning Intensive training Fimbria–fornix Rat 1. Introduction Neuroplasticity refers to the lifelong ability of the brain to reorganize its neural circuitry in response to experience, exercise, and stimulation. Learning and acquisition of new knowledge and skills likewise continuously modulate the communication between neurons and shape neural pathways. Besides playing an essential role during normal development, BRAIN RESEARCH 1445 (2012) 40 – 51 ⁎ Corresponding author at: The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Oester Farimags- gade 2A, DK-1353 Copenhagen K, Denmark. Fax: + 45 35324802. E-mail address: jesper.mogensen@psy.ku.dk (J. Mogensen). Abbreviations: FF, fimbria–fornix; BAP, Baseline Acquisition Paradigm; IAP, Intensive Acquisition Paradigm; EIAP, Early Intensive Acquisition Paradigm; LIAP, Late Intensive Acquisition Paradigm 0006-8993/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.brainres.2012.01.035 Available online at www.sciencedirect.com www.elsevier.com/locate/brainres