Delayed restraint procedure enhances cognitive recovery of spatial function after fimbria-fornix transection

Article type: Research Article

Authors: Gram, Marie Gajhede^a | Wogensen, Elise^{a; 1} | Wörtwein, Gitta^b | Mogensen, Jesper^{a; *} | Malá, Hana^a

Affiliations: [a] The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Copenhagen, Denmark | [b] Laboratory of Neuropsychiatry, Department of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark

Correspondence: [*] Corresponding author: Jesper Mogensen, The Unit for Cognitive Neuroscience, Department of Psychology, University of Copenhagen, Oester Farimagsgade 2A, DK-1353, Copenhagen K, Denmark. Tel.: +45 35324873; Fax: +45 35324802; E-mail: [email protected].

Note: [1] Present address Elise Wogensen: Kommunikationscenteret, The Capital Region of Denmark.

Abstract: Purpose:To i) evaluate the effect of a restraint procedure (7 days, 2 h/day) on place learning after fimbria-fornix transection (FF), ii) investigate effects of early vs. late administration of restraint, and iii) establish effects of the restraint procedure on expression of brain derived neurotrophic factor (BDNF) in prefrontal cortex and hippocampus. Methods:Fifty rats subjected to FF or sham surgery and divided into groups exposed to restraint immediately (early restraint) or 21 days (late restraint) after surgery were trained to acquire an allocentric place learning task. In parallel, 29 animals were subjected to FF or sham surgery and an identical restraint procedure in order to measure concentrations of BDNF and corticosterone. Results:The performance of the sham operated rats was positively affected by the late restraint. In FF-lesioned animals, the late restraint significantly improved task performance compared to the lesioned group with no restraint, while the early restraint was associated with a negative impact on task acquisition. Biochemical analysis after restraint procedure revealed a lesion-induced upregulation of BDNF in FF animals. Conclusions:The improved task performance of lesioned animals suggests a therapeutic effect of this manipulation, independent of BDNF. This effect is sensitive to the temporal administration of treatment.

Keywords: Brain injury, restraint procedure, rat, functional recovery, time

DOI: 10.3233/RNN-140396

Journal: Restorative Neurology and Neuroscience, vol. 34, no. 1, pp. 1-17, 2016