Objectives: Enriched environment (EE) promotes functional recovery in animal models of stroke. Here, we used fMRI to assess temporal dynamics of brain recovery after stroke in rats, comparing different housing conditions. Methods: Transient brain ischemia (90 min) was induced in adult male Wistar rats. Groups of shamoperated rats were carried out in parallel for both housing conditions. Three weeks after stroke, animals were randomly distributed in either EE (n=11) or STD (n=12). EE consisted in large cages, with 2 levels, ramps, a running wheel, wooden blocks, among other items that were modified 2 times per week. Rats were studied for 12 weeks. MRI: T2 maps (7T, Bruker) were acquired to measure the lesion size. fMRI was performed every three weeks. Electrical forepaw stimulation was repeated 5 times (15sec each) with resting state periods in between (45sec each). Statistical activation maps were constructed with the software STIMULATE. Behavioral test: Cylinder test for asymmetries and Rotarod test for motor coordination were performed the day before each MRI session. Results None of the rats kept under STD showed signs of behavioural recovery, while EE significantly improved motor coordination and ameliorated motor asymmetries in relation to STD. In fMRI, 42% of the EE rats showed activity recovery (BOLD) between week 9 and 12, whereas this effect was not observed in any of the STD rats. Conclusion fMRI provides useful information of activated areas after forepaw stimulation. EE promotes the functional recovery of the original representation field, as assessed with fMRI and behavioural testing

Comunicación presentada en el IX Simposi de Neurobiologia Experimental, celebrado los días 22 y 23 de octubre de 2014 en Barcelona y organizado por la Societat Catalana de Biologia del Institut d'Estudis Catalans

Peer reviewed