Environmental enrichment and cerebrolysin improve motor and cognitive performance in a rat model of stroke, in conjunction with an increase in hippocampal AMPA but not NMDA receptor subunits

Abstract

Stroke is a pathology related to the vascular system in the brain and it is one of the main causes of disability, representing a burden on public health. This lesion provokes a disorganization of sensory-motor and cognitive systems, the latter associated with hippocampal activity, a structure in which α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and NMDA N-methyl-D-aspartate (NMDA) receptors are important for the integration of information. Several molecules have been studied for their capacity to enhance recovery from a stroke, including cerebrolysin that could potentially be reinforced by environmental enrichment. Here, stroke was induced in 40 male rats and 24 h later, they were administered cerebrolysin (2.5 ml/kg), put in an environmentally enriched arena or given both treatments, for 10 days. Subsequently, motor functioning was assessed with the Bederson test and the cognitive domain was assessed through novel object recognition. Hematoxylin/eosin staining was then used to assess the infarct size, and AMPA-GRIA1 and NMDA-R1 subunits in the hippocampus were measured by ELISA. In motor and cognitive performance, the administration of cerebrolysin and environmental enrichment enhanced recovery. Moreover, the infarct size decreased in all the groups that received a treatment, but an increase occurred in AMPA-GRIA1 only in experimental group regarding to control group, while NMDA-R1 had no differences. These results suggest that cerebrolysin and environmental enrichment could act in synergy to recover after a stroke, leading to a smaller infarct area and the presence of more AMPA-GRIA1 subunits in the hippocampus of experimental group. These data encourage further studies in which neurorehabilitation approaches can be combined with cerebrolysin administration to treat the motor and cognitive symptoms of stroke.