Environmental enrichment and recovery from a complex Go/No-Go reversal deficit in rats following large unilateral neocortical lesions

Postoperative environmental enrichment in brain-lesioned rats has been found to enhance performance in tasks in which a range of sensory cues can be utilized but not in tasks in which information from one particular sensory modality is essential to goal attainment. This has generally been construed as evidence of a role for environmental enrichment in facilitating compensation for sensory loss but not recovery of lost function per se. However, most published investigations have adopted an experimental design which fails to empirically separate the processes of recovery and compensation. The present investigation, by employing a unisensory task and using unilateral cortical lesions, thus markedly reducing the functional value of compensatory mechanisms in the mediation of postoperative behaviour, seeks to distinguish the contributions of these processes. The results show a sizeable hemidecorticate deficit on a visual operant Go/No-go reversal task but fail to provide clear evidence of any facilitation of functional recovery as a result of postoperative environmental enrichment.