A rodent model for investigating the neurobiology of contralateral neglect

Abstract

Background: Contralateral neglect is a common and disabling sequela of right hemisphere strokes. Neglect involves attentional and cognitive deficits, including distortions of contralateral spatial and personal awareness. There are no established successful therapies for neglect, and treatment is often complicated by anosognosia. The disturbances associated with neglect are debilitating to patients and their families, and presence of neglect is a strong predictor of poor prognosis for recovery.

Objective: The present report reviews findings from 20 years of research using a rat model of neglect. In the rat, 2 cortical areas that are linked by corticocortical connections have been identified as having a major role in neglect, and these correspond to frontal and parietal fields in primates. These 2 cortical areas also have convergent projections to the dorsocentral striatum, which has been implicated as a crucial subcortical component of the cortical-striatal-thalamic circuitry involved in directed attention and neglect. We discuss the role of the dorsocentral striatum in neglect and recovery and present evidence that induced axonal sprouting may promote functional recovery following cortical lesions that produce neglect.

Conclusions: The rodent model of neglect captures some of the essential behavioral and anatomic features of neglect in humans. This model has helped reveal the pathophysiology of neglect, has suggested a crucial role of the striatum in recovery from neglect, and is being used to investigate potential therapeutic approaches.