Strain differences in recovery from sensorimotor neglect after unilateral globus pallidus lesions in mice

Recovery of somatosensory orientation after unilateral electrolytic lesions of globus pallidus was studied in two inbred strains of mice (C57BL/6, Sec 1/ReJ). During the first four post-lesion days mice of both strains did not react to tactile stimuli (von Frey hair of 2 g intensity) applied to the thorax area contralateral to the lesion. Successively, there was a gradual replacement by non-oriented activation and incomplete oriented responses, followed by normal precise orientation. Recovery of orientation proceeded at a significantly higher rate in C57 mice. After a period of four months C57 mice reached a recovery level of 91% in comparison to 56% of Sec mice. The genotype dependent differences of recovery mechanisms are discussed in terms of plasticity and dopaminergic systems.