Imparied maze performance in the rat caused by trimethyltin treatment: problem-solving deficits and perseveration

Trimethyltin (TMT) produces cytological damage to several limbic-forebrain structures which is accompanied by behavioral changes including hyperactivity and aggressiveness. The purpose of this investigation was to determine whether the problem-solving capacity of the rat is affected by TMT treatment. Either 7.0 mg/kg of TMT ([CH3]3SnCl) or 0.9% saline was injected by gavage into the gastric lumen of each rat. The treated and non-treated animals were divided into two groups of nine each and tested subsequently on a series of Hebb-Williams maze problems. In comparison to the controls, the tin-treated rats made markedly more errors on all but one of the maze patterns. Moreover, the rate of error reduction across problems over the 10 daily trials was significantly retarded in the lesioned animals. In addition to these severe problem-solving deficits, the TMT-treated rat often exhibited a characteristic pattern of perseverative behavior while running in the maze. The pattern was not unlike stereotypies associated with the psychomotor pathology observed following treatment with certain drugs. Overall, the results of the performance of the animal in the Hebb-Williams task provides a corollary with the child afflicted with minimal brain dysfunction (MBD) and, thus, a model for MBD is suggested.