Neurological and behavioral effects of intracranial administration of mercuric chloride on rats.

Mercuric chloride was injected intracranially into the rat brain in the region of the fourth ventricle via the foramen magnum. Responses to a single treatment of 0.3 mg/kg HgCl2, 0.03 mg/kg HgCl2, or carrier solution were followed for 10 days. Changes in the rats' behavior and motor coordination were observed 24-48 hr after treatment with HgCl2. Underwater swimming and decreased grooming and feeding were characteristic of mercury-treated rats. Decreased balancing ability and crossing of hind limbs suggested altered motor coordination. Rats treated with mercury often exhibited decreased body temperature, matting of fur about the eyes and perineal region, apparent visual impairment, decreased body weight, and diarrhea.