The neurotoxicity of Penitrem A (PA) in rats was assessed against neurophysiological, behavioral and histopathological parameters. Animals were acutely given intracerebroventricular (22-45 mg) or intraperitoneal injections (0.5-1.5 mg/kg) of PA. A typical trembling syndrome associated with PA was always noted. Depending on the dose administered, animals may convulse and eventually die (1-1.5mg/kg). PA-induced transient alterations of the EEG involving an increase in the frequency and voltage of electrical activity recorded from the cerebral cortex. Hippocampal activity was not modified and some pathologic activities may be recorded at the thalamus. Generally these EEG alterations disappeared at d3 after the injection and the animals progressively recovered. However in the Inost severe cases, neuromotor disturbances were maintained at d7 (rotarod test). Coronal sections of the brain at the striatal, thalamic, hippocampal and pens levels mainly revealed that PA was able to induce dose related injuries in the cerebellum with massive degeneration of Purkinje cells and a significant vacuolization within the molecular layer. The neurotoxic mechanism remains unclear. Action of the mycotoxin on the cerebello-thalamo-cortical tract is discussed. (C) 1998 Elsevier Science Ltd. All rights reserved.