title: Importance of schedule of exposure to hexane in causing neurotoxicity.
abstract: Male Fischer rats exposed continuously (24 hr per day) to 1,000 ppm hexane five days per week for 11 weeks developed clear and long-lasting neurotoxic signs, as reflected by a marked decrease in hind-limb grip strength and severe impairment of performance of a multisensory conditioned avoidance response (CAR); transient decreases in undifferentiated motor activity and fore-limb grip strength were also seen. Other rats were only slightly affected by repeated, brief (10 min) exposures to high concentrations (24,000 or 48,000 ppm) of hexane 6 or 12 times per day, five days per week for 18 weeks; when the frequency of exposure to 48,000 ppm hexane was increased to 24 times per day (10 min on and 5 min off), five days per week, for 4 additional weeks, more severe signs of neurobehavioral toxicity appeared.
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D001522:Behavior, Animal / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D003213:Conditioning, Psychological / Q000187:drug effects; D006586:Hexanes / Q000633:toxicity*; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009048:Motor Skills / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D009410:Nerve Degeneration / Q000187:drug effects; D009420:Nervous System / Q000187:drug effects*; D051381:Rats; D011916:Rats, Inbred F344; D012584:Sciatic Nerve / Q000187:drug effects
chemical_list: D006586:Hexanes