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Ann N Y Acad Sci

Title:		Repeated formaldehyde effects in an animal model for multiple chemical sensitivity
Author(s):		Sorg BA; Tschirgi ML; Swindell S; Chen L; Fang J;
Address:		"Program in Neuroscience, Department of VCAPP, Washington State University, Pullman 99164-6520, USA. barbsorg@vetmed.wsu.edu"
Journal Title:		Ann N Y Acad Sci
Year:		2001
Volume:		933
Issue:
Page Number:		57 - 67
DOI:		10.1111/j.1749-6632.2001.tb05814.x
ISSN/ISBN:		0077-8923 (Print) 0077-8923 (Linking)
Abstract:		"Chemical intolerance is a phenomenon observed in multiple chemical sensitivity (MCS) syndrome, an ill-defined disorder in humans attributed to exposure to volatile organic compounds. Amplification of symptoms in individuals with MCS resembles the phenomenon of psychostimulant- and stress-induced sensitization in rodents. We have recently tested in rats the hypothesis that repeated chemical exposure produces sensitization of central nervous system (CNS) circuitry. A rat model of MCS in our laboratory has employed several endpoints of CNS function after repeated formaldehyde (Form) exposure (1 h/day x 5 days/week x 4 weeks). Repeated Form exposure produced behavioral sensitization to later cocaine injection, suggesting altered dopaminergic sensitivity in mesolimbic pathways. Rats given repeated Form also demonstrated increased fear conditioning to odor paired with footshock, implicating amplification of neural circuitry guiding fear responding to a conditioned odor cue. Recent studies examining the effects of repeated Form on locomotor activity during each daily exposure showed a decrease in rearing activity after 12-15 days of Form exposure compared to air-exposed controls. EEG recordings taken 1 week after withdrawal from daily Form revealed altered sleep architecture. Some of the differences in sleep disappeared after subsequent brief (15 min) challenge with Form the next day. Overall, the findings indicate that repeated low-level chemical exposure produces behavioral changes that may be akin to those observed in individuals with MCS, such as greater sensitivity to chemicals manifest as increased anxiety upon chemical exposure and altered sleep and/or fatigue. Study of the underlying CNS changes will provide a basis for mechanistically based animal models for MCS"
Keywords:		"Animals Avoidance Learning Behavior, Animal/drug effects Brain/drug effects/physiopathology Central Nervous System Stimulants/administration & dosage/pharmacology/toxicity Cocaine/administration & dosage/pharmacology/toxicity Conditioning, Classical Dopam;Neuroscience;"
Notes:		"MedlineSorg, B A Tschirgi, M L Swindell, S Chen, L Fang, J eng DA 11787/DA/NIDA NIH HHS/ ES 09135/ES/NIEHS NIH HHS/ Research Support, U.S. Gov't, P.H.S. Review 2002/05/10 Ann N Y Acad Sci. 2001 Mar; 933:57-67. doi: 10.1111/j.1749-6632.2001.tb05814.x"