TY - JOUR
T1 - Locomotor activity changes following lipopolysaccharide treatment in mice
T2 - A multivariate assessment of behavioral tolerance
AU - Engeland, Christopher G.
AU - Nielsen, Daniel V.
AU - Kavaliers, Martin
AU - Ossenkopp, Klaus Peter
N1 - Funding Information:
This research was supported by operating grants from the Natural Sciences and Engineering Research Council of Canada to Martin Kavaliers and Klaus-Peter Ossenkopp. It was also made possible by equipment and software support from Accuscan. Christopher Engeland was supported by an Ontario Graduate Scholarship.
PY - 2001
Y1 - 2001
N2 - To determine the effects of repeated, acute endotoxin exposure on locomotor behavior, male laboratory mice were injected intraperitoneally with lipopolysaccharide (LPS: 50, 100 or 200 μg/kg) or saline vehicle on experimental Days 1, 4 and 7. At 2 h after each treatment, locomotor activity was assessed in a nonnovel, automated open-field apparatus (Digiscan) for 30 min. On Day 1, all horizontal and vertical activity measures were significantly reduced to near zero values by each dose of LPS. Behavioral tolerance to LPS formed rapidly, as locomotor activity of the treated groups did not differ from the control group on Days 4 or 7. In a second study, mice were given LPS (50, 100 or 150 μg/kg ip) or saline vehicle on two test days, 28 days apart. Activity was assessed, 1 h after injection, in a novel open field on the first test day and in a nonnovel open field on the second test day. Significant locomotor activity decrements were readily apparent in LPS-treated mice only in the nonnovel open field. This latter finding indicates that environmental novelty mediates, at least partially, the locomotor-reducing effects of LPS in mice.
AB - To determine the effects of repeated, acute endotoxin exposure on locomotor behavior, male laboratory mice were injected intraperitoneally with lipopolysaccharide (LPS: 50, 100 or 200 μg/kg) or saline vehicle on experimental Days 1, 4 and 7. At 2 h after each treatment, locomotor activity was assessed in a nonnovel, automated open-field apparatus (Digiscan) for 30 min. On Day 1, all horizontal and vertical activity measures were significantly reduced to near zero values by each dose of LPS. Behavioral tolerance to LPS formed rapidly, as locomotor activity of the treated groups did not differ from the control group on Days 4 or 7. In a second study, mice were given LPS (50, 100 or 150 μg/kg ip) or saline vehicle on two test days, 28 days apart. Activity was assessed, 1 h after injection, in a novel open field on the first test day and in a nonnovel open field on the second test day. Significant locomotor activity decrements were readily apparent in LPS-treated mice only in the nonnovel open field. This latter finding indicates that environmental novelty mediates, at least partially, the locomotor-reducing effects of LPS in mice.
UR - http://www.scopus.com/inward/record.url?scp=0035088014&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035088014&partnerID=8YFLogxK
U2 - 10.1016/S0031-9384(00)00436-4
DO - 10.1016/S0031-9384(00)00436-4
M3 - Article
C2 - 11282131
AN - SCOPUS:0035088014
SN - 0031-9384
VL - 72
SP - 481
EP - 491
JO - Physiology and Behavior
JF - Physiology and Behavior
IS - 4
ER -