TY - JOUR
T1 - Scheduled access to ethanol results in motor impairment and tolerance in female C57BL/6J mice
AU - Cronise, K.
AU - Finn, D. A.
AU - Metten, P.
AU - Crabbe, J. C.
N1 - Funding Information:
Supported by NIAAA INIA Consortium grants AA13478 and AA13519, Portland Alcohol Research Center grant AA10760, and the Department of Veterans Affairs. K. Cronise was supported by NIAAA training grant AA07468. We gratefully acknowledge the technical assistance of Karyn Best, Andy Cameron and Christina Cotnam.
PY - 2005/8
Y1 - 2005/8
N2 - We recently reported a method where water-restricted mice were given scheduled access to ethanol followed by access to water. C57BL/6J mice would repeatedly self-administer ethanol in amounts that produced high and stable blood ethanol concentrations (BEC) [Finn DA, Belknap JK, Cronise K, Yoneyama N, Murillo A, Crabbe JC. A procedure to produce high alcohol intake in mice. Psychopharmacol 2005;178:471-480]. The studies reported here demonstrate that behavioral signs of motor impairment result from these high alcohol intakes, and that there was some evidence of tolerance development across repeated sessions. Female C57BL/6J mice were allowed 30 min access to ethanol (5% v/v) followed by 2.5 h access to water either: every 3rd day for 12 days; every 2nd day for 28 days; or every 2nd day for 9 days. On intervening days, mice had 3 h access to water. A control group had daily access to water only. Mice consumed 2-2.5 g/kg ethanol in 30 min, resulting in BECs of 1.4-1.5 mg/ml. Motor impairment was assessed using the accelerating or fixed speed rotarod, balance beam or screen test. In all studies, mice were tested for motor impairment immediately after 30 min access to ethanol or water. In Experiment 1, ethanol-exposed mice had shorter latencies to fall from the fixed speed rotarod and more foot slips on the balance beam than the control group, indicating motor impairment. After drinking ethanol, mice also fell from a screen more quickly than during sober pretraining. In Experiment 2, mice tested (without prior training) for motor impairment and tolerance on the fixed speed rotarod at 6.5 and 10 RPM showed repeated motor impairment in the ethanol group, but did not develop tolerance. In Experiment 3, mice were first given rotarod training at 10 RPM. Following each fluid access period, performance was impaired in mice self-administering ethanol at 10, but not 15 RPM, when compared to control mice. There was no evidence of tolerance across days. However, on the last day, all mice were tested at both RPM following an i.p. injection of 2 g/kg ethanol. Ethanol-experienced mice were less impaired at both RPM than the ethanol-naïve mice, indicating tolerance development according to this between-groups index. These results suggest that C57BL/6J mice will repeatedly consume alcohol in amounts that produce motor impairment under these scheduled fluid access conditions, and that a modest degree of tolerance can be detected using appropriate tests.
AB - We recently reported a method where water-restricted mice were given scheduled access to ethanol followed by access to water. C57BL/6J mice would repeatedly self-administer ethanol in amounts that produced high and stable blood ethanol concentrations (BEC) [Finn DA, Belknap JK, Cronise K, Yoneyama N, Murillo A, Crabbe JC. A procedure to produce high alcohol intake in mice. Psychopharmacol 2005;178:471-480]. The studies reported here demonstrate that behavioral signs of motor impairment result from these high alcohol intakes, and that there was some evidence of tolerance development across repeated sessions. Female C57BL/6J mice were allowed 30 min access to ethanol (5% v/v) followed by 2.5 h access to water either: every 3rd day for 12 days; every 2nd day for 28 days; or every 2nd day for 9 days. On intervening days, mice had 3 h access to water. A control group had daily access to water only. Mice consumed 2-2.5 g/kg ethanol in 30 min, resulting in BECs of 1.4-1.5 mg/ml. Motor impairment was assessed using the accelerating or fixed speed rotarod, balance beam or screen test. In all studies, mice were tested for motor impairment immediately after 30 min access to ethanol or water. In Experiment 1, ethanol-exposed mice had shorter latencies to fall from the fixed speed rotarod and more foot slips on the balance beam than the control group, indicating motor impairment. After drinking ethanol, mice also fell from a screen more quickly than during sober pretraining. In Experiment 2, mice tested (without prior training) for motor impairment and tolerance on the fixed speed rotarod at 6.5 and 10 RPM showed repeated motor impairment in the ethanol group, but did not develop tolerance. In Experiment 3, mice were first given rotarod training at 10 RPM. Following each fluid access period, performance was impaired in mice self-administering ethanol at 10, but not 15 RPM, when compared to control mice. There was no evidence of tolerance across days. However, on the last day, all mice were tested at both RPM following an i.p. injection of 2 g/kg ethanol. Ethanol-experienced mice were less impaired at both RPM than the ethanol-naïve mice, indicating tolerance development according to this between-groups index. These results suggest that C57BL/6J mice will repeatedly consume alcohol in amounts that produce motor impairment under these scheduled fluid access conditions, and that a modest degree of tolerance can be detected using appropriate tests.
KW - Alcohol
KW - Consumption
KW - Intoxication
KW - Motor incoordination
KW - Mouse
KW - Rotarod
KW - Self-administration
KW - Tolerance
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U2 - 10.1016/j.pbb.2005.07.005
DO - 10.1016/j.pbb.2005.07.005
M3 - Article
C2 - 16099022
AN - SCOPUS:23944501980
SN - 0091-3057
VL - 81
SP - 943
EP - 953
JO - Pharmacology Biochemistry and Behavior
JF - Pharmacology Biochemistry and Behavior
IS - 4
ER -