Chronic Nicotine Treatment with Locomotor and Temperature Monitoring
Objective: To assess tolerance development to acute nicotine effects on locomotor activity and body temperature following chronic nicotine treatment, and to measure changes in nicotinic receptor binding and mRNA expression in brain regions
Protocol Steps
Chronic nicotine administration
DBA mice received continuous intravenous infusion of nicotine
Note: Dose: 4.0 mg/kg/hr
View evidence from paper
“DBA mice were chronically treated with nicotine by continuous intravenous infusion of 4.0 mg/kg/hr for 10 d”
Assessment of tolerance to acute nicotine effects
Evaluate tolerance development to acute effects of nicotine on locomotor activity and body temperature in drug-treated mice
Note: Conducted after chronic treatment period
View evidence from paper
“Drug-treated mice were tolerant to the acute effects of nicotine on locomotor activity and body temperature”
Brain tissue collection and sectioning
Brains were removed and sectioned for analysis
View evidence from paper
“Subsequently brains were sectioned and L-3H-nicotine binding was measured using quantitative autoradiographic methods”
Quantitative autoradiographic measurement
Measure L-3H-nicotine binding in brain sections using quantitative autoradiographic methods
Note: Conducted in three brain regions: cortex, midbrain, and cerebellum
View evidence from paper
“brains were sectioned and L-3H-nicotine binding was measured using quantitative autoradiographic methods”
In situ hybridization histochemistry
Determine relative amounts of mRNA for nicotinic receptor subunits (alpha 4, beta 2, alpha 2, alpha 3, and alpha 5)
Note: Followed by quantitation of image intensity
View evidence from paper
“the relative amounts of mRNA for the major nicotinic receptor subunits (alpha 4 and beta 2), as well as for three additional minor subunits (alpha 2, alpha 3, and alpha 5), were determined by in situ hybridization histochemistry followed by quantitation of image intensity”