Taste Reactivity in Alcohol Preferring and Nonpreferring Rats

Abstract

Taste reactivity tests were used to examine the orofacial responses of alcohol preferring (P) rats and alcohol nonpreferring (NP) rats to the taste of alcohol. In the initial exposure, naive rats were tested for reactivity to five concentrations of alcohol (5%, 10%, 20%, 30%, and 40% v/v), water, and one solution each of sucrose and quinine. A two‐bottle consumption test was then given for a 3‐week period to allow the rats access to 10% alcohol. After the preference test, a second taste reactivity test was done using the same solutions as in the initial reactivity test. The results indicated no significant differences in taste reactivity between P rats and NP rats on the initial exposure, except that NP rats made significantly more mouth movements. During the two‐bottle tests, consumption of alcohol by P rats was consistently higher than that of NP rats across all test days. On the second taste reactivity test, P rats showed an increase in the number of ingestive responses and a decrease in the number of aversive responses to alcohol. NP rats' taste reactivity to alcohol remained unchanged from Exposure 1 to Exposure 2. P rats' and NP rats' responses to sucrose and quinine did not change from Exposure 1 to Exposure 2. It was concluded that there were no innate taste response differences between P and NP rats to alcohol but that following alcohol experience, P rats showed a significant increase in ingestive responses and a concomitant decrease in aversive responses to the taste of alcohol. These data suggest that the taste of alcohol becomes more palatable to P rats after alcohol experience, a factor that may be important in the maintenance of continued high alcohol consumption by P rats.

Benzodiazepines enhance the consumption and palatability of alcohol in the rat

“…This is remarkable considering that even alcohol preferring (P) rats, which are genetically predisposed to consume very high levels of alcohol (Li et al 1979), show few hedonic responses to ethanol when alcohol-naive (Bice and Kiefer 1990;Kiefer 1995). Our observation that midazolam increases the hedonic response to ethanol also in alcohol-naive subjects may help to explain why druginduced increases in GABAergic transmission facilitate the acquisition of ethanol intake in rats (Smith et al 1992).…”

“…To control for the motor-impairing actions of the quite high doses of midazolam employed here, we also studied the e¤ect of the neuroleptic, cis(Z)ßu-pentixol, at a high cataleptic dose. Earlier studies relating ethanol preference to gustatory mechanisms include observations that rat lines high in alcohol consumption show unusually high levels of hedonic responses to the taste of alcohol (Bice and Kiefer 1990;Kiefer 1995), although Fahlke et al (1994) observed no correlation between home cage ethanol consumption and alcohol taste reactivity in our strain of unselected Wistar rats. Kiefer and Dopp (1989) reported that rats with access to alcohol in the home cage show fewer aversive responses to ethanol in the taste reactivity test compared to alcohol-naive subjects.…”

Alcohol Preference Influences the Subthalamic Nucleus Control on Motivation for Alcohol in Rats

“…Instead of an effect on motivation for alcohol, STN lesions may have influenced the aversion mechanisms, as it has been shown that alcohol aversion is lower in alcohol preferring rats (tolerance to aversion) (Bice and Kiefer, 1990). As there was no difference between sham and STN rats on alcohol consumption, it is unlikely that STN lesions have induced a shift in alcohol-induced aversion tolerance.…”

Effects of Nicotine on Olfactogustatory Incentives: Preference, Palatability, and Operant Choice Tests

“…To equate for total volume and to account for dead space in the tubing, the syringe pump was set to an infusion rate of 1 ml/min and the pump remained activated for 1 min after an initial facial reaction (mouth movement) was observed by the experimenter (Bice & Kiefer, 1990). At the end of 1 min, the syringe pump was turned off, and facial reactions were recorded for one additional minute.…”