PMC

Alcohol and saccharin choice (Exp. 1). a Timeline of the experiment. b Self-administration and choice of alcohol and saccharin (0.05%): Mean ± SEM number of alcohol and saccharin (0.05%) deliveries during the last 8 days of self-administration (left) and the 5 daily choice tests (right). c Self-administration and choice of alcohol and saccharin (0.1%): Mean ± SEM number of alcohol and saccharin (0.1%) deliveries during self-administration (left) and subsequent choice tests (right). d Effect of deprivation of alcohol and saccharin on choice between alcohol and saccharin: Mean ± SEM number of alcohol and saccharin deliveries during choice tests before and after 10 days of alcohol and saccharin deprivation. e Effect of ITI duration on choice between alcohol and saccharin: Mean ± SEM number of alcohol and saccharin deliveries during choice tests with 2 and 5 min ITIs. *Different from alcohol, ⁺different from pre-deprivation baseline (d) or from 2 min ITI (e) (ps < 0.05). N = 31. ASA alcohol self-administration, SSA saccharin self-administration, ITI intertrial interval

Effects of alcohol dependence on choice of alcohol over saccharin (Exp. 2). a Timeline of the experiment. b Self-administration and choice of alcohol and saccharin (0.1%) prior to dependence induction: Mean ± SEM number of alcohol and saccharin (0.1%) deliveries during the last 8 days of alcohol and saccharin self-administration (FR-3) (left) and during the 5 daily choice tests (right). c Effects of alcohol dependence on self-administration of alcohol and saccharin: Mean ± SEM number of alcohol (left) and saccharin (right) deliveries during self-administration sessions conducted after the first 3 cycles of alcohol vapor exposure. d Effects of alcohol dependence on choice between alcohol and saccharin: Mean ± SEM number of alcohol (left) and saccharin (right) deliveries during the choice tests conducted after the first 4 cycles of alcohol vapor exposure. e Effects of concurrent access to alcohol and saccharin on self-administration in non-dependent and alcohol dependent rats: Mean ± SEM number of alcohol (left) and saccharin (right) deliveries during sessions with access to alcohol or saccharin alone or with concurrent access to both reinforcers. f Effects of alcohol dependence on decreases in alcohol self-administration produced by adulteration of alcohol with quinine: Mean ± SEM number of alcohol deliveries during self-administration tests with unadulterated alcohol (0 concentration) or alcohol adulterated with 0.05 and 0.1 g/L quinine in control (left) and alcohol dependent (right) rats. g Effects of alcohol dependence and quinine adulteration of alcohol on choice between alcohol and saccharin: Mean ± SEM number of alcohol (left) and saccharin (right) deliveries during choice tests with unadulterated alcohol (0 concentration) or alcohol adulterated with 0.05 and 0.1 g/L quinine in control and alcohol dependent rats. *Different from alcohol, ⁺different from non-dependent controls, ^#different from saccharin alone (e) or from 0 quinine concentration condition (f) (ps < 0.05). N = 15–16/group. ASA alcohol self-administration, SSA saccharin self-administration

i.v. nicotine and saccharin choice (Exp. 3). a Timeline of the experiment. b Nicotine and saccharin self-administration and choice: Mean ± SEM number of nicotine and saccharin deliveries during the 8 days of i.v. nicotine and saccharin self-administration (left) and subsequent 4 daily choice tests (right). c Effect of ITI duration on choice between i.v. nicotine and saccharin: Mean ± SEM number of nicotine and saccharin deliveries during choice tests with 2 and 5 min ITIs. d Effects of concurrent access on self-administration of i.v. nicotine and saccharin: Mean ± SEM number of nicotine and saccharin deliveries during sessions with access to nicotine or saccharin alone or with concurrent access to both. *Different from nicotine (ps < 0.05). N = 10. NSA nicotine self-administration, SSA saccharin self-administration, ITI intertrial interval, FR fixed ratio

A–C Responding for saccharin is not reduced following saccharin devaluation by specific satiety. A Rats’ performance on the cocaine and saccharin levers did not differ between the devalued group (D; white) and the non-devalued group (ND; blue) across 1 min time bins in the extinction test. *p < 0.05 Coc vs. Sacch. B The total number of lever presses was higher on the saccharin lever compared to the cocaine lever but was not affected by devaluation. *p < 0.05 Coc vs. Sacch. C Saccharin was correctly devalued as measured by a reduction in posttest consumption of saccharin in the D group compared to the ND group. D–F Preference for saccharin is also insensitive to saccharin devaluation by CTA. D, E Rats responded more on the saccharin lever compared to the cocaine lever but did not differ as a function of devaluation. *p < 0.05 Coc vs. Sacch. F Devaluation of saccharin was confirmed during the test of consumption immediately after the extinction session. Adapted from [].