Figure 2: GLP-1 regulates nicotine intake.
From: GLP-1 acts on habenular avoidance circuits to control nicotine intake
(a) Mechanisms of GLP-1 receptor (GLP-1R) activation by sitagliptin and Ex-4. (b) Intravenous nicotine self-administration procedure. (c) Mean (± s.e.m.) number of nicotine infusions earned by mice after Ex-4 (10 μg/kg) administration. ***P < 0.0001, paired t-test (n = 10). (d) Mean (± s.e.m.) number of nicotine infusions earned by mice after sitagliptin administration. **P = 0.0093, paired t-test (n = 12). (e) Nicotine dose–response curve in GLP-1R knockout (n = 8) and wild-type (n = 6) mice. Data points represent mean (± s.e.m.) number of infusions earned at each nicotine dose. Two-way repeated-measures (RM) ANOVA, genotype: F(1,12) = 6.29, *P = 0.0275; nicotine: F(2,24) = 9.49, P = 0.0009; genotype × nicotine: F(2,24) = 0.18, P = 0.8364. (f) Mean (± s.e.m.) number of food rewards earned during 1-h operant training sessions between GLP-1R knockout (KO; n = 9) and wild-type (n = 12) mice.
