Beta-lactam antibiotic decreases acquisition of and motivation to respond for cocaine, but not sweet food, in C57Bl/6 mice.

No medication is approved to treat cocaine addiction, but mounting evidence suggests glutamate-directed approaches may reduce cocaine dependence and relapse. We tested the hypotheses that the glutamate transporter subtype 1 (GLT-1) activator ceftriaxone disrupts acquisition of cocaine self-administration, motivation to self-administer cocaine, and conditioned place preference in mice. Repeated ceftriaxone (200 mg/kg) reduced the ability of mice to acquire cocaine and the motivation to self-administer cocaine following successful acquisition without affecting acquisition of or motivation for sweet food. Repeated ceftriaxone had no effect on cocaine-conditioned place preference. These results suggest that a β-lactam antibiotic reduces the direct reinforcing strength of cocaine without producing non-specific deficits in conditioned learning processes.