Cognitively demanding experiences, including complex skill acquisition and processing, have been
shown to induce brain adaptations, at least at the macroscopic level, e.g. on brain volume and/or
functional connectivity. However, the neurobiological bases of these adaptations, including at the
cellular level, are unclear and understudied. Here we use bilingualism as a case study to investigate
the metabolic correlates of experience-based brain adaptations. We employ Magnetic Resonance
Spectroscopy to measure metabolite concentrations in the basal ganglia, a region critical to language
control which is reshaped by bilingualism. Our results show increased myo-Inositol and decreased
N-acetyl aspartate concentrations in bilinguals compared to monolinguals. Both metabolites are
linked to synaptic pruning, a process underlying experience-based brain restructuring. Interestingly,
both concentrations correlate with relative amount of bilingual engagement. This suggests that
degree of long-term cognitive experiences matters at the level of metabolic concentrations, which
might accompany, if not drive, macroscopic brain adaptations.