Increase in excitability of hippocampal neurons during novelty-induced hyperlocomotion in dopamine-deficient mice.

Dopamine is involved in many important brain functions, including voluntary motor movement. Dysfunction of the dopaminergic system can induce motor impairments, including Parkinson's disease. We previously found that dopamine-deficient (DD) mice became hyperactive in a novel environment 72 h after the last injection of L-3,4-dihydroxyphenylalanine (L-DOPA) when dopamine was almost completely depleted.