September 26, 2024 by Mario Aguilera, University of California – San Diego In normal mice (left), magenta neurons express the excitatory transmitter glutamate and green neurons express the inhibitory transmitter GABA. Methamphetamine (right) causes glutamate-expressing neurons to express GABA, demonstrated by neurons co-expressing magenta and green labels (arrowheads) in methamphetamine-treated mice but not in untreated...