What resolves this contention: Co-release of classical transmitters (GABA, glut…

What resolves this contention: Co-release of classical transmitters (GABA, glutamate) from modulatory neurons is a widespread, functionally important signaling mode with distinct postsynaptic effects / Some co-release observations may be artifacts of optogenetic stimulation at non-physiological frequencies, and the functional relevance of co-release under natural conditions remains contested