Release of neurotransmitters in the monkey frontal cortex is related to level of attention

Abstract

Attention is reported to be maintained by monoamines, acetylcholine and amino acids systems. Changes in the releases of these neurotransmitters during the three stages comprising quiet wake (QW) and two arousal states (AW), which are activated from different sources, were investigated. Norepinephrine releases during AW were significantly higher than that during QW. Conversely, the levels of acetylcholine and serotonin that were released did not change significantly among these three stages. The interesting observation was the dissociation of the increase between glutamate and dopamine releases in the two AW states. These results indicate that attention level is related to the amount of norepinephrine release, and that attention quality is related to the interaction between dopamine and glutamate releases.