Attention acetylcholine

After an overview of neurotransmitter systems and function and a consideration of which substances can be classified as neurotransmitters, section A deals with their release, effects on neuronal excitability and receptor interaction. The synaptic physiology and pharmacology and possible brain function of each neurotransmitter is then covered in some detail (section B). Special attention is given to acetylcholine, glutamate, GABA, noradrenaline, dopamine, 5-hydroxytryptamine and the peptides but the purines, histamine, steroids and nitric oxide are not forgotten and there is a brief overview of appropriate basic pharmacology. 

Whitehouse, P. J. (2004). Paying attention to acetylcholine the key to wisdom and quality of life Prog. Brain Res. 145, 311-17. 

Traditionally, most affective disorders have been treated with compounds that resemble the neurotransmitters that are deficient or in excess in specific brain regions. The aberrant levels of neurotransmitters (or their receptors), such as norepinephrine, dopamine, acetylcholine, and serotonin, have correlated with behavioral symptoms of schizophrenia, depression, anxiety, sleep disorders, motor dysfunctions, attention difficulties, and cognitive disorders. Most drugs discovered for these disorders resulted from screening compounds directly in rodent behavioral models that mimic the behavior of the disease. In these cases, the molecular target" or mechanism of action was assumed to be the deficiency or excess of a neurotransmitter. 

Himmelheber AM, Sarter M, Bruno JP. 2000. Increases in cortical acetylcholine release during sustained attention performance in rats. Brain Res Cogn Brain Res 9(3) 313-325. 

With reference to divided attention, an association has been reported between blood glucose levels and performance on effortful dichotic listening paradigm (Parker Benton, 1995). While similar effects have been attributed to acetylcholine precursor (acetyl CoA) synthesis linked to glucose metabolism (Wenk, 1989), it is also possible that simple provision of metabolic substrates may account for such findings (Kennedy Scholey, 2000). 

Experiments in my laboratory and in others have demonstrated that the appearance of this wave of electrical activity requires the normal function of acetylcholine within your frontal cortex. If the acetylcholine neurons that project into your frontal cortex are destroyed, then this wave cannot fully form and you will have great difficulty paying attention to important things, such as the impending appearance of a masked gunman. An example of such a wave is labeled post in the figure. In this case, the absence of acetylcholine does not allow the wave to fully develop. This research has demonstrated that acetylcholine s job is to instruct the neurons in your frontal cortex to pay attention to important information and be vigilant to... 

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