Reassessment of the role of the central cholinergic system.

The central cholinergic system is believed to be involved in the control of many physiological functions and is an important pharmacological target for numerous neurological pathologies. Here, we summarize our recent observations regarding this topic that we obtained by studying genetically modified mice devoid of particular cholinesterase molecular forms. Our results, collected from mice with deficits of functional cholinesterases in the brain, suggest that the increase in the level of acetylcholine (ACh) has an impact on cognition only in the situation when extracellular ACh is low. Furthermore, we confirmed the central control of movement coordination, which could be of importance for the management of motor problems in patients with Parkinson's disease. At last, we provide clear evidence that while the hypothermic effect of the muscarinic agonist oxotremorine is based on a central mechanism, in contrast, the acetylcholinesterase inhibitor donepezil decreases body temperature by its action in the periphery.