Brain-stem cholinergic system

The normally harmonious music of the aminergic neuronal spheres is contrapuntal to the brain stem cholinergic system, whose modulatory output is generally reciprocal to the aminergic groups and distinctly phasic and burstlike in character (rather than tonic and regular). In fact, the phasic bursts of acetylcholine (ACh) neuronal discharge appear to be strictly and precisely related to eye movement control by the paramedian reticular formation and the oculomotor system. 

Steriade, M., Datta, S., Pare, D., Oakson, G. 8r Curro Dossi, R. C. (1990a). Neuronal activities in brain-stem cholinergic nuclei related to tonic activation processes in thalamocortical systems. J. Neurosci. 10, 2541-59. 

The brain stem cholinergic neurons are essential for the regulation of sleep-wake cycles via projections to the thalamus. The cholinergic interneurons in the striatum modulate striatal GABAergic neurons by opposing the effects of dopamine. Increased cholinergic tone in Parkinson s disease and decreased cholinergic tone in patients treated with neuroleptics are examples of an imbalance of these two systems in the striatum (Cala-bresi et al., 2000). 

Afferent systems of the inferior olive have been reviewed by Brodal and Kawamura (1980) for the cat and by Martin et al. (1980) for the opossum. For the rat the tabulated summary of its afferent connections in the paper of Brown et al. (1977) and the review by Flumerfelt and Hryccyshyn (1985) are useful. Afferent systems of the inferior olive can be subdivided into three groups (1) the GABAergic nucleo-olivary and vestibulo-olivary projections (2) the monoaminergic and cholinergic projections to the inferior olive (3) the specific projections from the spinal cord, certain brain stem nuclei and the cerebral cortex will not be considered in this chapter. Their neurotransmitters are not known. 

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