Intracellular mechanisms of glutaminergic and cholinergic signal transduction in the cerebral cortex.

A complex method was used to study the effects of acetylcholine and glutamine on the dynamics of calcium and polyphosphoinositide regulatory system activities over prolonged periods of time in the mammalian cerebral cortex, after exposure to these substances in baseline conditions and in conditions of developing adaptive responses. Adaptive responses were induced by transient hypoxia with oxymetacil as an antioxidant. Agonist stimulation of choline and glutamate receptors produced prolonged calcium and phosphoinositide responses in cortical structures; these had specific characteristics after exposure to glutamate and acetylcholine. During the development of adaptive responses, these changes underwent significant modifications. The functional importance of these effects is discussed.