Lalo U. Changes in mechanisms of purinergic calcium signalling in rat sensorimotor neurons in postnatal ontogenesis

Dissertation is devoted to investigation of intracellular calcium signalling mechanisms in neurons of II-III layers of sensorimotor cortex in thin brain slices in situ. Neocortical neurones were loaded with calcium indicator Fura-2/AM. The principal mechanisms of calcium signals generation were examined for different age group neurons and for the first time demonstrate the existence of iono - and metabotropic mechanisms of exiting these neurons. Property of inositoltriphosphate - and caffeine-sensitive calcium stores were described. It was demonstrated that metabotropic Р2У purinoreceptors are present in all neurons of 14-days rats (P14), at the same time only 1/3 of the tested P30 neurones exhibited responses to applications of ATP in Ca2+- free solution. No caffeine - induced Ca2+-release has been observed in the P14 neurons. To the contrary, in neurones of the P30 group caffeine application induced considerable [Ca2+]i transients and respective calcium store becomes play an essential role in intrace llular calcium signalling.