Relation between the temporal pattern parameters of electrical stimulation of a neuron and gene expression

As known the long-term electrical activity of a neuron is accompanied by changing expression of early and late genes (Greenberg et al. 1985). Results of these changes are synthesis of ion channel proteins (Garcia, et al. 1994) and neurotransmitters (Hodaie et al. 1995) translating short-term environmental signals into relatively long-term changes in neuronal function. Transcription of early genes is activated within minutes of stimulation (Morgan and Curran 1986). Late gene expression is induced more slowly, within hours, and is controlled by regulators proteins that are products of the early genes (Goldman et al. 1988). Action of neurotransmitters, neurotrophic growth factors, and the membrane depolarization are thought to be stimuli inducing expression of early genes (Morgan and Curran 1991). One of the early genes widely used in experimental studies is c-fos gene that participates in responses to brain injury, sensory stimulation, activation of neurotransmitter receptor, stress, and long-term changes in efficiency of synaptic transmission (Hughes and Dragunow 1995). Transmission of information about changes of electrical stimulus from the neuronal membrane to genes is realized by several different intracellular signaling pathways in activation of which the second messenger Ca plays an essential role. Such structure of the signal transmission allows us to separate the problem of defining stimulustranscription coupling into two ones: . determination of relations between parameters of temporal pattern of electrical stimulus and parameters of temporal pattern of oscillations of intracellular calcium concentration ([Ca]), . identification of relations between parameters ofthe temporal pattern of [Ca] oscillations and expression intensity.