报告人：AlbertGoldbeter
（Facultyof Sciences, Université Libre de Bruxelles (ULB), Brussels, Belgium）
时间地点： 9月11日下午4点， 维格堂109
Abstract
Pulsatile signaling represents a major mode of intercellularcommunication. It allows for the encoding of information through modulatingboth the amplitude and the frequency of pulsatile signals. Examples ofpulsatile intercellular communication include pulsatile hormone secretion andperiodic signals of cyclic AMP (cAMP) in Dictyostelium amoebae.Oscillations in intracellular Calcium provide an additional example offrequency encoding of pulsatile signals within cells. Mathematical models basedon experimental observations allow us to uncover the molecular mechanism offrequency encoding of pulsatile signals in intercellular communication. Twoexamples of frequency encoding will be considered: cAMP pulses in Dictyostelium cellsand pulsatile patterns of hormone secretion. In both cases mathematicalmodeling indicates how frequency encoding is based on reversible receptordesensitization. The modeling approach shows that pulsatile cAMP signalingin Dictyostelium is closely related with pulsatile hormonesecretion in higher organisms. In both cases there exists an optimal frequencyof pulsatile intercellular communication. These results bear on humanphysiology as it is now clear that most hormones (growth hormone, insulin,gonadotropin-releasing hormone,…) are secreted in a pulsatile manner. Theresults support the view that the temporal pattern of a hormone is often asimportant as its concentration in the blood.