Introduction: GDH and related topics

The formulation of the Gerasimov-Drell-Hearn sum rule is revisited, showing its connection with other sum rules occurring in electron scattering and discussing the problem of its saturation, both from the theoretical and experimental point of v iew. The generalisation to other nuclear targets is also reported.Comment: 9 pages, talk given at GDH2002 conferenc

Systematic study of longitudinal and transverse helicity amplitudes in the hypercentral Constituent Quark Model

The predictions of the hypercentral Consituent Quark Model for the nucleon helicity amplitudes are briefly reported. Some future perspectives are also discussed