In this talk I will present the measurement of the extended GDH integral evolution from intermediate to low on the He and neutron.
One of the main goals of Jefferson Lab is to understand the transition between the nuclear domain (low , nucleon and meson degrees of freedom) and the perturbative QCD domain (large , quark and gluon degrees of freedom) of the strong interaction. It has been pointed out that the extended GDH sum-rule  was a unique tool to study this transition domain.
This experiment  was carried out in the Hall A of the Thomas Jefferson National Accelerator Facility. In order to achieve such a study on the neutron we used a high-density polarized He target. We measured the spin dependent inclusive cross sections. From them we extract the two spin structure functions , and the GDH integrand . The GDH sum rule stands also for He and provides valuable information on its nuclear structure. After a brief description of the experimental setup and having discussed the extraction of the neutron information from the He data, we will present our results and give an outlook on future perspectives.
 Z.-E. Meziani, G. Cates, J.-P. Chen et al., Jefferson lab experiment E94010. www.jlab.org/e94010
 D. Drechsel, S.S. Kamalov G. Krein and L. Tiator. The Generalized Gerasimov -Drell-Hearn Integral and the Spin Structure of the Nucleon. Phys.Rev. 59 094021. (1999);
 X. Ji and J. Osborn. Generalized Sum Rules for Spin Dependent Functions of the Nucleon. J.Phys. G27 127 (2001).