Abstract : This thesis deals with two types of problems : first the cooling and the dynamics of atoms in grey molasses and grey lattices, second the presentation of a new spectroscopic method to study the atomic dynamics in bright lattices. In potential structures such as grey molasses, Cesium atoms are cooled to very low temperatures (800 nK) since they are trapped in states where they experience a very weak influence of light. The addition of a strong static magnetic field then transforms the potential structure seen by the atoms in a landscape of hills regularly separated by flat valleys. In this new environment called grey lattice, the dynamical behaviour of atoms becomes unusual: they bounce like a pinball on the potential antidots. Bright lattices in comparison, exhibit a potential structure loooking like of a landscape of pits (potential wells) in which atoms remain trapped. In order to study in more details the atomic dynamics in such bright lattices, we implemented the spectroscopic technic of "coherent transient". The very good signal to noise ratio given by this technic and an increased frequency selectivity allowed us to attribute to the potential anharmonicity the main part of the relaxation of the atomic oscillation in the potential wells. Besides, this technic allowed a quantitative study of the atomic transport in bright lattices.