How to delete extra space between row in WPF datagrid

Good morning,

I am working on a WPF application. I have a datagrid which is bound with a collection of object.
I have a graphical problem cause there is like an additional space between each row of the datagrid.
I used CanUserAddRows="False" for the datagrid but i have still the space.

Does someone have an idea to fix this problem ?

Thank you in advance.