There is a way.
set(groot, 'DefaultAxesYLim', [-0.3955,-0.3935])
Better would probably be to use the handle of your figure instead of groot.
Personally I avoid setting default properties such as these, as it mentally removes the setting of the properties too far away from the code doing the plotting, making it difficult to debug. Typically it would be better to create a function that you explicitly call that sets the properties to make it obvious.
