How to emtpy part of a matrix?

If I have a matrix like this :

    a = [1 2; 3 4; 5 6; 7 8]

is there a quick way to remove '3' and '4' from the matrix so it looks like :

   a  = [1 2; [] 4; [] 6; 7 8]?

I only want to remove value in the 1st column starting on the 2nd row and ending at the 2nd last row.

THANKS!

Answer 1

[Andrei Bobrov]

a = [1 2; 3 4; 5 6; 7 8];
a(2:3,1) = nan;

[Terek Li]

perfect, thanks!