F = @(x)x(1)-x(end);
result = cellfun(F,C);
where C is your cell array. Note that since the diffrerence between first and last element of each array is a scalar, you don't need to store the result in a cell array; a regular numeric array will do, and that's what the above code does. However, if you really want the result to be a cell array, just tell cellfun 'UniformOutput',false.
result = cellfun(F,C,'UniformOutput',false);
Adjust the anonymous function as required, e.g., you might actually want @(x)x(end)-x(1) or @(x)abs(x(1)-x(end)).
