will argument passing cause memory leak in Node.js

I've known that using closure like this will cause memory leaks because all other variables does not released.

function()
{
  var a = 0;
  var b = 1;
  sample_func( "123",function(){
    console.log(b+1);
  });
}

But how does this?

function()
{
   var a = 0;
   var b = 1;
   rtn_func(b);
}

var rtn_func = function(b){
    console.log(b+1);
}

Will passing variable to other functions as argument cause memory leak in Node.js?

Updated: after trn_func, will b auto-released?