JavascriptMVC: Listen to event of instantiated Controller in wrapper Controller

I have 2 controllers:

$.Controller('App.Browse',
/** @Static */
{
    defaults : {}
},
/** @Prototype */
{
    init : function(){
        $('#map').app_map();
    },
    // how can I listen here for an event of app_map() controller
})

and

$.Controller('App.Map',
/** @Static */
{
    defaults : {}
},
/** @Prototype */
{
    init : function(){
        // how can I trigger an event to be listened by app_browser() controller
    },
})

The short idea is that while I'm in the App.Map controller I would like to notice the App.Browse controller to do something.

JMVC is prepared for that. Just declare it like this:

$.Controller('App.Browse',
/** @Static */
{
    defaults : {
        mapController: null
    },
    listensTo: ['mapCustomEvent']
},
/** @Prototype */
{
    init : function(){
        $('#map').app_map();
    },

    '{mapController} mapCustomEvent': function(element, event, param) {
        //handle event
    }
})

$.Controller('App.Map',
/** @Static */
{
    defaults : {}
},
/** @Prototype */
{
    init : function(){
        param = "something I'd like to pass into event listener";
        $(this).trigger('mapCustomEvent', params);
    }
})

And instantiate:

map = new App.Map('#map');
new App.Browse($('#browse'), {mapController: map});