class MouseOverComponent extends React.Component {

  componentDidMount() {
    this.mouseMove$ = Rx.Observable.fromEvent(this.mouseDiv, "mousemove")
      .throttleTime(1000)
      .subscribe(() => console.log("throttled mouse move"));
  }

  componentWillUnmount() {
     this.mouseMove$.unsubscribe();
  }

  render() {
    return (
      <div ref={(ref) => this.mouseDiv = ref}>
          Move the mouse and look at the console...
      </div>
    );
  }
}