Referencing an Selector items panel

I have this,

static MySelector()

{

DefaultStyleKeyProperty.OverrideMetadata(typeof(MySelector), new FrameworkPropertyMetadata(typeof(MySelector)));

}

with a Generic Template as,

<Style TargetType="{x:Type local:MySelector}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type local:MySelector}">
                    <local:MyGrid x:Name="MyGrid" IsItemsHost="True"/>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

and I am trying to get a reference to 'MyGrid' via code within MySelector (OnInitialized) but I can't. I know there's a simple solution here but I can't seem to find it.