Heroin in the Brain http://www.pbs.org/wgbh/pages/frontline/shows/heroin/brain/ natural opiates PBS neurological and psychological impact Scientists at Johns Hopkins University http://www.pbs.org/wgbh/pages/frontl.../heroin/brain/ PBS Endorphins released during sexual activity another explanation https://www.pbs.org/wgbh/pages/frontline/shows/heroin/brain/ http://www.pbs.org/wgbh/pages/frontline/shows/heroin/brain/ affect the workings of your brain we have what is called opiate receptors heroin http://www.pbs.org/wgbh/pages/frontline/shows/heroin/brain/ 8-12 hours http://www.pbs.org/wgbh/pages/frontline/shows/heroin/brain/ ‘natural opiates’