Dear Dr. Scouten, I find your contributions to the List very informative and truly valuable in keeping us on the right track when it comes to explanations and answers to some of the "scientific" questions that come up. I was hoping that you might address a question of mine which relates to your recent post concerning mitochondria. You point out that mitochondria is transmitted from the mother only. In my reading concerning possible causes of PD, I have come across articles that mention mitochondria as a possible factor in PD. Does the fact that an individual's mitochondria comes only from the mother's side tend to rule it out as a causitive factor in PD? Thank you for your contributions to the List. Dee ---------------------------------------------------------------------- To sign-off Parkinsn send a message to: mailto:[log in to unmask] In the body of the message put: signoff parkinsn