But these blood vessels are different from all the other blood vessels in our body. They are lined by a strange structure called the blood-brain barrier. It closely controls what is, and is not, allowed to leave the blood supply and enter the brain.It's your own personal customs and border security.We used to think of the blood-brain barrier as some kind of biological flyscreen.hey are lined by a strange structure called the blood-brain barrier. It closely controls what is, and is not, allowed to leave the blood supply and enter the brain. It's your own personal customs and border security. We used to think of the blood-brain barrier as some kind of biological flyscreen.
Follow this guide to find the best time to see Smoky Mountain fall colors. September. Fall in the Smokies begins in September, with the emerging changes occurring above 4,000 feet. Red, orange and yellow colors can be seen on sourwood, dogwood, maple, sassafras and birch trees. Drives recommended for September viewing are Parsons Branch Road, Newfound Gap Road and Clingmans Dome Road.
Seeing the changing autumn leaves is a longstanding Colorado tradition that generally takes place mid-September to mid-October each year, and AAA Colorado, the Colorado Department of Transportation (CDOT), and Colorado Parks and Wildlife want to let people know where to drive and how to drive safely for some of the best views this season.