Interstate 635 (Texas) Interstate 635 (Texas) Interstate 635 (I-635) is a partial loop around Dallas, Texas, in the United States between I-20 in Balch Springs and State Highway 121 (SH 121) at the north entrance of the Dallas-Fort Worth International Airport in Grapevine. It intersects I-35E at exits 27B–C, but does not connect with I-35W. It is known locally as the Lyndon B. Johnson Freeway, or LBJ, named after Lyndon B. Johnson, the former U.S. Senator from Texas, 37th Vice President, and the 36th President of the United States. Where I-635 ends at I-20, I-20 continues the LBJ Freeway name heading west. Because
Referred pain in the dorsal horn. This signal could then be perceived as referred pain. Several characteristics are in line with this mechanism of referred pain, such as dependency on stimulus and the time delay in the appearance of referred pain as compared to local pain. However, the appearance of new receptive fields, which is interpreted to be referred pain, conflicts with the majority of experimental evidence from studies including studies of healthy individuals. Furthermore, referred pain generally appears within seconds in humans as opposed to minutes in animal models. Some scientists attribute this to a mechanism or influence downstream in the