obsolete larval intersegmental nerve of A1-7 [FBbt_00007314]

obsolete larval intersegmental nerve of A1-7

ID: FBbt_00007314

Larval intersegmental nerve of larval segments A1-A7. It has two roots; an anterior root that is formed by neurons of the anteriorly adjacent neuromere, and a posterior root, that is formed by neurons of the same neuromere as the nerve (Campos-Ortega and Hartenstein, 1997). These roots converge and fuse shortly before leaving the ventral nerve cord (Campos-Ortega and Hartenstein, 1997). Proximally it shares a glial sheath with the segmental nerve before branching from it at the ventral edge of the ventral oblique muscles (Campos-Ortega and Hartenstein, 1997). It then runs dorsally, anterior to the segmental nerve (Campos-Ortega and Hartenstein, 1997). It has two ventral motor branches, ISNb and ISNd, which innervate the ventral lateral and ventral oblique muscles, respectively, and a lateral sensory branch that penetrates the lateral transverse muscle fibers to reach the lateral sensory cluster (Campos-Ortega and Hartenstein, 1997). Further dorsally, upon entering the dorsal muscle group, it splits to form an externally directed sensory branch connected to the dorsal sensory cluster, and an internally directed branch which carries efferent axons to the dorsal musculature (Campos-Ortega and Hartenstein, 1997).

Obsoleted as this is the same as 'larval abdominal intersegmental nerve' (no 'intersegmental' and 'segmental' nerves in A8-9).