The Existence of a Linear System Consisting of Sympathetic Endings in Rat Skin
August 2005
in “
Anatomy and Embryology
”
TLDR Rat skin has a linear system of nerve fibers linked to hair follicles and muscles.
The study investigated the distribution of catecholaminergic sympathetic nerve endings in rat skin, revealing a non-homogeneous pattern. Using macro-autoradiography with iodine-125-labeled tyrosine and light microscopy autoradiography with tritiated tyrosine, researchers identified symmetrical linear arrays of catecholamine distribution, termed sympathetic substance lines (SSLs), running from the head to the hind limbs. These lines were associated with hair follicles and arrector pili muscles (AP muscles). The study concluded that dense clusters of noradrenergic nerve fibers innervate AP muscles, forming a longitudinal linear system in the skin, which may relate to physiological functions of hair follicles, sensory pathways, and traditional Chinese medicine meridians.
