Mancillas J R, Selverston A I
J Comp Neurol. 1985 Aug 1;238(1):38-52. doi: 10.1002/cne.902380104.
The distribution of substance P-like immunoreactivity (substance P-li) in the central nervous system of Limulus polyphemus was studied by using indirect immunocytochemical techniques. Six bilaterally symmetrical pairs of cell clusters in the circumesophageal connectives and the subesophageal mass contain substance P-li. Two of those pairs are the source of a system of efferent fibers that is involved in the expression of circadian rhythms of photosensitivity by the lateral eye. Substance P-li-containing cells were also observed scattered along the length of the circumesophageal connectives, which contain abundant stained fibers and some terminals. Substance P-li fibers leave through the ventral and dorsal nerves of the posterior circumesophageal ring. The neuropil of the subesophageal mass contains an abundance of stained terminals. Immunoreactive fibers can be seen throughout the length of the two longitudinal connectives of the ventral cord, in discrete fiber tracts in the lateral edges of the interganglionic connectives, and in the dorsal and ventral nerves of abdominal ganglia 1-4. Each of these ganglia contains three pairs of substance P-immunoreactive cell body clusters: an anterolateral, a medial longitudinal, and a medial posterior cluster. Substance P-li fibers entering through the ventral (posterior) nerves form very distinctive fascicles in each side of the ganglia, giving off fibers throughout their length. The neuropil is filled with immunoreactive terminals distributed homogeneously. The anterolateral clusters of the abdominal ganglia may be involved in cardioregulation. The six pairs of clusters in the posterior circumesophageal ring, and perhaps some of those in the abdominal ganglia, are believed to constitute a neurosecretory system, projecting to multiple targets throughout the organism. This system is postulated to modulate various sensory inputs and motor activity, and could be driven by a circadian clock, as well as by other systems responsible for integrated organismic responses.
利用间接免疫细胞化学技术研究了美洲鲎中枢神经系统中P物质样免疫反应性（P物质-li）的分布。在食管周围结缔组织和食管下神经节中有六对双侧对称的细胞簇含有P物质-li。其中两对是传出纤维系统的来源，该系统参与侧眼光敏性昼夜节律的表达。还观察到含P物质-li的细胞沿食管周围结缔组织全长散在分布，该结缔组织含有丰富的染色纤维和一些终末。P物质-li纤维通过食管后环的腹侧和背侧神经离开。食管下神经节的神经毡含有大量染色终末。免疫反应性纤维可见于腹神经索两条纵行结缔组织的全长、神经节间结缔组织外侧边缘的离散纤维束以及第1-4腹神经节的背侧和腹侧神经中。每个神经节含有三对P物质免疫反应性细胞体簇：一个前外侧簇、一个内侧纵行簇和一个内侧后簇。通过腹侧（后）神经进入的P物质-li纤维在神经节的每一侧形成非常独特的束，在其全长发出纤维。神经毡充满了均匀分布的免疫反应性终末。腹神经节的前外侧簇可能参与心脏调节。食管后环中的六对簇，可能还有腹神经节中的一些簇，被认为构成一个神经分泌系统，投射到整个生物体的多个靶点。推测该系统调节各种感觉输入和运动活动，并可能由昼夜节律钟以及负责综合机体反应的其他系统驱动。
