Persson M G, Nässel D R
Department of Zoology, Stockholm University, S-10691, Stockholm, Sweden.
Brain Res. 1999 Jan 16;816(1):131-41. doi: 10.1016/s0006-8993(98)01139-1.
Sensory afferents in the thoracic ganglia of the locust Locusta migratoria were labelled with antisera to different neuropeptides: locustatachykinins, FMRFamide and allatotropin. The locustatachykinin-immunoreactive (LTKIR) sensory fibres were derived from the legs and entered the ventral sensory neuropil of each of the thoracic ganglia via nerve 5. In the thoracic neuropil, the LTKIR sensory fibres formed a distinct plexus of terminations ventrally in the ipsilateral hemisphere. The peripheral cell bodies of the sensory neurones could not be revealed, but lesion experiments indicated that origin of the LTKIR fibres was the tarsus of each leg. Possibly the thin fibres are from tarsal chemoreceptors. Double labelling immunocytochemistry revealed that all the LTKIR sensory fibres contained colocalized FMRFamide immunoreactivity. A larger population of sensory fibres reacted with antiserum to moth (Manduca sexta) allatotropin. By means of double labelling immunocytochemistry, we could show that the LTKIR fibres constituted a subpopulation of the larger set of allatotropin-like immunoreactive fibres. Thus some sensory fibres may contain colocalized peptides related to locustatachykinins, FMRFamide-related peptide(s) and allatotropin-like peptide. A separate non-overlapping small set of sensory fibres in nerve 5 reacted with an antiserum to serotonin. Sensory fibres of the other nerves of the ventral nerve cord, including the abdominal ganglia, did not react with the peptide antisera. Since acetylcholine is the likely primary neurotransmitter of insect sensory fibres, it is possible that the peptides and serotonin are colocalized with this transmitter and serve modulatory functions in a subset of the leg afferents.
用针对不同神经肽的抗血清标记了飞蝗（Locusta migratoria）胸神经节中的感觉传入纤维：速激肽、FMRF酰胺和促咽侧体素。速激肽免疫反应性（LTKIR）感觉纤维来自腿部，通过第5神经进入每个胸神经节的腹侧感觉神经纤维网。在胸神经纤维网中，LTKIR感觉纤维在同侧半球腹侧形成一个明显的终末丛。感觉神经元的外周细胞体无法显示，但损伤实验表明LTKIR纤维的起源是每条腿的跗节。可能细纤维来自跗节化学感受器。双重标记免疫细胞化学显示，所有LTKIR感觉纤维都含有共定位的FMRF酰胺免疫反应性。大量感觉纤维与针对蛾（烟草天蛾，Manduca sexta）促咽侧体素的抗血清发生反应。通过双重标记免疫细胞化学，我们可以表明LTKIR纤维构成了较大的一组类促咽侧体素免疫反应性纤维的一个亚群。因此，一些感觉纤维可能含有与速激肽、FMRF酰胺相关肽和类促咽侧体素肽共定位的肽。第5神经中一小部分单独的、不重叠的感觉纤维与5-羟色胺抗血清发生反应。腹神经索其他神经（包括腹神经节）的感觉纤维不与肽抗血清发生反应。由于乙酰胆碱可能是昆虫感觉纤维的主要神经递质，肽和5-羟色胺有可能与这种递质共定位，并在腿部传入纤维的一个亚群中发挥调节作用。
