The stomatogastric nervous system of the medicinal leech: its anatomy, physiology and associated aminergic neurons.

Autor: Mesce KA; Departments of Entomology and Neuroscience, University of Minnesota, St Paul, MN 55108, USA mesce001@umn.edu., Alania M; Department of Biology, Faculty of Exact and Natural Sciences, Ivane Javakhishvili Tbilisi State University, Tbilisi, Georgia., Gaudry Q; Department of Biology, University of Maryland, College Park, MD 20742, USA., Puhl JG; Departments of Entomology and Neuroscience, University of Minnesota, St Paul, MN 55108, USA.
Jazyk: angličtina
Zdroj: The Journal of experimental biology [J Exp Biol] 2018 Mar 29; Vol. 221 (Pt 7). Date of Electronic Publication: 2018 Mar 29.
DOI: 10.1242/jeb.175687
Abstrakt: Blood feeding is an essential and signature activity of the medicinal leech species H irudo verbana . Despite keen interest in understanding the neuronal substrates of this behavior, a major component of the nervous system associated with feeding has remained overlooked. In this study, for the first time, we report on the presence and characteristics of five stomatogastric ganglia (STGs) comprising the visceral stomatogastric nervous system (STN) of the leech. Although a brief report was published by Ruth Hanke in 1948 indicating that a ring of three ganglia (not five) was associated with the cephalic ganglia, this information was never integrated into subsequent neurobiological studies of feeding. Here, the anatomical features of the STGs are described, as are the morphological and electrophysiological characteristics of neurons originating in them. We also determined that two of the five STGs (STG-1 and STG-3) each contained two relatively large (ca. 40 µm diameter) serotonergic neurons. The STN was also enriched with dopaminergic and serotonergic arborizations; however, no intrinsic dopaminergic somata were observed. The trajectory of the serotonergic large lateral (LL) neuron, a command-like cell for feeding, was documented to project directly to the STN and not to the jaw and pharyngeal musculature as previously reported, thus reopening the important question of how the LL cell activates and coordinates biting activity with pharyngeal swallowing. Additional studies revealed that the LL cell is excited by blood serum applied to the lip and is strongly inhibited by dopamine. These findings provide a new foundation for understanding the regulation and modulation of neural networks involved in feeding.
Competing Interests: Competing interestsThe authors declare no competing or financial interests.
(© 2018. Published by The Company of Biologists Ltd.)
Databáze: MEDLINE