Muscarinic autoreceptors related with calcium channels in the strong and weak inputs at polyinnervated developing rat neuromuscular junctions
Using intracellular recording, we studied how several muscarinic antagonists affected the evoked endplate potentials in singly and dually innervated endplates of the levator auris longus muscle from 3 to 6-day-old rats. In dually innervated fibers, a second endplate potential (EPP) may appear after...
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2004
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03064522_v123_n1_p61_Santafe http://hdl.handle.net/20.500.12110/paper_03064522_v123_n1_p61_Santafe |
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paper:paper_03064522_v123_n1_p61_Santafe2023-06-08T15:31:12Z Muscarinic autoreceptors related with calcium channels in the strong and weak inputs at polyinnervated developing rat neuromuscular junctions Uchitel, Osvaldo Daniel Cholinergic synapse Motor endplate Motor nerve terminal Polyneuronal innervation Voltage-dependent calcium channels acetylcholine calcium calcium channel calcium channel L type calcium channel N type calcium channel P type calcium channel Q type methoctramine muscarinic M1 receptor antagonist muscarinic M2 receptor antagonist muscarinic M4 receptor muscarinic receptor muscarinic receptor blocking agent otenzepad pirenzepine tropicamide acetylcholine release animal experiment animal tissue article controlled study drug effect endplate potential innervation intracellular recording neuromuscular synapse neurotransmitter release nonhuman priority journal rat Using intracellular recording, we studied how several muscarinic antagonists affected the evoked endplate potentials in singly and dually innervated endplates of the levator auris longus muscle from 3 to 6-day-old rats. In dually innervated fibers, a second endplate potential (EPP) may appear after the first one when we increase the stimulation intensity. The lowest and highest EPP amplitudes are designated "small-EPP" and "large-EPP," respectively. In singly innervated endplates and large-EPP, we found an inhibition of acetylcholine release by M1-receptor antagonists pirenzepine and MT-7 (more than 30%) and M2-receptor antagonists methoctramine and AF-DX 116 (more than 40%). The small-EPP was also inhibited by both M2-receptor antagonists methoctramine (approximately 70%) and AF-DX 116 (approximately 40%). However, the small-EPP was enhanced by M1-receptor antagonists pirenzepine (approximately 90%) and MT-7 (approximately 50%). The M4-receptor selective antagonists tropicamide and MT-3 can also increase the small-EPP amplitude (75% and 120%, respectively). We observed a graded change from a multichannel involvement (P/Q- N- and L-type voltage-dependent calcium channels) of all muscarinic responses (M1-, M2- and M4-mediated) in the small-EPP to the single channel (P/Q-type) involvement of the M1 and M2 responses in the singly innervated endplates. This indicates the existence of a progressive calcium channels shutoff in parallel with the specialization of the adult type P/Q channel. In conclusion, muscarinic autoreceptors can directly modulate large-EPP generating ending potentiation, and small-EPP generating ending depression through their association with the calcium channels during development. © 2003 IBRO. Published by Elsevier Ltd. All rights reserved. Fil:Uchitel, O.D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2004 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03064522_v123_n1_p61_Santafe http://hdl.handle.net/20.500.12110/paper_03064522_v123_n1_p61_Santafe |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Cholinergic synapse Motor endplate Motor nerve terminal Polyneuronal innervation Voltage-dependent calcium channels acetylcholine calcium calcium channel calcium channel L type calcium channel N type calcium channel P type calcium channel Q type methoctramine muscarinic M1 receptor antagonist muscarinic M2 receptor antagonist muscarinic M4 receptor muscarinic receptor muscarinic receptor blocking agent otenzepad pirenzepine tropicamide acetylcholine release animal experiment animal tissue article controlled study drug effect endplate potential innervation intracellular recording neuromuscular synapse neurotransmitter release nonhuman priority journal rat |
| spellingShingle |
Cholinergic synapse Motor endplate Motor nerve terminal Polyneuronal innervation Voltage-dependent calcium channels acetylcholine calcium calcium channel calcium channel L type calcium channel N type calcium channel P type calcium channel Q type methoctramine muscarinic M1 receptor antagonist muscarinic M2 receptor antagonist muscarinic M4 receptor muscarinic receptor muscarinic receptor blocking agent otenzepad pirenzepine tropicamide acetylcholine release animal experiment animal tissue article controlled study drug effect endplate potential innervation intracellular recording neuromuscular synapse neurotransmitter release nonhuman priority journal rat Uchitel, Osvaldo Daniel Muscarinic autoreceptors related with calcium channels in the strong and weak inputs at polyinnervated developing rat neuromuscular junctions |
| topic_facet |
Cholinergic synapse Motor endplate Motor nerve terminal Polyneuronal innervation Voltage-dependent calcium channels acetylcholine calcium calcium channel calcium channel L type calcium channel N type calcium channel P type calcium channel Q type methoctramine muscarinic M1 receptor antagonist muscarinic M2 receptor antagonist muscarinic M4 receptor muscarinic receptor muscarinic receptor blocking agent otenzepad pirenzepine tropicamide acetylcholine release animal experiment animal tissue article controlled study drug effect endplate potential innervation intracellular recording neuromuscular synapse neurotransmitter release nonhuman priority journal rat |
| description |
Using intracellular recording, we studied how several muscarinic antagonists affected the evoked endplate potentials in singly and dually innervated endplates of the levator auris longus muscle from 3 to 6-day-old rats. In dually innervated fibers, a second endplate potential (EPP) may appear after the first one when we increase the stimulation intensity. The lowest and highest EPP amplitudes are designated "small-EPP" and "large-EPP," respectively. In singly innervated endplates and large-EPP, we found an inhibition of acetylcholine release by M1-receptor antagonists pirenzepine and MT-7 (more than 30%) and M2-receptor antagonists methoctramine and AF-DX 116 (more than 40%). The small-EPP was also inhibited by both M2-receptor antagonists methoctramine (approximately 70%) and AF-DX 116 (approximately 40%). However, the small-EPP was enhanced by M1-receptor antagonists pirenzepine (approximately 90%) and MT-7 (approximately 50%). The M4-receptor selective antagonists tropicamide and MT-3 can also increase the small-EPP amplitude (75% and 120%, respectively). We observed a graded change from a multichannel involvement (P/Q- N- and L-type voltage-dependent calcium channels) of all muscarinic responses (M1-, M2- and M4-mediated) in the small-EPP to the single channel (P/Q-type) involvement of the M1 and M2 responses in the singly innervated endplates. This indicates the existence of a progressive calcium channels shutoff in parallel with the specialization of the adult type P/Q channel. In conclusion, muscarinic autoreceptors can directly modulate large-EPP generating ending potentiation, and small-EPP generating ending depression through their association with the calcium channels during development. © 2003 IBRO. Published by Elsevier Ltd. All rights reserved. |
| author |
Uchitel, Osvaldo Daniel |
| author_facet |
Uchitel, Osvaldo Daniel |
| author_sort |
Uchitel, Osvaldo Daniel |
| title |
Muscarinic autoreceptors related with calcium channels in the strong and weak inputs at polyinnervated developing rat neuromuscular junctions |
| title_short |
Muscarinic autoreceptors related with calcium channels in the strong and weak inputs at polyinnervated developing rat neuromuscular junctions |
| title_full |
Muscarinic autoreceptors related with calcium channels in the strong and weak inputs at polyinnervated developing rat neuromuscular junctions |
| title_fullStr |
Muscarinic autoreceptors related with calcium channels in the strong and weak inputs at polyinnervated developing rat neuromuscular junctions |
| title_full_unstemmed |
Muscarinic autoreceptors related with calcium channels in the strong and weak inputs at polyinnervated developing rat neuromuscular junctions |
| title_sort |
muscarinic autoreceptors related with calcium channels in the strong and weak inputs at polyinnervated developing rat neuromuscular junctions |
| publishDate |
2004 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03064522_v123_n1_p61_Santafe http://hdl.handle.net/20.500.12110/paper_03064522_v123_n1_p61_Santafe |
| work_keys_str_mv |
AT uchitelosvaldodaniel muscarinicautoreceptorsrelatedwithcalciumchannelsinthestrongandweakinputsatpolyinnervateddevelopingratneuromuscularjunctions |
| _version_ |
1768542037939847168 |