Electrical and optical study of nerve impulse-evoked ATP-induced, P2X-receptor-mediated sympathetic neurotransmission at single smooth muscle cells in mouse isolated vas deferens
| Autor: | Keith L. Brain, John S. Young, T.C. Cunnane |
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| Jazyk: | angličtina |
| Předmět: |
Male
Time Factors sEJP spontaneous excitatory junction potential SMC smooth muscle cell confocal microscopy Synaptic Transmission chemistry.chemical_compound Mice 0302 clinical medicine Adenosine Triphosphate Vas Deferens EJP excitatory junction potential Neurotransmitter 0303 health sciences Mice Inbred BALB C Neurotransmitter Agents Microscopy Confocal Pulse (signal processing) DE discrete event General Neuroscience Purinergic receptor Vas deferens nNCT number of neuroeffector calcium transients per stimulus per cell Electrophysiology calcium imaging medicine.anatomical_structure NCT Receptors Purinergic P2X Excitatory postsynaptic potential Synaptic Vesicles medicine.medical_specialty Neuroeffector Neuroscience(all) Myocytes Smooth Muscle EJP Presynaptic Terminals Biology Neurotransmission 03 medical and health sciences Organ Culture Techniques Sympathetic Fibers Postganglionic Internal medicine parasitic diseases medicine Animals discrete event Calcium Signaling BAPTA 1 2-bis(o-aminophenoxy)ethane-N N N′ N′-tetraacetic acid MVD mouse vas deferens 030304 developmental biology GPVD guinea-pig vas deferens Receptors Purinergic P2 PSS physiological salt solution Excitatory Postsynaptic Potentials NCT neuroeffector calcium transient Endocrinology chemistry Cellular Neuroscience Biophysics 030217 neurology & neurosurgery |
| Zdroj: | Neuroscience |
| ISSN: | 0306-4522 |
| DOI: | 10.1016/j.neuroscience.2007.05.044 |
| Popis: | Simultaneous electrophysiology and confocal microscopy were used to investigate purinergic neurotransmission at single smooth muscle cells (SMCs) in mouse isolated vas deferens, and to explore the relationship between two high-resolution P2X-receptor-mediated measures of per pulse ATP release: transient peaks in the first time derivative of the rising phase of excitatory junction potentials (EJPs) recorded in single SMCs (‘discrete events’; DEs) and neuroeffector Ca2+ transients (NCTs) in the impaled SMCs. This study shows that discrete events represent neurotransmitter release onto the impaled cell. First, the median amplitude of the first derivative of the EJP was larger when there was a coincident NCT in the impaled cell, compared with instances when no coincident NCT occurred. Second, the time-to-peak amplitude of the first derivative was shorter if there was a coincident NCT in the impaled cell, compared with when no coincident NCT was observed within the field. Surprisingly, first derivative amplitude increased with the distance (of the corresponding NCT) from the microelectrode. The microelectrode did not locally inhibit the functional quantal size as there was no effect of distance on the normalized NCT amplitude. When the significant effect of distance (between the microelectrode and NCTs) on the first derivative amplitude was removed, there was no correlation between the unstandardized residual (of distance vs. first derivative amplitude) and NCT amplitude. The absence of a correlation between DE and NCT amplitudes suggests that the NCT amplitude is a poor measure of quantal size. The usefulness of NCTs hence lies primarily in locating neurotransmitter release and measuring changes in local release probability. |
| Databáze: | OpenAIRE |
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