Biomaterial Database

The role of serotonin in non-cholinergic excitatory transmission in the guinea pig inferior mesenteric ganglion. 1990

W Wang, and R C Ma

Department of Physiology, Anhui Medical University, People's Republic of China.

The non-cholinergic late slow excitatory postsynaptic potential (ls-EPSP) of the guinea pig inferior mesenteric ganglion (IMG) was previously believed to be mediated by substance P (SP) or several other neuropeptides. Yet, the pharmacological evidence presented here indicates that serotonin (5-HT) may be another transmitter for the ls-EPSP in the guinea pig IMG. Repetitive stimulation of the presynaptic nerves elicited ls-EPSP in about half of the IMG neurons. Application of 5-HT or SP caused, in a portion of the IMG neurons, a slow depolarization similar to ls-EPSP. Fifty-six out of 88 (63.6%) neurons with ls-EPSP and 13 out of 35 (37.1%) neurons with ls-EPSP were sensitive to 5-HT and SP, respectively. Superfusion of the ganglia with 5-HT markedly suppressed the ls-EPSP evoked in 5-HT sensitive neurons. Similarly, exogenously applied SP attenuated the ls-EPSP of SP-sensitive neurons. However, prolonged superfusion of 5-HT or SP had no effect on the ls-EPSP elicited in 5-HT or SP-insensitive neurons, respectively. Furthermore, the ls-EPSPs elicited in 5-HT-sensitive neurons as well as the 5-HT-induced depolarization were reversibly suppressed by cyproheptadine, a 5-HT antagonist, and enhanced by fluoxetine, a 5-HT reuptake inhibitor. In contrast, the ls-EPSP of 5-HT insensitive neurons and SP-induced depolarization were not appreciably changed by those two drugs. Pretreatment with p-chlorophenylalanine, a 5-HT biosynthesis inhibitor, did not change the general electrophysiological characteristics of the neurons and did not suppress nicotinic neurotransmission, but markedly reduced the occurrence rate of ls-EPSP from 53.8% to 15.1% (P less than 0.005). Collectively, our results indicate that, besides SP, 5-HT may be involved in mediating the ls-EPSP in a subpopulation of neurons in the guinea pig IMG. The type of transmitter mediating ls-EPSP is apparently not limited to 5-HT and SP, as about 30% of the neurons with ls-EPSP were found to be insensitive to both 5-HT and SP and prolonged superfusion with both did not affect appreciably the ls-EPSP elicited in these neurons.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D009197	Myenteric Plexus	One of two ganglionated neural networks which together form the ENTERIC NERVOUS SYSTEM. The myenteric (Auerbach's) plexus is located between the longitudinal and circular muscle layers of the gut. Its neurons project to the circular muscle, to other myenteric ganglia, to submucosal ganglia, or directly to the epithelium, and play an important role in regulating and patterning gut motility. (From FASEB J 1989;3:127-38)	Auerbach's Plexus,Auerbach Plexus,Auerbachs Plexus,Plexus, Auerbach's,Plexus, Myenteric
D009435	Synaptic Transmission	The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.	Neural Transmission,Neurotransmission,Transmission, Neural,Transmission, Synaptic
D003533	Cyproheptadine	A serotonin antagonist and a histamine H1 blocker used as antipruritic, appetite stimulant, antiallergic, and for the post-gastrectomy dumping syndrome, etc.	Antergan,Dihexazin,Periactin,Peritol,Viternum
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D005071	Evoked Potentials	Electrical responses recorded from nerve, muscle, SENSORY RECEPTOR, or area of the CENTRAL NERVOUS SYSTEM following stimulation. They range from less than a microvolt to several microvolts. The evoked potential can be auditory (EVOKED POTENTIALS, AUDITORY), somatosensory (EVOKED POTENTIALS, SOMATOSENSORY), visual (EVOKED POTENTIALS, VISUAL), or motor (EVOKED POTENTIALS, MOTOR), or other modalities that have been reported.	Event Related Potential,Event-Related Potentials,Evoked Potential,N100 Evoked Potential,P50 Evoked Potential,N1 Wave,N100 Evoked Potentials,N2 Wave,N200 Evoked Potentials,N3 Wave,N300 Evoked Potentials,N4 Wave,N400 Evoked Potentials,P2 Wave,P200 Evoked Potentials,P50 Evoked Potentials,P50 Wave,P600 Evoked Potentials,Potentials, Event-Related,Event Related Potentials,Event-Related Potential,Evoked Potential, N100,Evoked Potential, N200,Evoked Potential, N300,Evoked Potential, N400,Evoked Potential, P200,Evoked Potential, P50,Evoked Potential, P600,Evoked Potentials, N100,Evoked Potentials, N200,Evoked Potentials, N300,Evoked Potentials, N400,Evoked Potentials, P200,Evoked Potentials, P50,Evoked Potentials, P600,N1 Waves,N2 Waves,N200 Evoked Potential,N3 Waves,N300 Evoked Potential,N4 Waves,N400 Evoked Potential,P2 Waves,P200 Evoked Potential,P50 Waves,P600 Evoked Potential,Potential, Event Related,Potential, Event-Related,Potential, Evoked,Potentials, Event Related,Potentials, Evoked,Potentials, N400 Evoked,Related Potential, Event,Related Potentials, Event,Wave, N1,Wave, N2,Wave, N3,Wave, N4,Wave, P2,Wave, P50,Waves, N1,Waves, N2,Waves, N3,Waves, N4,Waves, P2,Waves, P50
D005260	Female		Females
D005473	Fluoxetine	The first highly specific serotonin uptake inhibitor. It is used as an antidepressant and often has a more acceptable side-effects profile than traditional antidepressants.	Fluoxetin,Fluoxetine Hydrochloride,Lilly-110140,N-Methyl-gamma-(4-(trifluoromethyl)phenoxy)benzenepropanamine,Prozac,Sarafem,Lilly 110140,Lilly110140
D005728	Ganglia, Sympathetic	Ganglia of the sympathetic nervous system including the paravertebral and the prevertebral ganglia. Among these are the sympathetic chain ganglia, the superior, middle, and inferior cervical ganglia, and the aorticorenal, celiac, and stellate ganglia.	Celiac Ganglia,Sympathetic Ganglia,Celiac Ganglion,Ganglion, Sympathetic,Ganglia, Celiac,Ganglion, Celiac,Sympathetic Ganglion