Related Experiment Video
Updated: Jan 21, 2026
08:46
Studying Synaptic Vesicle Pools using Photoconversion of Styryl Dyes
Published on: February 15, 2010
12.1K
5-HT3R-sourced calcium enhances glutamate release from a distinct vesicle pool
Jessica A Fawley1, Mark W Doyle1, Michael C Andresen1
1Department of Physiology & Pharmacology, Oregon Health & Science University, Portland, OR, USA.
Brain Research
|July 27, 2019
Summary
The serotonin 3 receptor (5-HT3R) influences glutamate release in the brainstem. Activation of 5-HT3Rs mobilizes spontaneous release and affects signal conduction, suggesting distinct roles in synaptic signaling.
Area of Science:
- Neuroscience
- Cellular and Molecular Biology
- Neuropharmacology
Background:
- The serotonin 3 receptor (5-HT3R) is a calcium-permeant channel found on solitary tract (ST) afferents.
- ST afferents utilize voltage-dependent calcium channels (CaVs) for synchronous glutamate release (ST-EPSCs) and asynchronous EPSCs, particularly in TRPV1-expressing neurons.
- Spontaneous glutamate release (sEPSCs) in most afferents is independent of CaVs.
Purpose of the Study:
- To investigate the role of 5-HT3R-mediated calcium influx in different forms of glutamate release from ST afferents in rat NTS slices.
- To determine if 5-HT3R activation affects ST-EPSCs, asynchronous EPSCs, and sEPSCs.
Main Methods:
- Electrophysiological recordings in horizontal NTS slices from rats.
- Application of the selective 5-HT3R agonist m-chlorophenyl biguanide hydrochloride (PBG).
- Application of the selective 5-HT3R antagonist ondansetron.
- Calcium chelation experiments using EGTA-AM.
Main Results:
- PBG enhanced sEPSCs and increased ST-EPSC latency, indicating 5-HT3R activation.
- Ondansetron reversed PBG-induced effects, confirming 5-HT3R involvement.
- PBG did not affect ST-EPSC amplitude or asynchronous EPSCs, suggesting distinct 5-HT3R locations (axonal and terminal).
- Calcium chelation reduced the frequency of 5-HT3R-activated sEPSCs, indicating involvement of both micro- and nanodomain calcium sources.
Conclusions:
- 5-HT3Rs contribute uniquely to glutamate release by mobilizing spontaneous vesicle pools and modulating signal conduction.
- The calcium domains of 5-HT3Rs are independent of other calcium sources and their associated vesicle pools.
- 5-HT3Rs represent a novel calcium source involved in multiple, independent synaptic signaling mechanisms in ST afferents.
Related Concept Videos
01:045-Number Summary
5.5K
In a dataset, the 5-number summary includes the minimum data value, the data value of the first quartile, the median data value or data value of the second quartile, the data value of the third quartile, and the maximum data value. These 5 data values can be visualized as a box and whisker plot.
In a box plot, the minimum and maximum data values represent the lower and upper whiskers in the graph, and the median is designated as the center of the box in the chart. The first quartile and third...
In a box plot, the minimum and maximum data values represent the lower and upper whiskers in the graph, and the median is designated as the center of the box in the chart. The first quartile and third...
5.5K
01:14Antiepileptic Drugs: Glutamate Antagonists
914
Glutamate is a fundamental neurotransmitter in the central nervous system, playing a vital role in neuronal communication and various cognitive processes. Glutamate stands as the principal excitatory neurotransmitter in the brain. Its presence is crucial for the communication between neurons, underpinning essential processes such as synaptic transmission, neuronal excitability, and plasticity. These functions are vital for higher-order cognitive processes, including learning and memory. The...
914
01:28Energy-releasing Steps of Glycolysis
146.4K
Glycolysis is divided into two phases based on whether energy is utilized or released. While the first phase consumes ATP, the second phase produces energy in the form of ATP and NADH. The energy is released over a sequence of reactions that turns G3P into pyruvate. The energy-releasing phase—steps 6-10 of glycolysis—occurs twice, once for each of the two 3-carbon sugars produced during steps 1-5 of the first phase.
The first energy-releasing step—the 6th step of glycolysis...
The first energy-releasing step—the 6th step of glycolysis...
146.4K
03:00Self-Evaluation: Self-Enhancement and Self-Verification
5.7K
Social psychologists have documented that feeling good about ourselves and maintaining positive self-esteem is a powerful motivator of human behavior (Tavris & Aronson, 2008). In the United States, members of the predominant culture typically think very highly of themselves and view themselves as good people who are above average on many desirable traits (Ehrlinger, Gilovich, & Ross, 2005). Often, our behavior, attitudes, and beliefs are affected when we experience a threat to our...
5.7K
01:18Sinusoidal Sources
1.1K
Direct current (DC) refers to an electric current that flows in a single direction, maintaining a constant polarity. This is in contrast to alternating current (AC), which periodically changes its direction and magnitude. AC forms the backbone of modern electricity transmission and distribution systems due to its efficient long-distance transmission capabilities.
In homes, the power supplies use sinusoidal sources to provide electricity. These sources generate a voltage that varies sinusoidally...
In homes, the power supplies use sinusoidal sources to provide electricity. These sources generate a voltage that varies sinusoidally...
1.1K
01:15Source Transformation
11.2K
Source transformation is a fundamental technique employed in circuit analysis, offering a valuable tool for simplifying complex electrical circuits. This technique involves the replacement of either a voltage source in series with a resistor by a current source in parallel with a resistor, or vice versa. The key concept here is that when the original sources are deactivated (turned off), the equivalent resistance at the circuit's end terminals remains the same.
It is essential to note that when...
It is essential to note that when...
11.2K