Tonic Glutamate
Tonic Glutamate - Related Videos
10:46
Using Enzyme-based Biosensors to Measure Tonic and Phasic Glutamate in Alzheimer's Mouse Models
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Cited by 15 •
2017
Here, we describe the setup, software navigation, and data analysis for a spatially and temporally precise method of measuring tonic and phasic extracellular glutamate changes in vivo using enzyme-linked microelectrode arrays (MEA).
00:59
Tonicity in Animals
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2026
The tonicity of a solution determines if a cell gains or loses water in that solution. The tonicity depends on the permeability of the cell membrane for different solutes and the concentration of nonpenetrating solutes in the solution within and outside of the cell. If a semipermeable membrane hinders the passage of some solutes but allows water to follow its concentration gradient, water moves from the side with low osmolarity (i.e., less solute) to the side with higher osmolarity (i.e.,...
01:16
Tonicity in Animals
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2023
Tonicity describes the amount of solute in a solution. The measure of the tonicity of a solution, or the total amount of solutes dissolved in a specific amount of solution, is called its osmolarity. Three terms—hypotonic, isotonic, and hypertonic—are used to relate the osmolarity of a cell to the osmolarity of the extracellular fluid that contains the cells. In a hypotonic solution, such as tap water, the extracellular fluid has a lower concentration of solutes than the fluid inside the cell,...
00:53
Tonicity in Plants
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2026
Tonicity describes the capacity of a cell to lose or gain water. It depends on the quantity of solute that does not penetrate the membrane. Tonicity delimits the magnitude and direction of osmosis and results in three possible scenarios that alter the volume of a cell: hypertonicity, hypotonicity, and isotonicity. Due to differences in structure and physiology, tonicity of plant cells is different from that of animal cells in some scenarios.Plants and Hypotonic EnvironmentsUnlike animal cells,...
01:20
Tonicity in Plants
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2025
Plant cells maintain appropriate osmotic balance in extreme conditions. For instance, plants in dry environments store water in vacuoles, limit the opening of their stoma, and have thick, waxy cuticles to prevent unnecessary water loss. Some species of plants that live in salty environments store salt in their roots. As a result, water osmosis occurs in the root from the surrounding soil. Tonicity Tonicity describes the capacity of a cell to lose or gain water depending on the solute...
FAQs
The extracellular level reflects a balance between ongoing glutamate release, spillover from nearby signaling sites, and removal by transporters on neurons and glial cells. Continuous release and spillover add glutamate, whereas transporter activity limits its persistence and concentration. Changes in this balance alter how strongly glutamate can influence receptors and shape background excitatory signaling.
Glutamate remaining outside tightly confined synaptic sites can reach extrasynaptic NMDA and AMPA receptors, extending its influence beyond brief synaptic events. Activation of these receptor populations provides a route through which ambient glutamate can affect ongoing excitatory signaling. This mechanism helps connect extracellular glutamate levels with baseline network excitability and changes in synaptic function.
Transporters on both neurons and glial cells restrict the concentration and duration of extracellular glutamate. By clearing glutamate from the surrounding space, they limit continued receptor activation and help prevent excessive excitatory signaling. If clearance is disrupted, ambient glutamate may rise, increasing the possibility of excitotoxicity and making transporter regulation an important focus of neuroscience research.
Tonic glutamate creates an extracellular signal that is shaped jointly by neuronal release and glial uptake. Because glial transporters help regulate how much glutamate remains available, glial activity can influence receptor stimulation outside brief synaptic events. Studying this interaction clarifies how neurons and glia jointly control excitatory conditions and network behavior.
Investigating tonic glutamate helps explain how neural circuits maintain baseline excitability between discrete synaptic events. It also provides context for understanding synaptic plasticity, the process by which synaptic function changes, and communication between neurons and glial cells. These outcomes make ambient glutamate relevant to broader questions about how circuit activity is regulated over time.
These conditions are relevant because disrupted glutamate clearance or excessive ambient glutamate can promote excitotoxicity, a harmful consequence of excessive excitatory signaling. Research on tonic glutamate therefore examines how extracellular regulation may contribute to abnormal or damaging neural activity. The topic connects basic mechanisms of glutamate handling with disease-focused studies across several neurological conditions.
Potential therapeutic approaches center on controlling the processes that determine extracellular glutamate action. Researchers can consider strategies that target glutamate transport or receptor signaling, because both influence how strongly remaining glutamate affects neural circuits. This framework supports investigation of ways to limit excessive excitatory effects while preserving the signaling required for normal neuronal communication.