Related Experiment Video
Updated: Jan 21, 2026
06:32
Quadruple Immunostaining of the Olfactory Bulb for Visualization of Olfactory Sensory Axon Molecular Identity Codes
Published on: June 5, 2017
7.6K
Balancing Extrasynaptic Excitation and Synaptic Inhibition within Olfactory Bulb Glomeruli
David H Gire1,2, Joseph D Zak1,2, Jennifer N Bourne1
1Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, CO 80045.
Eneuro
|July 27, 2019
Summary
Extrasynaptic glutamate receptors in the olfactory bulb mediate feedforward excitation. This excitation strengthens with increased neural firing, potentially enhancing olfactory contrast.
Area of Science:
- Neuroscience
- Olfactory System
- Synaptic Transmission
Background:
- Glutamatergic transmission traditionally occurs at synapses, but extrasynaptic receptor activation is increasingly recognized.
- The olfactory bulb processes sensory information through complex neural circuits.
Purpose of the Study:
- To investigate the mechanisms and function of extrasynaptic glutamate receptor signaling in the olfactory bulb's feedforward pathway.
- To elucidate the dynamics of extrasynaptic excitation and its interplay with inhibition.
Main Methods:
- Pair-cell and triple-cell recordings in rat olfactory bulb slices.
- Ultrastructural analysis.
- Assaying neural excitation and inhibition in response to varying stimulus strengths.
Main Results:
- External tufted cell (eTC) to mitral cell (MC) signaling involves glutamate spillover, co-occurring with inhibition of periglomerular (PG) cells.
- Extrasynaptic MC excitation is weak with single spikes but increases supralinearly with higher firing rates.
- Synaptic PG cell excitation shows sublinear behavior.
- The balance of excitation and inhibition shifts with stimulus magnitude.
Conclusions:
- Extrasynaptic signaling in the olfactory bulb is a dynamic process influenced by neural firing rates.
- The interplay between extrasynaptic excitation and inhibition provides an intraglomerular mechanism for olfactory contrast enhancement.
Related Concept Videos
01:12Synaptic Signaling
79.2K
Neurons communicate at synapses, or junctions, to excite or inhibit the activity of other neurons or target cells, such as muscles. Synapses may be chemical or electrical.
79.2K
01:09Synaptic Signaling
6.6K
Neurons communicate at synapses, or junctions, to excite or inhibit the activity of other neurons or target cells, such as muscles. Synapses may be chemical or electrical.
Most synapses are chemical, meaning an electrical impulse or action potential spurs the release of chemical messengers called neurotransmitters. The neuron sending the signal is called the presynaptic neuron, and the neuron receiving the signal is the postsynaptic neuron.
The presynaptic neuron fires an action potential that...
Most synapses are chemical, meaning an electrical impulse or action potential spurs the release of chemical messengers called neurotransmitters. The neuron sending the signal is called the presynaptic neuron, and the neuron receiving the signal is the postsynaptic neuron.
The presynaptic neuron fires an action potential that...
6.6K
02:58Balancing Redox Equations
61.7K
Electrochemistry is the science involved in the interconversion of electrical and chemical reactions. Such reactions are called reduction-oxidation, or redox reactions. These important reactions are defined by changes in oxidation states for one or more reactant elements and include a subset of reactions involving the transfer of electrons between reactant species. Electrochemistry as a field has evolved to yield sufficient insights on the fundamental principles of redox chemistry and multiple...
61.7K
00:46Feedback Inhibition
56.9K
Biochemical reactions are occurring constantly in cells, converting starting substances to different products, usually with the help of enzymes that speed the reactions. Without enzymes, it would take far too long for most reactions to occur to be useful to the cell!
56.9K
01:19Energy Balance
1.2K
The human body gets energy from the three macronutrients: carbohydrates, proteins, and fats. Energy is released when the chemical bonds in the organic compounds present in the food are broken down. The energy content of food is measured in kilocalories (kcal), defined as the amount of heat required to raise the temperature of one kilogram of water by one degree Celsius. This value is determined by measuring the temperature change of the water surrounding a calorimeter after the complete...
1.2K
01:15Equilibrium and Balance
6.4K
The inner ear assumes dual functionalities of auditory perception and equilibrium maintenance. The vestibule is the organ responsible for balance. This organ contains mechanoreceptors, specifically hair cells, endowed with stereocilia, which aid in deciphering information regarding the position and motion of our heads. Two intrinsic components, the utricle and saccule, help perceive head position, while the semicircular canals track head movement. Neurological messages initiated in the...
6.4K