Faculty Opinions recommendation of Compound vesicle fusion increases quantal size and potentiates synaptic transmission.

Hsia, Albert Y., Robert C. Malenka, and Roger A. Nicoll. Development of excitatory circuitry in the hippocampus. J. Neurophysiol. 79: 2013–2024, 1998. Assessing the development of local circuitry in the hippocampus has relied primarily on anatomic studies. Here we take a physiological approach, to directly evaluate the means by which the mature state of connectivity between CA3 and CA1 hippocampal pyramidal cells is established. Using a technique of comparing miniature excitatory postsynaptic currents (mEPSCs) to EPSCs in response to spontaneously occurring action potentials in CA3 cells, we found that from neonatal to adult ages, functional synapses are created and serve to increase the degree of connectivity between CA3-CA1 cell pairs. Neither the probability of release nor mean quantal size was found to change significantly with age. However, the variability of quantal events decreases substantially as synapses mature. Thus in the hippocampus the developmental strategy for enhancing excitatory synaptic transmission does not appear to involve an increase in the efficacy at individual synapses, but rather an increase in the connectivity between cell pairs.

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SNARE Force Synchronizes Synaptic Vesicle Fusion and Controls the Kinetics of Quantal Synaptic Transmission

Journal of Neuroscience ◽

10.1523/jneurosci.1551-10.2010 ◽

2010 ◽

Vol 30 (31) ◽

pp. 10272-10281 ◽

Cited By ~ 30

Author(s):

R. E. Guzman ◽

Y. N. Schwarz ◽

J. Rettig ◽

D. Bruns

Keyword(s):

Synaptic Transmission ◽

Synaptic Vesicle ◽

Vesicle Fusion ◽

Synaptic Vesicle Fusion ◽

Kinetics Of

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Eye opening differentially modulates inhibitory synaptic transmission in the developing visual cortex

10.1101/199661 ◽

2017 ◽

Author(s):

Wuqiang Guan ◽

Jun-Wei Cao ◽

Lin-Yun Liu ◽

Zhi-Hao Zhao ◽

Yinghui Fu ◽

...

Keyword(s):

Visual Cortex ◽

Synaptic Transmission ◽

Animal Development ◽

Quantal Size ◽

Excitatory Neurons ◽

Artificial Opening ◽

Eye Opening ◽

Fast Spiking ◽

And Function ◽

Mouse Visual Cortex

AbstractEye opening, a natural and timed event during animal development, influences cortical circuit assembly and maturation; yet, little is known about its precise effect on inhibitory synaptic connections. Here we show that coinciding with eye opening, the strength of unitary inhibitory postsynaptic currents (uIPSCs) from somatostatin-expressing interneurons (SST-INs) to nearby excitatory neurons, but not interneurons, sharply decreases in layer 2/3 of the mouse visual cortex. In contrast, the strength of uIPSCs from fast-spiking interneurons (FS-INs) to excitatory neurons significantly increases during eye opening. More importantly, these developmental changes can be prevented by dark rearing or binocular lid suture, and reproduced by artificial opening of sutured lids. Mechanistically, this differential maturation of synaptic transmission is accompanied by a significant change in the postsynaptic quantal size. Together, our study reveals a differential regulation in GABAergic circuits in the cortex driven by eye opening likely crucial for cortical maturation and function.

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Presynaptic control of quantal size: kinetic mechanisms and implications for synaptic transmission and plasticity

Current Opinion in Neurobiology ◽

10.1016/s0959-4388(03)00078-3 ◽

2003 ◽

Vol 13 (3) ◽

pp. 324-331 ◽

Cited By ~ 40

Author(s):

Guosong Liu

Keyword(s):

Synaptic Transmission ◽

Quantal Size ◽

Kinetic Mechanisms ◽

Presynaptic Control

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Quantal synaptic transmission in phrenic motor nucleus

Journal of Neurophysiology ◽

10.1152/jn.1992.68.4.1468 ◽

1992 ◽

Vol 68 (4) ◽

pp. 1468-1471 ◽

Cited By ~ 19

Author(s):

G. Liu ◽

J. L. Feldman

Keyword(s):

Spinal Cord ◽

Synaptic Transmission ◽

Amplitude Distribution ◽

Excitatory Synaptic Transmission ◽

Neonatal Rat ◽

Respiratory Neurons ◽

Motor Nucleus ◽

Patch Clamp Recording ◽

Epsc Amplitude ◽

Quantal Size

1. The quantal nature of excitatory synaptic transmission was studied in respiratory interneurons and phrenic motoneurons of intact neonatal rat brain stem-spinal cord preparations in vitro. Synaptic currents were recorded with whole-cell patch-clamp recording techniques. 2. Because the most important factor for quantal detection is the ratio of quantal size to quantal standard deviation, factors that influence this ratio were evaluated so that experimental techniques that enhance this ratio could be defined. 3. Under favorable conditions, we directly observed quantal amplitude fluctuations in spontaneous excitatory postsynaptic currents (EPSCs) in spinal cord respiratory neurons. The quantal conductance size was 55-100 pS. With fast decay of these EPSCs, the charge reaching the soma for a single quantum is only approximately 15 fC (Vh = -80 mV). 4. We also studied miniature EPSC amplitude distributions. These were skewed, as previously reported; however, distinct quantal intervals were observed. Furthermore, in three cells tested, the quantal size in the miniature EPSC amplitude distribution was similar to the quantal size in the spontaneous EPSC amplitude distribution. 5. We conclude that excitatory synaptic transmission in the mammalian spinal cord is quantal and that the apparent skewness of miniature EPSC distributions results from summation of events with multiple quantal peak amplitudes.

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Differential effects of tetanus toxin on inhibitory and excitatory synaptic transmission in mammalian spinal cord neurons in culture: a presynaptic locus of action for tetanus toxin

Journal of Neurophysiology ◽

10.1152/jn.1987.57.1.121 ◽

1987 ◽

Vol 57 (1) ◽

pp. 121-131 ◽

Cited By ~ 62

Author(s):

G. K. Bergey ◽

H. Bigalke ◽

P. G. Nelson

Keyword(s):

Spinal Cord ◽

Synaptic Transmission ◽

Tetanus Toxin ◽

Excitatory Synaptic Transmission ◽

Excitatory Postsynaptic Potential ◽

Spinal Neurons ◽

Spinal Cord Neurons ◽

Excitatory Transmission ◽

Quantal Size ◽

Marked Diminution

Tetanus toxin reduces monosynaptic inhibitory and excitatory synaptic transmission in mouse spinal cord neurons in culture. Inhibitory transmission is preferentially reduced by the toxin; however, excitatory transmission is also ultimately reduced and blocked by the concentrations of toxin used in these studies. Recordings from monosynaptically connected cell pairs revealed a marked diminution in amplitude of evoked monosynaptic inhibitory postsynaptic potentials coincident with the onset of convulsant action at a time when evoked monosynaptic EPSPs were relatively unaffected. Increased polysynaptic excitation occurred as a result of diminished inhibition. This supports the reduction of inhibition as an important mechanism in the convulsant action of tetanus toxin. Quantal analysis of the late effects of tetanus toxin on the monosynaptic excitatory postsynaptic potential revealed a reduction in quantal number with no reduction in quantal size, thus demonstrating a presynaptic locus of action for the toxin on spinal neurons.

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