Modern aspects in the studies of inhibitory synaptic transmission in the central nervous system of mammals

1998 ◽  
Vol 30 (4-5) ◽  
pp. 199-199
Author(s):  
N. S. Veselovskii ◽  
S. S. Fedulova ◽  
D. V. Vasil'ev ◽  
E. V. Isaeva
2020 ◽  
Author(s):  
Chungwon Park ◽  
Xingxiang Chen ◽  
Chong-Li Tian ◽  
Gyu Nam Park ◽  
Nicolas Chenouard ◽  
...  

AbstractMaintaining the balance between neuronal excitation and inhibition is essential for proper function of the central nervous system, with inhibitory synaptic transmission playing an important role. Although inhibitory transmission has higher kinetic demands compared to excitatory transmission, its properties are poorly understood. In particular, the dynamics and exocytosis of single inhibitory vesicles have not been investigated, due largely to both technical and practical limitations. Using a combination of quantum dots (QDs) conjugated to antibodies against the luminal domain of the vesicular GABA transporter (VGAT) to selectively label GABAergic (i.e., inhibitory) vesicles together with dual-focus imaging optics, we tracked the real-time three-dimensional position of single inhibitory vesicles up to the moment of exocytosis (i.e., fusion). Using three-dimensional trajectories, we found that inhibitory synaptic vesicles traveled a short distance prior to fusion and had a shorter time to fusion compared to synaptotagmin-1 (Syt1)-labeled vesicles, which were mostly from excitatory neurons. Moreover, our analysis revealed a close correlation between the release probability of inhibitory vesicles and both the proximity to their fusion site and the total travel length. Finally, we found that inhibitory vesicles have a higher prevalence of kiss-and-run fusion compared than Syt1-labeled vesicles. These results indicate that inhibitory synaptic vesicles have a unique set of dynamics and fusion properties to support rapid synaptic inhibition, thereby maintaining a tightly regulated balance between excitation and inhibition in the central nervous system.SignificanceDespite playing an important role in maintaining brain function, the dynamics of inhibitory synaptic vesicles are poorly understood. Here, we tracked the three-dimensional position of single inhibitory vesicles up to the moment of exocytosis in real time by loading single inhibitory vesicle with QDs-conjugated to antibodies against the luminal domain of the vesicular GABA transporter (VGAT). We found that inhibitory synaptic vesicles have a smaller total travel length before fusion, a shorter fusion time, and a higher prevalence of kiss-and-run than synaptotagmin-1-lableled vesicles. Our findings provide the first evidence that inhibitory vesicles have a unique set of dynamics and exocytosis properties to support rapid inhibitory synaptic transmission.


1976 ◽  
Vol 4 (3) ◽  
pp. 199-202 ◽  
Author(s):  
T. A. Torda ◽  
P. W. Gage

Thiopentone and pentobarbitone reduce the time constant of decay of miniature end-plate currents when applied in anaesthetic concentrations to the neuromuscular junction. Such an effect at central synapses would lead to failure of synaptic transmission in the central nervous system and may reflect a common mode of action of many anaesthetic drugs.


1958 ◽  
Vol 192 (3) ◽  
pp. 447-452 ◽  
Author(s):  
Sadayuki F. Takagi ◽  
Yutaka Oomura

The effect of nicotine on synaptic transmission in the frog and cat spinal cord was studied. Both a regular wick electrode and a microelectrode of the Ling-Gerard type were used. The reflex activity of the bullfrog spinal cord is facilitated by 0.01% nicotine solution, but is depressed and abolished by 0.1% solution. In the cat, intravenous administration of 150 mg/kg fails to block reflex activity, but topical application does block. The intracellular potential, of both frog and cat motoneurones, shows no change in the synaptic potential after application of the drug, but the spike appears after a shorter synaptic delay and one or more additional spikes appear. When the synaptic delay becomes sufficiently short, however, all spikes suddenly disappear, leaving the still unchanged synaptic potential. Occasionally the synaptic delay is again increased just before the spike potentials disappear. The excitability of a frog motoneurone was measured, by a recording microelectrode, before and after nicotine application. The drug first increased and then decreases excitability. Epinephrine can restore a reflex discharge depressed or abolished by nicotine. It is concluded that high concentrations of nicotine block synaptic transmission in the central nervous system, acting on the cell body but not on the synaptic potential.


Physiology ◽  
1996 ◽  
Vol 11 (4) ◽  
pp. 161-166
Author(s):  
H Ohmori

Hair cells transduce mechanical information into electrical signal and, via afferent synapse, transmit it to the central nervous system (CNS). Hair cells receive cholinergic efferent innervation from the CNS, and a long-lasting membrane hyperpolarization is produced by activation of Ca2+-activated K+ channels. Acetylcholine may facilitate afferent synaptic transmission by suppressing K+ channels on the afferent nerve terminal.


2010 ◽  
Vol 38 (6) ◽  
pp. 1527-1530 ◽  
Author(s):  
Joel D. Richter

Synapses, points of contact between axons and dendrites, are conduits for the flow of information in the circuitry of the central nervous system. The strength of synaptic transmission reflects the interconnectedness of the axons and dendrites at synapses; synaptic strength in turn is modified by the frequency with which the synapses are stimulated. This modulation of synaptic strength, or synaptic plasticity, probably forms the cellular basis for learning and memory. RNA metabolism, particularly translational control at or near the synapse, is one process that controls long-lasting synaptic plasticity and, by extension, memory formation and consolidation. In the present paper, I review some salient features of translational control of synaptic plasticity.


2020 ◽  
Vol 18 (10) ◽  
pp. 936-965
Author(s):  
Xuechao Hao ◽  
Mengchan Ou ◽  
Donghang Zhang ◽  
Wenling Zhao ◽  
Yaoxin Yang ◽  
...  

General anesthetics are a class of drugs that target the central nervous system and are widely used for various medical procedures. General anesthetics produce many behavioral changes required for clinical intervention, including amnesia, hypnosis, analgesia, and immobility; while they may also induce side effects like respiration and cardiovascular depressions. Understanding the mechanism of general anesthesia is essential for the development of selective general anesthetics which can preserve wanted pharmacological actions and exclude the side effects and underlying neural toxicities. However, the exact mechanism of how general anesthetics work is still elusive. Various molecular targets have been identified as specific targets for general anesthetics. Among these molecular targets, ion channels are the most principal category, including ligand-gated ionotropic receptors like γ-aminobutyric acid, glutamate and acetylcholine receptors, voltage-gated ion channels like voltage-gated sodium channel, calcium channel and potassium channels, and some second massager coupled channels. For neural functions of the central nervous system, synaptic transmission is the main procedure for which information is transmitted between neurons through brain regions, and intact synaptic function is fundamentally important for almost all the nervous functions, including consciousness, memory, and cognition. Therefore, it is important to understand the effects of general anesthetics on synaptic transmission via modulations of specific ion channels and relevant molecular targets, which can lead to the development of safer general anesthetics with selective actions. The present review will summarize the effects of various general anesthetics on synaptic transmissions and plasticity.


The tracheal supply to the central nervous system of the locust has been revealed by staining with cobalt sulphide. Air that enters through the first pair of thoracic spiracles is carried first to the brain and then to the rest of the central nervous system. The air is expelled through the abdominal spiracles, so that there is a one-way circulation with diffusional exchange only in the blindly ending tracheae that enter the brain or ganglia. Once inside a ganglion, the tracheae branch profusely to end in a mass of fine tracheoles through which gaseous exchange takes place. The densest tracheation is in the neuropile areas, where the spacing between tracheoles is about 17 μm. In the optic lobes, where there is order to the synaptic arrangement of a neuropile, there is a matching orderliness of the tracheation. Cortical areas, which contain the cell bodies of neurons, have only a sparse tracheation. It may be concluded that it is the processes associated with synaptic transmission that require the most immediate access to the sites of gaseous exchange.


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