Learning by Tension

2007 ◽  
Author(s):  
Shengyuan Yang ◽  
Scott Siechen ◽  
Jie Sun ◽  
Akira Chiba ◽  
Taher Saif
Keyword(s):  
Nervous System ◽  
Synaptic Vesicles ◽  
Fruit Fly ◽  
Basic Mechanism ◽  
Drosophila Embryo ◽  
Mems Sensors ◽  
Mechanical Tension ◽  
Memory And Learning ◽  
Synaptic Junctions ◽  
Signaling Process

Memory and learning in animals is mediated by neurotransmission at the synaptic junctions (end point of axons). Neurotransmitters are carried by synaptic vesicles which cluster at the junctions, ready to be dispatched for transmission. The more a synapse is used, higher is the clustering, and higher is the neurotransmission efficiency (plasticity), i.e., the junction “remembers” its use in the near past, and modifies accordingly. This usage dependent plasticity offers the basic mechanism of memory and learning. A central dogma in neuroscience is that, clustering is the result of a complex biochemical signaling process. We show, using MEMS sensors and fruit fly (Drosophila) embryo nervous system, that mechanical tension in axons is essential for clustering. Without tension, clustering disappears, but reappears with application of tension. Nature maintains a rest tension of 1nN in axons of Drosophila for learning and memory.

The Lateral Giant Fiber to Motor Giant Fiber Synapse in Crayfish

1972 ◽  
Vol 30 ◽  
pp. 170-171
Author(s):  
Charles A. Stirling
Keyword(s):  
Synaptic Vesicles ◽  
Procambarus Clarkii ◽  
Synaptic Contact ◽  
Giant Fiber ◽  
Synaptic Junctions

The lateral giant (LG) to motor giant (MoG) synapses in crayfish (Procambarus clarkii) abdominal ganglia are the classic electrotonic synapses. They have previously been described as having synaptic vesicles and as having them on both the pre- and postsynaptic sides of symmetrical synaptic junctions. This positioning of vesicles would make these very atypical synapses, but in the present work on the crayfish Astacus pallipes the motor giant has never been found to contain any type of vesicle at its synapses with the lateral giant fiber.The lateral to motor giant fiber synapses all occur on short branches off the main giant fibers. Closely associated with these giant fiber synapses are two small presynaptic nerves which make synaptic contact with both of the giant fibers and with their small branches.

Substance P: localization in synaptic vesicles in rat central nervous system

1977 ◽  
Vol 29 (4) ◽  
pp. 747-751 ◽  
Author(s):  
A. C. CUELLO ◽  
T. M. JESSELL ◽  
I. KANAZAWA ◽  
L. L. IVERSEN
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Substance P ◽  
Synaptic Vesicles

scholarly journals Cellubrevin and synaptobrevins: similar subcellular localization and biochemical properties in PC12 cells.

1995 ◽  
Vol 129 (1) ◽  
pp. 219-231 ◽  
Author(s):  
T J Chilcote ◽  
T Galli ◽  
O Mundigl ◽  
L Edelmann ◽  
P S McPherson ◽  
...  
Keyword(s):  
Nervous System ◽  
Pc12 Cells ◽  
Transferrin Receptor ◽  
Synaptic Vesicles ◽  
Biochemical Properties ◽  
Similar Distribution ◽  
Similar Function ◽  
High Concentration ◽  
Velocity Gradients ◽  
Dense Core Granules

There is strong evidence to indicate that proteins of the synaptobrevin family play a key role in exocytosis. Synaptobrevin 1 and 2 are expressed at high concentration in brain where they are localized on synaptic vesicles. Cellubrevin, a very similar protein, has a widespread tissue distribution and in fibroblasts is localized on endosome-derived, transferin receptor-positive vesicles. Since brain cellubrevin is not detectable in synaptic vesicles, we investigated whether cellubrevin and the synaptobrevins are differentially targeted when co-expressed in the same cell. We report that in the nervous system cellubrevin is expressed at significant levels only by glia and vascular cells. However, cellubrevin is coexpressed with the two synaptobrevins in PC12 cells, a neuroendocrine cell line which contains synaptic vesicle-like microvesicles. In PC12 cells, cellubrevin has a distribution very similar to that of synaptobrevin 1 and 2. The three proteins are targeted to neurites which exclude the transferrin receptor and are enriched in synaptic-like microvesicles and dense-core granules. They are recovered in the synaptic-like microvesicle peak of glycerol velocity gradients, have a similar distribution in isopycnic fractionation and are coprecipitated by anti-synaptobrevin 2 immunobeads. Finally, cellubrevin, like the synaptobrevins, interact with the neuronal t-SNAREs syntaxin 1 and SNAP-25. These results suggest that cellubrevin and the synaptobrevins have similar function and do not play a specialized role in constitutive and regulated exocytosis, respectively.

scholarly journals Stochastic, structural and functional factors influencing AMPA and NMDA synaptic response variability: a review

2017 ◽  
Vol 1 (3) ◽  
Author(s):  
Vito Di Maio ◽  
Francesco Ventriglia ◽  
Silvia Santillo
Keyword(s):  
Nervous System ◽  
Synaptic Transmission ◽  
Learning And Memory ◽  
Information Transfer ◽  
Basic Mechanism ◽  
Response Variability ◽  
Synaptic Response ◽  
Factors Influencing ◽  
Functional Factors ◽  
The Brain

Synaptic transmission is the basic mechanism of information transfer between neurons not only in the brain, but along all the nervous system. In this review we will briefly summarize some of the main parameters that produce stochastic variability in the synaptic response. This variability produces different effects on important brain phenomena, like learning and memory, and, alterations of its basic factors can cause brain malfunctioning.

Optical Mesurements of Presynaptic Function: What Keeps Vesicle Traffic Going

1998 ◽  
Vol 4 (S2) ◽  
pp. 1020-1021
Author(s):  
Timothy A. Ryan
Keyword(s):  
Nervous System ◽  
Synaptic Vesicles ◽  
Hippocampal Neurons ◽  
Brain Cells ◽  
Membrane Recycling ◽  
Large Collection ◽  
Vesicle Traffic ◽  
Presynaptic Function ◽  
Average Total Number ◽  
Chemical Synapses

The nervous system has evolved to make use of a variety of mechanisms that allow information to flow and be processed among a large collection of individual cells. The communication between individual brain cells occurs largely at chemical synapses. In these compartments, chemical messengers are packaged into small vesicles that fuse with the cell membrane upon stimulation, releasing neurotransmitter.. The average total number of synaptic vesicles in a typical central nervous system synapse is only a few hundred and as a result an efficient local recycling mechanism operates in order to replenish this pool during periods of even modest neuronal activity. Without this membrane recycling, synapses quickly become depleted of vesicles, and soon fail to communicate information between cells.We make use of optical techniques to follow the trafficking of synaptic vesicles at synapses formed between hippocampal neurons grown in culture. Recycling synaptic vesicles can be readily labeled using the fluorescent amphipathic membrane dye FM 1-43.

Edward George Gray. 11 January 1924 – 14 August 1999

2002 ◽  
Vol 48 ◽  
pp. 151-165
Author(s):  
R.W. Guillery
Keyword(s):  
Nervous System ◽  
Three Dimensional ◽  
Electron Microscopic ◽  
Early Application ◽  
Microscopic Appearance ◽  
Wide Range ◽  
Neural Tissues ◽  
Synaptic Junctions ◽  
The Central Nervous System ◽  
Electron Microscopic Appearance

George Gray was an early contributor to our knowledge of the electron microscopic appearance of the central nervous system. He was skilful with the difficult techniques for preparing the tissues, worked rapidly, and was an astute observer. Sitting with him in the dark, staring at a dim image that George was moving rapidly as he searched for significant detail, could be an exciting experience. He had clear ideas about features that mattered and could quickly relate the two-dimensional electron microscopic images to the three-dimensional neural structures under investigation. He is best known for his detailed and perceptive description of synaptic junctions in the mammalian neocortex, and his name is still linked to two distinct junctional types (Gray's type 1 and Gray's type 2), now recognized as generally distinguishing excitatory from inhibitory junctions. He studied a wide range of neural tissues, played a significant role in the early isolation of ‘synaptosomes’, contributed greatly to the rapid advance of knowledge that accompanied the early application of the electron microscope to neural tissues, and influenced a great many later fine-structural studies of the nervous system.

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