scholarly journals Release probability increases towards distal dendrites boosting high-frequency signal transfer

2020 ◽  
Author(s):  
Thomas P. Jensen ◽  
Olga Kopach ◽  
Leonid P. Savchenko ◽  
James P. Reynolds ◽  
Dmitri A. Rusakov
Keyword(s):  
High Frequency ◽  
Memory Trace ◽  
Hippocampal Slices ◽  
Network Activity ◽  
Signal Transfer ◽  
High Frequency Signal ◽  
Release Probability ◽  
Synaptic Receptor ◽  
Acute Hippocampal Slices ◽  
Trace Formation

ABSTRACTDendritic integration of synaptic inputs entangles their increased electrotonic attenuation at distal dendrites, which can be counterbalanced by the increased synaptic receptor density. However, during sustained network activity the influence of individual synapses depends on their release properties. How these properties are distributed along dendrites remains poorly understood. Here, we employed classical optical quantal analyses and a genetically encoded optical glutamate sensor in acute hippocampal slices to monitor release at CA3-CA1 synapses. We find that their release probability increases with greater distances from the soma. Similar-fidelity synapses tend to group together whereas release probability shows no trends regarding the within-branch position. Simulations with a realistic CA1 pyramidal cell hosting stochastic synapses suggest that the observed trends boost signal transfer fidelity, particularly at higher input frequencies. Because high-frequency bursting has been associated with learning, the release probability pattern we have found may play a key role in memory trace formation.

scholarly journals Release probability increases towards distal dendrites boosting high-frequency signal transfer in the rodent hippocampus

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Thomas P Jensen ◽  
Olga Kopach ◽  
James P Reynolds ◽  
Leonid P Savtchenko ◽  
Dmitri A Rusakov
Keyword(s):  
High Frequency ◽  
Glutamate Release ◽  
Hippocampal Slices ◽  
Network Activity ◽  
Signal Transfer ◽  
High Frequency Signal ◽  
Release Probability ◽  
Acute Hippocampal Slices ◽  
Rats And Mice ◽  
Trace Formation

Dendritic integration of synaptic inputs involves their increased electrotonic attenuation at distal dendrites, which can be counterbalanced by the increased synaptic receptor density. However, during network activity, the influence of individual synapses depends on their release fidelity, the dendritic distribution of which remains poorly understood. Here, we employed classical optical quantal analyses and a genetically encoded optical glutamate sensor in acute hippocampal slices of rats and mice to monitor glutamate release at CA3-CA1 synapses. We find that their release probability increases with greater distances from the soma. Similar-fidelity synapses tend to group together, whereas release probability shows no trends regarding the branch ends. Simulations with a realistic CA1 pyramidal cell hosting stochastic synapses suggest that the observed trends boost signal transfer fidelity, particularly at higher input frequencies. Because high-frequency bursting has been associated with learning, the release probability pattern we have found may play a key role in memory trace formation.

Copper Plating Method on Flat Surface for High Frequency Signal Transfer

2005 ◽  
Vol 44 (9A) ◽  
pp. 6719-6725 ◽  
Author(s):  
Koichi Hontake ◽  
Yasuhiro Wakizaka ◽  
Akihiko Furuya ◽  
Daisuke Uchida ◽  
Koichiro Kuribayashi ◽  
...  
Keyword(s):  
High Frequency ◽  
Flat Surface ◽  
Copper Plating ◽  
Signal Transfer ◽  
Frequency Signal ◽  
High Frequency Signal ◽  
Plating Method

Dither in a rolling airframe flight vehicle with a two-position actuator: An amplitude distribution approach

2016 ◽  
Vol 39 (8) ◽  
pp. 1205-1215 ◽  
Author(s):  
Bahram Mohammadi ◽  
Mohammad Reza Arvan ◽  
Yousof Koohmaskan
Keyword(s):  
High Frequency ◽  
Degrees Of Freedom ◽  
Coupling Effect ◽  
Cross Coupling ◽  
Amplitude Distribution ◽  
Feedback System ◽  
Flight Vehicle ◽  
Frequency Signal ◽  
High Frequency Signal ◽  
Minimal Error

Rolling airframe manoeuvring is a type of manoeuvre in which the missile provides continuous roll during flight. Cross-coupling between the angle of attack and sideslip in rolling airframe missiles (RAMs) yields a coning motion around the flight path. As the pitch and yaw cross-coupling effect decreases, the radius of this coning motion decreases and the accuracy of the control system increases. Two-position (on–off) actuators are used in most RAMs. The presence of a two-position actuator in a feedback system makes its characteristics non-linear. A high-frequency signal so-called dither is applied to compensate for the non-linearity effect of the actuator characteristic in the feedback system and to stabilize the coning motion. The amplitude distribution function (ADF) method in dither analysis shows that the smoothed non-linearity characteristic can be computed as the convolution of the original non-linearity and the ADF of the dither signal. According to the four-degrees-of-freedom (4-DOF) equations of RAMs in a non-rolling frame and regarding various dither signals through the ADF approach on a two-position actuator, an analytical condition for dither amplitude in coning motion stability of RAMs is derived. It was shown that the triangular signal with specified amplitude and high enough frequency led to a smoother response of two-position actuators. Finally, by applying beam-riding guidance to a RAM, the performance of dithers for decreasing the distance of the missile from the centre of the beam is validated through simulations. It is illustrated that applying the triangular dither resulted in minimal error.

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