Muscarinic presynaptic modulation in GABAergic pallidal synapses of the rat

2015 ◽  
Vol 113 (3) ◽  
pp. 796-807 ◽  
Author(s):  
Ricardo Hernández-Martínez ◽  
José J. Aceves ◽  
Pavel E. Rueda-Orozco ◽  
Teresa Hernández-Flores ◽  
Omar Hernández-González ◽  
...  
Keyword(s):  
Receptor Agonist ◽  
Projection Neurons ◽  
Quantal Content ◽  
Short Term ◽  
Paired Pulse ◽  
Short Term Plasticity ◽  
Striatal Projection Neurons ◽  
Muscarinic Cholinergic ◽  
Muscarinic Modulation

The external globus pallidus (GPe) is central for basal ganglia processing. It expresses muscarinic cholinergic receptors and receives cholinergic afferents from the pedunculopontine nuclei (PPN) and other regions. The role of these receptors and afferents is unknown. Muscarinic M1-type receptors are expressed by synapses from striatal projection neurons (SPNs). Because axons from SPNs project to the GPe, one hypothesis is that striatopallidal GABAergic terminals may be modulated by M1 receptors. Alternatively, some M1 receptors may be postsynaptic in some pallidal neurons. Evidence of muscarinic modulation in any of these elements would suggest that cholinergic afferents from the PPN, or other sources, could modulate the function of the GPe. In this study, we show this evidence using striatopallidal slice preparations: after field stimulation in the striatum, the cholinergic muscarinic receptor agonist muscarine significantly reduced the amplitude of inhibitory postsynaptic currents (IPSCs) from synapses that exhibited short-term synaptic facilitation. This inhibition was associated with significant increases in paired-pulse facilitation, and quantal content was proportional to IPSC amplitude. These actions were blocked by atropine, pirenzepine, and mamba toxin-7, suggesting that receptors involved were M1. In addition, we found that some pallidal neurons have functional postsynaptic M1 receptors. Moreover, some evoked IPSCs exhibited short-term depression and a different kind of modulation: they were indirectly modulated by muscarine via the activation of presynaptic cannabinoid CB1 receptors. Thus pallidal synapses presenting distinct forms of short-term plasticity were modulated differently.

Differences in synaptic integration between direct and indirect striatal projection neurons: Role of CaV 3 channels

Synapse ◽  
2018 ◽  
Vol 73 (4) ◽  
pp. e22079 ◽  
Author(s):  
Brisa García-Vilchis ◽  
Paola Suárez ◽  
Miguel Serrano-Reyes ◽  
Mario Arias-García ◽  
Dagoberto Tapia ◽  
...  
Keyword(s):  
Synaptic Integration ◽  
Projection Neurons ◽  
Striatal Projection Neurons

A Simple Depletion Model of the Readily Releasable Pool of Synaptic Vesicles Cannot Account for Paired-Pulse Depression

2007 ◽  
Vol 97 (1) ◽  
pp. 948-950 ◽  
Author(s):  
Jane M. Sullivan
Keyword(s):  
Synaptic Vesicles ◽  
Hippocampal Neurons ◽  
Synaptic Activity ◽  
Excitatory Synapses ◽  
Short Term ◽  
Paired Pulse ◽  
Short Term Plasticity ◽  
Releasable Pool ◽  
Readily Releasable Pool ◽  
Paired Pulse Depression

Paired-pulse depression (PPD) is a form of short-term plasticity that plays a central role in processing of synaptic activity and is manifest as a decrease in the size of the response to the second of two closely timed stimuli. Despite mounting evidence to the contrary, PPD is still commonly thought to reflect depletion of the pool of synaptic vesicles available for release in response to the second stimulus. Here it is shown that PPD cannot be accounted for by depletion at excitatory synapses made by hippocampal neurons because PPD is unaffected by changes in the fraction of the readily releasable pool (RRP) released by the first of a pair of pulses.

scholarly journals 1M0900 The role of Ca^ concentration for short term plasticity (augmentation, potentiation)

2002 ◽  
Vol 42 (supplement2) ◽  
pp. S73
Author(s):  
H. Yamamoto ◽  
M. Murase ◽  
N. Suzuki
Keyword(s):  
Short Term ◽  
Short Term Plasticity

Differential cortical activation of the striatal direct and indirect pathway cells: reconciling the anatomical and optogenetic results by using a computational method

2014 ◽  
Vol 112 (1) ◽  
pp. 120-146 ◽  
Author(s):  
Kenji Morita
Keyword(s):  
D2 Receptor ◽  
Computational Method ◽  
Cortical Activation ◽  
Projection Neurons ◽  
Indirect Pathway ◽  
Short Term ◽  
Apparent Contradiction ◽  
Striatal Projection Neurons ◽  
Cortical Inputs ◽  
Stimulation Of

The corticostriatal system is considered to be crucially involved in learning and action selection. Anatomical studies have shown that two types of corticostriatal neurons, intratelencephalic (IT) and pyramidal tract (PT) cells, preferentially project to dopamine D1 or D2 receptor-expressing striatal projection neurons, respectively. In contrast, an optogenetic study has shown that stimulation of IT axons evokes comparable responses in D1 and D2 cells and that stimulation of PT axons evokes larger responses in D1 cells. Since the optogenetic study applied brief stimulation only, however, the overall impacts of repetitive inputs remain unclear. Moreover, the apparent contradiction between the anatomical and optogenetic results remains to be resolved. I addressed these issues by using a computational approach. Specifically, I constructed a model of striatal response to cortical inputs, with parameters regarding short-term synaptic plasticity and anatomical connection strength for each connection type. Under the constraint of the optogenetic results, I then explored the parameters that best explain the previously reported paired-pulse ratio of response in D1 and D2 cells to cortical and intrastriatal stimulations, which presumably recruit different compositions of IT and PT fibers. The results indicate that 1) IT→D1 and PT→D2 connections are anatomically stronger than IT→D2 and PT→D1 connections, respectively, consistent with the previous findings, and that 2) IT→D1 and PT→D2 synapses entail short-term facilitation, whereas IT→D2 and PT→D1 synapses would basically show depression, and thereby 3) repetitive IT or PT inputs have larger overall impacts on D1 or D2 cells, respectively, supporting a recently proposed hypothesis on the roles of corticostriatal circuits in reinforcement learning.

scholarly journals Effects of short-term plasticity in early olfactory information processing in Drosophila

2021 ◽  
Author(s):  
Yuxuan Liu ◽  
Qianyi Li ◽  
Chao Tang ◽  
Shanshan Qin ◽  
Yuhai Tu
Keyword(s):  
Experimental Data ◽  
Adaptive Response ◽  
Neural Circuit ◽  
Dominant Factor ◽  
Projection Neurons ◽  
Short Term ◽  
Information Process ◽  
Short Term Plasticity ◽  
Olfactory Information ◽  
Divisive Normalization

In Drosophila, olfactory information received by the olfactory receptor neurons (ORNs) is first processed by an incoherent feed forward neural circuit in the antennal lobe (AL) that consists of ORNs (input), the inhibitory local neurons (LNs), and projection neurons (PNs). This "early" olfactory information process has two important characteristics. First, response of a PN to its cognate ORN is normalized by the overall activity of other ORNs, a phenomenon termed "divisive normalization". Second, PNs respond strongly to the onset of ORN activities, but they adapt to prolonged or continuously increasing inputs. Despite the importance of these characteristics for learning and memory, their underlying mechanism remains not fully understood. Here, we develop a circuit model for describing the ORN-LN-PN dynamics by including key features of neuron-neuron interactions, in particular short-term plasticity (STP) and presynaptic inhibition (PI).Our model shows that STP is critical in shaping PN's steady-state response properties. By fitting our model to experimental data quantitatively, we found that strong and balanced short-term facilitation (STF) and short-term depression (STD) in STP is crucial for the observed nonlinear divisive normalization in Drosophila. By comparing our model with the observed adaptive response to time-varying signals quantitatively, we find that both STP and PI contribute to the highly adaptive response with the latter being the dominant factor for a better fit with experimental data. Our model not only helps reveal the mechanisms underlying two main characteristics of the early olfactory process, it can also be used to predict the PN responses to arbitrary time-dependent signals and to infer microscopic properties of the circuit (such as the strengths of STF and STD) from the measured input-output relation.

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