Modulation of intracortical synaptic potentials by presynaptic somatic membrane potential

Nature ◽  
2006 ◽  
Vol 441 (7094) ◽  
pp. 761-765 ◽  
Author(s):  
Yousheng Shu ◽  
Andrea Hasenstaub ◽  
Alvaro Duque ◽  
Yuguo Yu ◽  
David A. McCormick
Keyword(s):  
Membrane Potential ◽  
Somatic Membrane ◽  
Synaptic Potentials

Subthreshold oscillations of the membrane potential: a functional synchronizing and timing device

1993 ◽  
Vol 70 (5) ◽  
pp. 2181-2186 ◽  
Author(s):  
I. Lampl ◽  
Y. Yarom
Keyword(s):  
Membrane Potential ◽  
Logic Gate ◽  
Maximum Amplitude ◽  
Sine Wave ◽  
Inferior Olivary Nucleus ◽  
Synaptic Potential ◽  
Synaptic Potentials ◽  
Subthreshold Oscillations ◽  
Inferior Olivary ◽  
Olivary Nucleus

1. Subthreshold membrane potential oscillations have been observed in different types of CNS neurons. In this in vitro study, we examined the possible role of these oscillations by analyzing the responses of neurons from the inferior olivary nucleus to a combined stimulation of sine wave and synaptic potentials. 2. A nonlinear summation of the sine wave and the synaptic potential occurred in olivary neurons; a superlinear summation occurred when the synaptic potential was elicited at the trough of the sine wave or during the rising phase. On the other hand, a less than linear summation occurred when the synaptic potentials were evoked during the falling phase of the wave. 3. Significant changes in the delay of the synaptic responses were observed. As a result of these changes, the maximum amplitude of the response occurred at the peak of the sine wave, regardless of the exact time of stimulation. The output of the neuron was therefore synchronized with the sine wave and depended only partly on the input phase. 4. These data demonstrate that neurons from the inferior olivary nucleus are capable of operating as accurate synchronizing devices. Moreover, by affecting the delay line, they act as a logic gate that ensures that the information will be added to the system only at given times.

Sustained membrane potential change of uropod motor neurons during the fictive abdominal posture movement in crayfish

1986 ◽  
Vol 56 (3) ◽  
pp. 702-717 ◽  
Author(s):  
M. Takahata ◽  
M. Hisada
Keyword(s):  
Membrane Potential ◽  
Motor Neurons ◽  
Membrane Resistance ◽  
Potential Change ◽  
Quiescent State ◽  
Membrane Potential Change ◽  
Synaptic Potentials ◽  
Nonspiking Interneurons ◽  
Body Rolling ◽  
Dendritic Branches

The occurrence of the uropod steering response as one of the equilibrium reflexes to body rolling in crayfish is significantly facilitated if the stimulus is given while the animal is performing the abdominal posture movement. This facilitation of the descending statocyst pathway by the abdominal posture system takes place between the uropod motor neurons and the statocyst interneurons, which directly project from the brain to the terminal abdominal ganglion where the motor neurons originate. To elucidate the synaptic mechanisms underlying the postural facilitation of the steering response, we analyzed in this study the activity of an identified set of uropod motor neurons during the fictive abdominal extension movement in the whole-animal preparation. Intracellular recordings from the dendritic branches of uropod motor neurons revealed that they were continuously excited during the fictive abdominal extension. The large fast motor neurons usually showed a sustained depolarization of the subthreshold magnitude. The small slow ones showed a suprathreshold sustained depolarization with spikes superimposed. Putative inhibitory motor neurons, on the other hand, showed a sustained hyperpolarization with their spontaneous spike discharge suppressed. The discrete synaptic potentials could hardly be distinguished and, instead, small fluctuations of the membrane potential were observed during the sustained depolarization of both the fast and slow motor neurons. Occasionally, large discrete synaptic potentials could be observed to be superimposed on the sustained depolarization. The occurring frequency of these synaptic potentials showed, however, no significant increase associated with the sustained depolarization. It hence seemed unlikely that these potentials were responsible for producing the sustained depolarization. Their amplitude during the sustained depolarization was smaller than that observed during the quiescent state. The sustained membrane potential change during the fictive abdominal movement was also observed in many neurons other than motor neurons, including local nonspiking interneurons and mechanosensory spiking interneurons. Both motor neurons and interneurons showed a decrease in their membrane resistance during the sustained membrane potential change. We concluded that the sustained depolarization of uropod motor neurons during the fictive abdominal extension was produced by the summation of small chemically transmitted postsynaptic potentials.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Somatic Membrane Potential and Kv1 Channels Control Spike Repolarization in Cortical Axon Collaterals and Presynaptic Boutons

2011 ◽  
Vol 31 (43) ◽  
pp. 15490-15498 ◽  
Author(s):  
A. J. Foust ◽  
Y. Yu ◽  
M. Popovic ◽  
D. Zecevic ◽  
D. A. McCormick
Keyword(s):  
Membrane Potential ◽  
Somatic Membrane ◽  
Axon Collaterals ◽  
Presynaptic Boutons

Differential localization of 5-HT1 receptors on myenteric and submucosal neurons

1988 ◽  
Vol 255 (5) ◽  
pp. G603-G611 ◽  
Author(s):  
J. J. Galligan ◽  
A. Surprenant ◽  
M. Tonini ◽  
R. A. North
Keyword(s):  
Membrane Potential ◽  
Guinea Pig ◽  
Myenteric Plexus ◽  
Potassium Conductance ◽  
Enteric Neurons ◽  
Nerve Terminals ◽  
Intracellular Recordings ◽  
Myenteric Neurons ◽  
Synaptic Potentials ◽  
Selective Agonists

Intracellular recordings were made from guinea pig enteric neurons, and the effects of 5-hydroxytryptamine (5-HT) and the 5-HT1 selective agonists 5-carboxyamidotryptamine (5-CT) and 8-hydroxy-2-(n-dipropylamino)tetralin (DPAT) were studied on membrane potential and synaptic potentials. Most myenteric AH neurons were hyperpolarized when these agonists were applied by superfusion; this hyperpolarization was due to an increase in potassium conductance. Membrane hyperpolarizations to 5-HT, 5-CT, or DPAT were never observed in submucous neurons. Fast nicotinic excitatory postsynaptic potentials (EPSPs) and slow EPSPs recorded from S neurons in the myenteric plexus were suppressed by 5-HT, 5-CT, and DPAT; slow EPSPs in myenteric AH neurons were also inhibited by these agonists. Fast and slow EPSPs recorded from submucous S neurons were not affected by 5-CT or DPAT. However, slow EPSPs recorded from submucous AH neurons were readily blocked by 5-CT and DPAT. The results indicate that 5-HT1 receptors are located on the cell bodies of myenteric but not submucosal neurons. The nerve terminals that release the mediator or mediators of fast and slow synaptic potentials in myenteric neurons also have 5-HT1 receptors and presumably arise from other myenteric neurons; the nerve terminals responsible for the slow EPSP to AH neurons seem to be the only elements of the submucous plexus that express 5-HT1 receptors.

scholarly journals Control of somatic membrane potential in nociceptive neurons and its implications for peripheral nociceptive transmission

Pain ◽  
2014 ◽  
Vol 155 (11) ◽  
pp. 2306-2322 ◽  
Author(s):  
Xiaona Du ◽  
Han Hao ◽  
Sylvain Gigout ◽  
Dongyang Huang ◽  
Yuehui Yang ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Somatic Membrane ◽  
Nociceptive Neurons ◽  
Nociceptive Transmission

scholarly journals Impact of subthreshold membrane potential on synaptic responses at dendritic spines of layer 5 pyramidal neurons in the prefrontal cortex

2014 ◽  
Vol 111 (10) ◽  
pp. 1960-1972 ◽  
Author(s):  
Hannah J. Seong ◽  
Rudy Behnia ◽  
Adam G. Carter
Keyword(s):  
Prefrontal Cortex ◽  
Membrane Potential ◽  
Nmda Receptors ◽  
Dendritic Spines ◽  
Pyramidal Neurons ◽  
K Channels ◽  
Two Photon ◽  
Synaptic Potentials ◽  
Ampa And Nmda Receptors ◽  
Synaptic Responses

Glutamatergic inputs onto cortical pyramidal neurons are received and initially processed at dendritic spines. AMPA and NMDA receptors generate both synaptic potentials and calcium (Ca) signals in the spine head. These responses can in turn activate a variety of Ca, sodium (Na), and potassium (K) channels at spines. In principle, the roles of these receptors and channels can be strongly regulated by the subthreshold membrane potential. However, the impact of different receptors and channels has usually been studied at the level of dendrites. Much less is known about their influence at spines, where synaptic transmission and plasticity primarily occur. Here we examine single-spine responses in the basal dendrites of layer 5 pyramidal neurons in the mouse prefrontal cortex. Using two-photon microscopy and two-photon uncaging, we first show that synaptic potentials and Ca signals differ at resting and near-threshold potentials. We then determine how subthreshold depolarizations alter the contributions of AMPA and NMDA receptors to synaptic responses. We show that voltage-sensitive Ca channels enhance synaptic Ca signals but fail to engage small-conductance Ca-activated K (SK) channels, which require greater numbers of inputs. Finally, we establish how the subthreshold membrane potential controls the ability of voltage-sensitive Na channels and K channels to influence synaptic responses. Our findings reveal how subthreshold depolarizations promote electrical and biochemical signaling at dendritic spines by regulating the contributions of multiple glutamate receptors and ion channels.

scholarly journals Two Distinct Mechanisms Mediate Potentiating Effects of Depolarization on Synaptic Transmission

2009 ◽  
Vol 102 (3) ◽  
pp. 1976-1983 ◽  
Author(s):  
Bjoern Ch. Ludwar ◽  
Colin G. Evans ◽  
Jian Jing ◽  
Elizabeth C. Cropper
Keyword(s):  
Membrane Potential ◽  
Synaptic Transmission ◽  
Synaptic Input ◽  
Calcium Concentration ◽  
Rhythmic Activity ◽  
Dependent Manner ◽  
Output Process ◽  
Somatic Membrane ◽  
Different Types ◽  
Differential Control

Two distinct mechanisms mediate potentiating effects of depolarization on synaptic transmission. Recently there has been renewed interest in a type of plasticity in which a neuron's somatic membrane potential influences synaptic transmission. We study mechanisms that mediate this type of control at a synapse between a mechanoafferent, B21, and B8, a motor neuron that receives chemical synaptic input. Previously we demonstrated that the somatic membrane potential determines spike propagation within B21. Namely, B21 must be centrally depolarized if spikes are to propagate to an output process. We now demonstrate that this will occur with central depolarizations that are only a few millivolts. Depolarizations of this magnitude are not, however, sufficient to induce synaptic transmission to B8. B21-induced postsynaptic potentials (PSPs) are only observed if B21 is centrally depolarized by ≥10 mV. Larger depolarizations have a second impact on B21. They induce graded changes in the baseline intracellular calcium concentration that are virtually essential for the induction of chemical synaptic transmission. During motor programs, subthreshold depolarizations that increase calcium concentrations are observed during one of the two antagonistic phases of rhythmic activity. Chemical synaptic transmission from B21 to B8 is, therefore, likely to occur in a phase-dependent manner. Other neurons that receive mechanoafferent input are electrically coupled to B21. Differential control of spike propagation and chemical synaptic transmission may, therefore, represent a mechanism that permits selective control of afferent transmission to different types of neurons contacted by B21. Afferent transmission to neurons receiving chemical synaptic input will be phase specific, whereas transmission to electrically coupled followers will be phase independent.

Isolated NMDA receptor-mediated synaptic responses express both LTP and LTD

1992 ◽  
Vol 67 (4) ◽  
pp. 1009-1013 ◽  
Author(s):  
X. Xie ◽  
T. W. Berger ◽  
G. Barrionuevo
Keyword(s):  
Membrane Potential ◽  
Nmda Receptor ◽  
Cell Membrane ◽  
Synaptic Transmission ◽  
Granule Cell ◽  
Long Term Potentiation ◽  
Cell Membrane Potential ◽  
Synaptic Potentials ◽  
Synaptic Responses

1. The possibility of use-dependent, long-lasting modifications of pharmacologically isolated N-methyl-D-aspartate (NMDA) receptor-mediated synaptic transmission was examined by intracellular recordings from granule cells of the hippocampal dentate gyrus in vitro. In the presence of the non-NMDA receptor antagonist 6-cyano-7-nitroquinaxaline-2,3-dione (CNQX, 10 microM) robust, long-term potentiation (LTP) of NMDA receptor-mediated synaptic potentials was induced by brief, high (50 Hz) and lower (10 Hz) frequency tetanic stimuli of glutamatergic afferents (60 +/- 6%, n = 8, P less than 0.001 and 43 +/- 12%, n = 3, P less than 0.05, respectively). 2. Hyperpolarization of granule cell membrane potential to -100 mV during 50-Hz tetanic stimuli reversibly blocked the induction of LTP (-6 +/- 2%, n = 6, P greater than 0.05) indicating that simultaneous activation of pre- and postsynaptic elements is a prerequisite for potentiation of NMDA receptor-mediated synaptic transmission. In contrast, hyperpolarization of the granule cell membrane potential to -100 mV during 10-Hz tetanic stimuli resulted in long-term depression (LTD) of NMDA receptor-mediated synaptic potentials (-34 +/- 8%, n = 8, P less than 0.01). 3. We also studied the role of [Ca2+]i in the induction of LTP and LTD of NMDA receptor-mediated synaptic responses. Before tetanization, [Ca2+]i was buffered by iontophoretic injections of bis-(o-aminophenoxy)-N,N,N',N'-tetraacetic acid (BAPTA). BAPTA completely blocked the induction of LTP (3 +/- 5%, n = 13) and partially blocked LTD (-14.8 +/- 6%, n = 10).(ABSTRACT TRUNCATED AT 250 WORDS)

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