scholarly journals A role for action-potential activity in the development of neuronal connections in the kitten retinogeniculate pathway

1986 ◽  
Vol 6 (4) ◽  
pp. 1021-1036 ◽  
Author(s):  
MW Dubin ◽  
LA Stark ◽  
SM Archer
2018 ◽  
Vol 24 (5) ◽  
pp. 471-485 ◽  
Author(s):  
Jillian Belgrad ◽  
R. Douglas Fields

The temporal coding of action potential activity is fundamental to nervous system function. Here we consider how gene expression in neurons is regulated by specific patterns of action potential firing, with an emphasis on new information on epigenetic regulation of gene expression. Patterned action potential activity activates intracellular signaling networks selectively in accordance with the kinetics of activation and inactivation of second messengers, phosphorylation and dephosphorylation of protein kinases, and cytoplasmic and nuclear calcium dynamics, which differentially activate specific transcription factors. Increasing evidence also implicates activity-dependent regulation of epigenetic mechanisms to alter chromatin architecture. Changes in three-dimensional chromatin structure, including chromatin compaction, looping, double-stranded DNA breaks, histone and DNA modification, are altered by action potential activity to selectively inhibit or promote transcription of specific genes. These mechanisms of activity-dependent regulation of gene expression are important in neural development, plasticity, and in neurological and psychological disorders.


1980 ◽  
Vol 43 (3) ◽  
pp. 669-685 ◽  
Author(s):  
R. Gillette ◽  
M. U. Gillette ◽  
W. J. Davis

1. The ventral white cells (VWC's) of the buccal ganglion of Pleurobranchaea, so named for their position and color, are a bilateral pair of neuron somata. Each sends a single axon out its contralateral stomatogastric nerve and has a dendritic field originating close to the soma. 2. The vwcs exhibit spontaneous episodes of prolonged depolarization (duration 1--4 min) accompanied by repetitive action-potential activity and separated by regular intervals of 3--30 min. Such prolonged burst episodes can be triggered by short pulses of depolarizing current. During the repetitive activity of the spontaneous bursts or that driven by imposed depolarization, the action potentials progressively broaden to 5--16 times their initial duration. 3. During spontaneous bursting or activity driven by imposed depolarization, the cyclic motor output of the feeding network is initiated or accelerated with a latency corresponding with the development of appreciable VWC spike broadening. When broadening of antidromic VWC spikes is suppressed by imposed hyperpolarization of the soma, the frequency of feeding cycles is significantly lower than when broadened spikes are allowed to develop. When trains of spikes are driven by depolarizing current, the motor output of the feeding network is not initiated until the VWC spikes have broadened to a repeatable "threshold" duration, regardless of the intensity of the depolarizing current. 4. The endogenous production of prolonged burst episodes, triggered by depolarizing current pulses, and progressive spike broadening can be demonstrated in the surgically isolated VWC soma. 5. The paired VWCs are strongly electrically coupled and display highly synchronous activity. They receive synaptic inputs from many previously identified interneurons of the feeding network and are thus reciprocally coupled within the network. 6. These results demonstrate that the capacity of this neuron to generate broadened action potentials during repetitive activity confers the ability to command coordinated motor-network output. The appropriate repetitive activity can be produced endogenously in the form of prolonged bursts of spikes.


2017 ◽  
Author(s):  
Brendon O. Watson ◽  
Mingxin Ding ◽  
György Buzsáki

AbstractThe local field potential (LFP) is an aggregate measure of group neuronal activity and is often correlated with the action potentials of single neurons. In recent years investigators have found that action potential firing rates increase during elevations in power high-frequency band oscillations (50-200 Hz range). However action potentials also contribute to the LFP signal itself, making the spike–LFP relationship complex. Here we examine the relationship between spike rates and LFPs in varying frequency bands in rat neocortical recordings. We find that 50-180Hz oscillations correlate most consistently with high firing rates, but that other LFPs bands also carry information relating to spiking, including in some cases anti-correlations. Relatedly, we find that spiking itself and electromyographic activity contribute to LFP power in these bands. The relationship between spike rates and LFP power varies between brain states and between individual cells. Finally, we create an improved oscillation-based predictor of action potential activity by specifically utilizing information from across the entire recorded frequency spectrum of LFP. The findings illustrate both caveats and improvements to be taken into account in attempts to infer spiking activity from LFP.


1994 ◽  
Vol 72 (6) ◽  
pp. 2853-2863 ◽  
Author(s):  
C. J. McBain

1. Whole cell patch-clamp recordings were made from CA1 stratum oriens inhibitory neurons of rat hippocampal slices in vitro to determine their contribution to the epileptiform activity elicited by elevating the extracellular potassium ion concentration ([K+]o) from 3.5 to 8.5 mm. 2. Under current-clamp conditions, spontaneous action potential activity in inhibitory neurons normally occurs in a sustained repetitive firing mode paced by nonsynaptic, intrinsic mechanisms. On elevation of [K+]o to 8.5 mm the pattern of activity is altered such that clusters of action potentials occur interrupted by periods of silence without an appreciable afterhyperpolarization (AHP). In addition, elevation of [K+]o caused a large reduction in the action potential AHP amplitude and duration concomitant with a 20-mV shift in the reversal potential of the AHP. 3. In voltage clamp a small persistent inward current was observed after the introduction of elevated potassium concomitant with an increase in the frequency of spontaneous excitatory post-synaptic currents (EPSCs) in all interneurons studied. After a short period of time (approximately 1 min) temporal summation of synchronously occurring EPSCs contributed a periodic inward current (PIC; 10-40 pA, 0.8 Hz) that persisted for the duration of the [K+]o elevation. Analysis of the charge transfer associated with the PIC suggests that they comprise the temporal summation of approximately 35 EPSCs. This PIC was synchronous with the extracellular field potential recorded from the CA1 pyramidal neuron layer. 4. The PIC was responsible for the clustering of action potential activity because blockade of EPSC activity by the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist 6,7-dinitroquinoxaline-2,3-dione (DNQX) abolished PICs and reverted action potential activity to single sustained firing, despite the continued application of 8.5 mm [K+]o. Antagonists of N-methyl-D-aspartate receptors were without effect on either the PICs or the action potential activity. 5. Addition of the metabotropic glutamate receptor (mGluR) antagonist (+)-2-methyl-4-carboxyphenylglycine (MCPG) reversibly abolished the PIC without affecting the increase in EPSC frequency. 6. Recordings from CA3 pyramidal neurons in 8.5 mm [K+]o demonstrated that interictal activity occurred at a frequency identical to the PICs observed in interneurons. Interictal activity in CA3 pyramidal neurons was attenuated but never abolished by MCPG, suggesting a role for mGluR receptors in the maintenance of interictal activity in area CA3.(ABSTRACT TRUNCATED AT 400 WORDS)


2020 ◽  
Vol 118 (3) ◽  
pp. 457a
Author(s):  
Michael G. Jonz ◽  
Michael W. Country ◽  
Katrin Blank ◽  
Jeffrey C. Smith

1980 ◽  
Vol 87 (1) ◽  
pp. 285-313
Author(s):  
J. A. Benson

1. The five large and four small neurones in the cardiac ganglion of the crab, Portunus, are electrotonically coupled and behave as a single relaxation oscillator, exhibiting periodic bursting activity in vitro. Recorded from the large neurone somata, this activity consists of 200-400 ms slow depolarizations called ‘driver potentials’ (Tazaki & Cooke, 1979a), accompanied by attenuated action potentials and EPSP's from small neurone input. 2. There is a strong positive correlation between the duration of the driver potential and the duration of the following interburst interval in the spontaneously active ganglion. This correlation is preserved during prolonged depolarization and hyperpolarization. 3. When a driver potential is prematurely terminated by an injected current pulse, the following interburst interval is shortened in direct proportion to the decrease in driver potential duration. 4. When a driver potential or a burst of high-frequency action potential activity is evoked by a depolarizing current pulse, the cardiac oscillator resets to the point of maximum hyperpolarization of the burst cycle, and the following interburst interval is of normal duration. Resetting following an evoked driver potential is complete. Partial resetting occurs only after short, evoked action potential bursts in the absence of a driver potential. 5. Reset of the oscillator causes phase shifts in the subsequent cycles of activity, which vary with the phase of application and duration of the injected current pulse. Response curves have been constructed for a comprehensive range of durations and intensities of hyperpolarizing and depolarizing current pulses applied at all phases of the oscillator cycle. 6. The phase shifts are composed of contributions from the duration of the current pulse, from the premature initiation of the slow depolarizing pacemaker potential due to early termination of the burst, and from the change in interburst interval correlated with truncation of the driver potential. 7. Considering the cardiac ganglion as a relaxation oscillator, frequencey control by entrainment to periodically applied current pulses was quantitatively predicted from the phase-response curves and experimentally confirmed. 8. A high concentration (10(−5) M) of octopamine can inhibit driver potential activity in the large neurones. This was used to examine possible frequency modulating effects of electrotonic feedback from the large neurone driver potentials onto the small neurone pacemaker activity. 9. The observations are discussed in relation to the ionic model for driver potentials and slow pacemaker potential activity in the cardiac ganglion, as proposed by Tazaki & Cooke (1979a, b).


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