Emergence of Action Potential Generation and Synaptic Transmission in Vestibular Nucleus Neurons

2006 ◽  
Vol 96 (3) ◽  
pp. 1215-1226 ◽  
Author(s):  
Mei Shao ◽  
June C. Hirsch ◽  
Kenna D. Peusner
Keyword(s):  
Nerve Stimulation ◽  
Vestibular Nucleus ◽  
Vestibular Nerve ◽  
Action Potential Generation ◽  
Potential Generation ◽  
Low Frequencies ◽  
Excitatory Postsynaptic Currents ◽  
Principal Cells ◽  
Functional Development

Principal cells of the chick tangential nucleus are vestibular nucleus neurons in the hindbrain. Although detailed information is available on the morphogenesis of principal cells and synaptogenesis of primary vestibular fibers, this is the first study of their early functional development, when vestibular terminals emerge at embryonic days 10 and 13 (E10 and E13). At E10, 60% of principal cells generated spikes on depolarization, whereas 50% exhibited excitatory postsynaptic currents (EPSCs) on vestibular-nerve stimulation. The frequency was 0.2 Hz for glutamatergic spontaneous EPSCs (sEPSCs) at −60 mV, and 0.6 Hz for spontaneous inhibitory postsynaptic current (sIPSC) at +10 mV and completely GABAergic. All of these synaptic events were TTX-insensitive, miniature events. At E13, 50% of principal cells generated spikes on depolarization and 82% exhibited EPSCs on vestibular-nerve stimulation. The frequency was 0.7 Hz for sEPSCs at −60 mV, and 0.8 Hz for sIPSCs at +10 mV. Most principal cells had sIPSCs composed of both GABAergic (75%) and glycinergic (25%) events, but a few cells had only GABAergic sIPSCs. TTX decreased the frequency of EPSCs by 12%, and the IPSCs by 17%. In summary, at E10, some principal cells generated immature spikes on depolarization and EPSCs on vestibular-nerve stimulation. At E10, GABAergic events predominated, AMPA events had low frequencies, and glycinergic activity was absent. By E13, glycinergic events first appeared. This data were compared systematically to that obtained from the late-term embryo and hatchling to reveal the long-term sequence of changes in synaptic events and excitability and offer a broader understanding of how the vestibular system is assembled during development.

scholarly journals A multi-scale model reveals cellular and physiological mechanisms underlying hyperpolarisation-gated synaptic plasticity

2018 ◽  
Author(s):  
Yubin Xie ◽  
Marcel Kazmierczyk ◽  
Bruce P. Graham ◽  
Mayank B. Dutia ◽  
Melanie I. Stefan ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Nerve Stimulation ◽  
Vestibular Nerve ◽  
Biochemical Reaction ◽  
Medial Vestibular Nucleus ◽  
Scale Model ◽  
Reaction Systems ◽  
Multi Scale ◽  
Wide Range

AbstractNeurons in the medial vestibular nucleus (MVN) display hyperpolarisation-gated synaptic plasticity, where inhibition believed to come from cerebellar cortical Purkinje cells can induce long-term potentiation (LTP) or long-term depression (LTD) of vestibular nerve afferent synapses. This phenomenon is thought to underlie the plasticity of the vestibulo-ocular reflex (VOR). The molecular and cellular mechanisms involved are largely unknown. Here we present a novel multi-scale computational model, which captures both electrophysiological and biochemical signalling at vestibular nerve synapses on proximal dendrites of the MVN neuron. We show that AMPA receptor phosphorylation at the vestibular synapse depends in complex ways on dendritic calcium influx, which is in turn shaped by patterns of post-synaptic hyperpolarisation and vestibular nerve stimulation. Hyperpolarisation-gated synaptic plasticity critically depends on the activation of LVA calcium channels and on the interplay between CaMKII and PP2B in dendrites of the post-synaptic MVN cell. The extent and direction of synaptic plasticity depend on the strength and duration of hyperpolarisation, and on the relative timing of hyperpolarisation and vestibular nerve stimulation. The multi-scale model thus enables us to explore in detail the interactions between electrophysiological activation and post-synaptic biochemical reaction systems. More generally, this model has the potential to address a wide range of questions about neural signal integration, post-synaptic biochemical reaction systems and plasticity.

scholarly journals Activity-dependent mismatch between axo-axonic synapses and the axon initial segment controls neuronal output

2015 ◽  
Vol 112 (31) ◽  
pp. 9757-9762 ◽  
Author(s):  
Winnie Wefelmeyer ◽  
Daniel Cattaert ◽  
Juan Burrone
Keyword(s):  
Action Potential ◽  
Hippocampal Neurons ◽  
Initial Segment ◽  
Pyramidal Neurons ◽  
Neuronal Cell ◽  
Axon Initial Segment ◽  
Action Potential Generation ◽  
Potential Generation ◽  
Auditory Nucleus

The axon initial segment (AIS) is a structure at the start of the axon with a high density of sodium and potassium channels that defines the site of action potential generation. It has recently been shown that this structure is plastic and can change its position along the axon, as well as its length, in a homeostatic manner. Chronic activity-deprivation paradigms in a chick auditory nucleus lead to a lengthening of the AIS and an increase in neuronal excitability. On the other hand, a long-term increase in activity in dissociated rat hippocampal neurons results in an outward movement of the AIS and a decrease in the cell’s excitability. Here, we investigated whether the AIS is capable of undergoing structural plasticity in rat hippocampal organotypic slices, which retain the diversity of neuronal cell types present at postnatal ages, including chandelier cells. These interneurons exclusively target the AIS of pyramidal neurons and form rows of presynaptic boutons along them. Stimulating individual CA1 pyramidal neurons that express channelrhodopsin-2 for 48 h leads to an outward shift of the AIS. Intriguingly, both the pre- and postsynaptic components of the axo-axonic synapses did not change position after AIS relocation. We used computational modeling to explore the functional consequences of this partial mismatch and found that it allows the GABAergic synapses to strongly oppose action potential generation, and thus downregulate pyramidal cell excitability. We propose that this spatial arrangement is the optimal configuration for a homeostatic response to long-term stimulation.

Electrophysiologic Evidence for Involvement of Acetylcholine as a Neurotransmitter in the Lateral Vestibular Nucleus

1981 ◽  
Vol 89 (6) ◽  
pp. 1025-1029 ◽  
Author(s):  
Juichi Ito ◽  
Izuru Matsuoka ◽  
Masashi Sasa ◽  
Sakae Fujimoto ◽  
Shuji Takaori
Keyword(s):  
Nerve Stimulation ◽  
Vestibular Nucleus ◽  
Vestibular Nerve ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Spontaneous Firing ◽  
Lateral Vestibular Nucleus ◽  
Spike Generation

Monosynaptic spike generation of lateral vestibular nucleus (LVN) neurons with vestibular nerve stimulation in cats was inhibited by microiontophoretic atropine and gamma-aminobutyric acid (GABA). Spontaneous firing of the LVN monosynaptic neuron was increased by iontophoretic acetylcholine and glutamate. Atropine inhibited acetylcholine-induced firing without affecting glutamate-induced firing, while GABA blocked spike generation produced by acetylcholine and glutamate. Acetylcholine probably plays a role in transmission from the vestibular nerve to the LVN monosynaptic neurons.

Floccular Modulation of Vestibuloocular Pathways and Cerebellum-Related Plasticity: An In Vitro Whole Brain Study

2000 ◽  
Vol 84 (5) ◽  
pp. 2514-2528 ◽  
Author(s):  
Alexander L. Babalian ◽  
Pierre-Paul Vidal
Keyword(s):  
Purkinje Cells ◽  
Nerve Stimulation ◽  
Inferior Olive ◽  
Vestibular Nuclei ◽  
Vestibular Nerve ◽  
Abducens Nucleus ◽  
Postsynaptic Potentials ◽  
Oculomotor Nerves ◽  
Stimulation Of

The isolated whole brain (IWB) preparation of the guinea pig was used to investigate the floccular modulation of vestibular-evoked responses in abducens and oculomotor nerves and abducens nucleus; for identification of flocculus target neurons (FTNs) in the vestibular nuclei and intracellular study of some of their physiological properties; to search for possible flocculus-dependent plasticity at the FTN level by pairing of vestibular nerve and floccular stimulations; and to study the possibility of induction of long-term depression (LTD) in Purkinje cells by paired stimulation of the inferior olive and vestibular nerve. Stimulation of the flocculus had only effects on responses evoked from the ipsilateral (with respect to the stimulated flocculus) vestibular nerve. Floccular stimulation significantly inhibited the vestibular-evoked discharges in oculomotor nerves on both sides and the inhibitory field potential in the ipsilateral abducens nucleus while the excitatory responses in the contralateral abducens nerve and nucleus were free from such inhibition. Eleven second-order vestibular neurons were found to receive a short-latency monosynaptic inhibitory input from the flocculus and were thus characterized as FTNs. Monosynaptic inhibitory postsynaptic potentials from the flocculus were bicuculline sensitive, suggesting a GABAA-ergic transmission from Purkinje cells to FTNs. Two of recorded FTNs could be identified as vestibulospinal neurons by their antidromic activation from the cervical segments of the spinal cord. Several pairing paradigms were investigated in which stimulation of the flocculus could precede, coincide with, or follow the vestibular nerve stimulation. None of them led to long-term modification of responses in the abducens nucleus or oculomotor nerve evoked by activation of vestibular afferents. On the other hand, pairing of the inferior olive and vestibular nerve stimulation resulted in approximately a 30% reduction of excitatory postsynaptic potentials evoked in Purkinje cells by the vestibular nerve stimulation. This reduction was pairing-specific and lasted throughout the entire recording time of the neurons. Thus in the IWB preparation, we were able to induce a LTD in Purkinje cells, but we failed to detect traces of flocculus-dependent plasticity at the level of FTNs in vestibular nuclei. Although these data cannot rule out the possibility of synaptic modifications in FTNs and/or at other brain stem sites under different experimental conditions, they are in favor of the hypothesis that the LTD in the flocculus could be the essential mechanism of cellular plasticity in the vestibuloocular pathways.

Long Term Effects of Low Frequency (10 Hz) Vagus Nerve Stimulation on EEG and Heart Rate Variability in Crohn's Disease: A Case Report

2014 ◽  
Vol 7 (6) ◽  
pp. 914-916 ◽  
Author(s):  
Didier Clarençon ◽  
Sonia Pellissier ◽  
Valérie Sinniger ◽  
Astrid Kibleur ◽  
Dominique Hoffman ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Crohn’S Disease ◽  
Case Report ◽  
Vagus Nerve ◽  
Nerve Stimulation ◽  
Vagus Nerve Stimulation ◽  
Low Frequency ◽  
Long Term Effects

scholarly journals Responses of Vertebrate Wildlife to Oil and Natural Gas Development: Patterns and Frontiers

2021 ◽  
Author(s):  
A. D. Chalfoun
Keyword(s):  
Natural Gas ◽  
Anthropogenic Activities ◽  
Spatial Scales ◽  
Habitat Type ◽  
Population Level ◽  
Low Frequencies ◽  
Natural Gas Development ◽  
The Usa ◽  
Oil And Natural Gas

Abstract Purpose of Review Anthropogenic activities can lead to the loss, fragmentation, and alteration of wildlife habitats. I reviewed the recent literature (2014–2019) focused on the responses of avian, mammalian, and herpetofaunal species to oil and natural gas development, a widespread and still-expanding land use worldwide. My primary goals were to identify any generalities in species’ responses to development and summarize remaining gaps in knowledge. To do so, I evaluated the directionality of a wide variety of responses in relation to taxon, location, development type, development metric, habitat type, and spatiotemporal aspects. Recent Findings Studies (n = 70) were restricted to the USA and Canada, and taxonomically biased towards birds and mammals. Longer studies, but not those incorporating multiple spatial scales, were more likely to detect significant responses. Negative responses of all types were present in relatively low frequencies across all taxa, locations, development types, and development metrics but were context-dependent. The directionality of responses by the same species often varied across studies or development metrics. Summary The state of knowledge about wildlife responses to oil and natural gas development has developed considerably, though many biases and gaps remain. Studies outside of North America and that focus on herpetofauna are lacking. Tests of mechanistic hypotheses for effects, long-term studies, assessment of response thresholds, and experimental designs that isolate the effects of different stimuli associated with development, remain critical. Moreover, tests of the efficacy of habitat mitigation efforts have been rare. Finally, investigations of the demographic effects of development across the full annual cycle were absent for non-game species and are critical for the estimation of population-level effects.

scholarly journals Curbing action potential generation or ATP-synthase leads to a decrease in in-cell pyruvate dehydrogenase activity in rat cerebrum slices

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Benjamin Grieb ◽  
Sivaranjan Uppala ◽  
Gal Sapir ◽  
David Shaul ◽  
J. Moshe Gomori ◽  
...  
Keyword(s):  
Action Potential ◽  
Atp Synthase ◽  
Neural Activity ◽  
Pyruvate Dehydrogenase ◽  
Cerebral Metabolism ◽  
Neuronal Firing ◽  
Action Potential Generation ◽  
Potential Generation ◽  
Drastic Increase ◽  
Rat Cerebrum

AbstractDirect and real-time monitoring of cerebral metabolism exploiting the drastic increase in sensitivity of hyperpolarized 13C-labeled metabolites holds the potential to report on neural activity via in-cell metabolic indicators. Here, we followed the metabolic consequences of curbing action potential generation and ATP-synthase in rat cerebrum slices, induced by tetrodotoxin and oligomycin, respectively. The results suggest that pyruvate dehydrogenase (PDH) activity in the cerebrum is 4.4-fold higher when neuronal firing is unperturbed. The PDH activity was 7.4-fold reduced in the presence of oligomycin, and served as a pharmacological control for testing the ability to determine changes to PDH activity in viable cerebrum slices. These findings may open a path towards utilization of PDH activity, observed by magnetic resonance of hyperpolarized 13C-labeled pyruvate, as a reporter of neural activity.

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