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001-es BibID:BIBFORM060223
Első szerző:Bordás Csilla
Cím:The M-current contributes to high threshold membrane potential oscillations in a cell type-specific way in the pedunculopontine nucleus of mice / Bordas Csilla, Kovacs Adrienn, Pal Balazs
Dátum:2015
ISSN:1662-5102
Megjegyzések:The pedunculopontine nucleus is known as a cholinergic nucleus of the reticular activating system, participating in regulation of sleep and wakefulness. Besides cholinergic neurons, it consists of GABAergic and glutamatergic neurons as well. According to classical and recent studies, more subgroups of neurons were defined. Groups based on the neurotransmitter released by a neuron are not homogenous, but can be further subdivided. The PPN neurons do not only provide cholinergic and non-cholinergic inputs to several subcortical brain areas but they are also targets of cholinergic and other different neuromodulatory actions. Although cholinergic neuromodulation has been already investigated in the nucleus, one of its characteristic targets, the M-type potassium current has not been described yet. Using slice electrophysiology, we provide evidence in the present work that cholinergic neurons possess M-current, whereas GABAergic neurons lack it. The M-current contributes to certain functional differences of cholinergic and GABAergic neurons, as spike frequency adaptation, action potential firing frequency or the amplitude difference of medium afterhyperpolarizations (AHPs). Furthermore, we showed that high threshold membrane potential oscillation with high power, around 20 Hz frequency is a functional property of almost all cholinergic cells, whereas GABAergic neurons have only low amplitude oscillations. Blockade of the M-current abolished the oscillatory activity at 20 Hz, and largely diminished it at other frequencies. Taken together, the M-current seems to be characteristic for PPN cholinergic neurons. It provides a possibility for modulating gamma band activity of these cells, thus contributing to neuromodulatory regulation of the reticular activating system.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
M-current
Neuromodulation
oscillatory activity
pedunculopontine nucleus
spike frequency adaptation
Megjelenés:Frontiers in Cellular Neuroscience. - 9 (2015), Article ID 121. -
További szerzők:Kovács Adrienn (1989-) (molekuláris biológus) Pál Balázs (1975-) (élettanász)
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DOI
Intézményi repozitóriumban (DEA) tárolt változat
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2.

001-es BibID:BIBFORM062728
Első szerző:Kovács Adrienn (molekuláris biológus)
Cím:Direct presynaptic and indirect astrocyte-mediated mechanisms both contribute to endocannabinoid signaling in the pedunculopontine nucleus of mice / Kovács A., Bordás Cs., Bíró T., Hegyi Z., Antal M., Szücs P., Pál B.
Dátum:2017
ISSN:1863-2653 1863-2661
Megjegyzések:The pedunculopontine nucleus (PPN), a cholinergic nucleus of the reticular activating system, is known to be involved in the regulation of sleep and wakefulness. Endogenous and exogenous cannabinoids, either by systemic or local administration to the pedunculopontine nucleus can both influence sleep. We previously demonstrated that activation of astrocytes by cannabinoid type 1 (CB1) receptor agonists was able to modulate the membrane potential of PPN neurons, even in the presence of blockers of fast synaptic neurotransmission. In the present work we provide evidence that synaptic inputs of PPN neurons are also affected by activation of presynaptic and astrocytic CB1 receptors.Using slice electrophysiology combined with calcium imaging, optogenetics and immunohistochemistry, we revealed a direct presynaptic inhibitory action on inhibitory postsynaptic currents, along with a mild increase of excitatory postsynaptic currents during CB1 receptor stimulation. Besides inhibition of excitatory and inhibitory neurotransmission through stimulation of presynaptic CB1 receptors, astrocyte- and mGluR-dependent tonic inhibition and excitation also developed. The mild stimulatory action of CB1 receptor activation on excitatory neurotransmission is the combination of astrocyte-dependent tonic excitation on excitatory neurons and the canonical presynaptic CB1 receptor activation and consequential inhibition of excitatory synaptic neurotransmission, whereas the astrocyte-dependent stimulatory action was not observed on inhibitory neurotransmission within the PPN.Our findings demonstrate that endocannabinoids act in the PPN via a dual pathway, consisting of a direct presynaptic and an indirect, astrocyte-mediated component, regulating synaptic strength and neuronal activity via independent mechanisms.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
pedunculopontine nucleus
CB1 receptor
optogenetics
astrocyte
neuromodulation
Megjelenés:Brain Structure & Function 222 : 1 (2017), p. 247-266. -
További szerzők:Bordás Csilla Bíró Tamás (1968-) (élettanász) Hegyi Zoltán (1983-) (molekuláris biológus) Antal Miklós (1951-) (orvos, anatómus) Szűcs Péter (1974-) (kutatóorvos) Pál Balázs (1975-) (élettanász)
Pályázati támogatás:Nemzeti Agykutatási Program KTIA_13_NAP-A-I/10
Egyéb
Nemzeti Agykutatási Program KTIA_NAP_13-1-2013-0001
Egyéb
Nemzeti Agykutatási Program KTIA_NAP_13-2-2014-0005
Egyéb
MTA-TKI 242
MTA
TÁMOP-4.2.2.B-15/1/KONV-2015-0001
TÁMOP
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
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3.

001-es BibID:BIBFORM060026
Első szerző:Kovács Adrienn (molekuláris biológus)
Cím:Cholinergic and endocannabinoid neuromodulatory effects overlap on neurons of the pedunculopontine nucleus of mice / Adrienn Kovács, Csilla Bordás, Balázs Pál
Dátum:2015
Megjegyzések:The pedunculopontine nucleus (PPN) is a part of the reticular activating system and one of the main sources of the cholinergic fibers in the midbrain, while it is also subject to cholinergic modulation. This nucleus is known to be a structure that controls sleep-wake cycles, arousal, and locomotion. Neurons of the PPN are targets of several neuromodulatory mechanisms, which elicit heterogeneous pharmacological responses including hyperpolarization and depolarization, whereas lack of response can also be observed. In agreement with previous findings, we found that PPN neurons respond to the muscarinic agonist carbachol in a heterogeneous manner: they were depolarized and showed increased firing rate, decreased firing frequency, and were hyperpolarized, or showed no response. The heterogeneity of the muscarinic activation was similar to our previous observations with type 1 cannabinoid (CB1) receptor agonists; therefore, we investigated whether muscarinic and endocannabinoid modulatory mechanisms elicit the same action on a certain neuron. To achieve this, whole-cell patch clamp experiments were conducted on midbrain slices containing the PPN. Carbachol was applied first and, after recording the changes in the membrane potential and the firing frequency and achieving washout, the CB1 receptor agonist arachidonyl-2'-chloroethylamide (ACEA) was applied. A marked but not full overlap was observed: all neurons depolarized by carbachol were depolarized by the CB1 receptor agonist ACEA, and all neurons lacking response to carbachol lacked response to ACEA as well. However, neurons hyperpolarized by carbachol were depolarized, hyperpolarized, or not affected by the ACEA. These results indicate that endocannabinoid and muscarinic modulatory effects involve similar mechanisms of action.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
CB1 receptor
Muscarinic
Carbachol
arachidonyl-2'-chloroethylamide
reticular activating system
Megjelenés:Neuroreport. - 26 : 5 (2015), p. 273-278. -
További szerzők:Bordás Csilla Pál Balázs (1975-) (élettanász)
Internet cím:Szerző által megadott URL
DOI
Intézményi repozitóriumban (DEA) tárolt változat
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