Facilitation of glutamate and GABA release by P2X receptor activation in supraoptic neurons from freshly isolated rat brain slices

Vavra, Vojtech; Bhattacharya, Anirban; Zemková, Hana

doi:10.1016/j.neuroscience.2011.04.067

Cited by 49 publications

(75 citation statements)

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“…Suramin (100 M, 10 s) almost completely blocked the ATP-induced response, but this antagonist alone had a strong inhibitory effect on GABAergic sIPSCs (data not shown) because this compound also inhibits GABA receptor channels (Nakazawa et al, 1995;Vavra et al, 2011). The preapplication of PPADS (10 M, 30 s) inhibited the ATP-increased frequency of sIPSCs by 71 Ϯ 9% (Fig.…”

Section: Pharmacological Characterization Of Presynaptic P2x Receptormentioning

confidence: 79%

“…Hypothalamic slices (200-to 300-m-thick) containing SCN were cut with a vibratome (DTK-1000, D.S.K. Dosaka) and incubated as described previously (Kretschmannova et al, 2003;Vavra et al, 2011). Briefly, the slices were allowed to recover for at least 1 h in oxygenated ACSF at 32°C-33°C before being transferred into a recording chamber.…”

Section: Methodsmentioning

confidence: 99%

“…The SCN regions were dissected from ϳ600-m-thick hypothalamic slices, and the cells were dissociated after treatment with trypsin according to the published method (Watanabe et al, 1993). Next, the cells were purified on discontinuous protein gradient, ϳ100,000 cells were placed on coverslips coated with 1% poly-L-lysine solution (Sigma) in 35 mm culture dishes (BD Falcon) and cultured in Neurobasal medium with 2% B27 supplement and 0.5 mM L-glutamine (all from Invitrogen) in a humidified CO 2 -containing atmosphere at 37°C until the use (7 d).…”

Section: Methodsmentioning

confidence: 99%

“…Figure 2A (top row) shows that the P2X2R expression is absent on cell bodies of SCN neurons. To demonstrate the specificity of the P2X2R antibody, we performed parallel experiments on slices containing supraoptic nuclei (SON), which are known to express functional P2X2Rs Vulchanova et al, 1996;Vavra et al, 2011). A large number of cell bodies throughout the SON was intensely stained for the P2X2R (Fig.…”

Section: Expression Of Mrna and Protein For Purinergic P2 Receptors Imentioning

confidence: 99%

“…Adenosine has been shown to inhibit glutamatergic retinohypothalamic neurotransmission via presynaptic adenosine A1 receptors in the SCN of hamster (Hallworth et al, 2002) and mouse (Sigworth and Rea, 2003). P2XRs are highly expressed throughout the hypothalamus Vulchanova et al, 1996;Kanjhan et al, 1999;Guo et al, 2009), where ATP, coreleased with neuropeptides, appears to be involved in the regulation of hormone secretion (Troadec et al, 1998;Kapoor and Sladek, 2000;Stojilkovic, 2009) and control of specific autonomic functions, including the central mechanism of body temperature regulation (Gourine et al, 2002), for example. The expression of P2X2, P2X4, and P2X6 receptor mRNAs and the P2X5R protein (Xiang et al, 2006) has also been found in the rat SCN; however, there is no information available regarding other P2XR subtypes and the function of these receptors in the SCN.…”

Section: Introductionmentioning

confidence: 99%

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Potentiation of Inhibitory Synaptic Transmission by Extracellular ATP in Rat Suprachiasmatic Nuclei

et al. 2013

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The hypothalamic suprachiasmatic nuclei (SCN), the circadian master clock in mammals, releases ATP in a rhythm, but the role of extracellular ATP in the SCN is still unknown. In this study, we examined the expression and function of ATP-gated P2X receptors (P2XRs) in the SCN neurons of slices isolated from the brain of 16-to 20-day-old rats. Quantitative RT-PCR showed that the SCN contains mRNA for P2X 1-7 receptors and several G-protein-coupled P2Y receptors. Among the P2XR subunits, the P2X2 Ͼ P2X7 Ͼ P2X4 mRNAs were the most abundant. Whole-cell patch-clamp recordings from SCN neurons revealed that extracellular ATP application increased the frequency of spontaneous GABAergic IPSCs without changes in their amplitudes. The effect of ATP appears to be mediated by presynaptic P2X2Rs because ATP␥S and 2MeS-ATP mimics, while the P2XR antagonist PPADS blocks, the observed enhancement of the frequency of GABA currents. There were significant differences between two SCN regions in that the effect of ATP was higher in the ventrolateral subdivision, which is densely innervated from outside the SCN. Little evidence was found for the presence of P2XR channels in somata of SCN neurons as P2X2R immunoreactivity colocalized with synapsin and ATP-induced current was observed in only 7% of cells. In fura-2 AM-loaded slices, BzATP as well as ADP stimulated intracellular Ca 2ϩ increase, indicating that the SCN cells express functional P2X7 and P2Y receptors. Our data suggest that ATP activates presynaptic P2X2Rs to regulate inhibitory synaptic transmission within the SCN and that this effect varies between regions.

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Section: Pharmacological Characterization Of Presynaptic P2x Receptormentioning

confidence: 79%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Expression Of Mrna and Protein For Purinergic P2 Receptors Imentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Potentiation of Inhibitory Synaptic Transmission by Extracellular ATP in Rat Suprachiasmatic Nuclei

et al. 2013

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Magnocellular Neurons and Posterior Pituitary Function

Brown

2016

Comprehensive Physiology

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The posterior pituitary gland secretes oxytocin and vasopressin (the antidiuretic hormone) into the blood system. Oxytocin is required for normal delivery of the young and for delivery of milk to the young during lactation. Vasopressin increases water reabsorption in the kidney to maintain body fluid balance and causes vasoconstriction to increase blood pressure. Oxytocin and vasopressin secretion occurs from the axon terminals of magnocellular neurons whose cell bodies are principally found in the hypothalamic supraoptic nucleus and paraventricular nucleus. The physiological functions of oxytocin and vasopressin depend on their secretion, which is principally determined by the pattern of action potentials initiated at the cell bodies. Appropriate secretion of oxytocin and vasopressin to meet the challenges of changing physiological conditions relies mainly on integration of afferent information on reproductive, osmotic, and cardiovascular status with local regulation of magnocellular neurons by glia as well as intrinsic regulation by the magnocellular neurons themselves. This review focuses on the control of magnocellular neuron activity with a particular emphasis on their regulation by reproductive function, body fluid balance, and cardiovascular status. © 2016 American Physiological Society. Compr Physiol 6:1701-1741, 2016.

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P2X7 Receptors in Neurohypophysial Terminals: Evidence for their Role in Arginine‐Vasopressin Secretion

Cuadra

Custer

Bosworth

et al. 2013

Journal Cellular Physiology

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Arginine-vasopressin (AVP) plays a major role in maintaining cardiovascular function and related pathologies. The mechanism involved in its release into the circulation is complex and highly regulated. Recent work has implicated the purinergic receptor, P2X7R, in a role for catecholamine-enhanced AVP release in the rat hypothalamic-neurohypophysial (NH) system. However, the site of P2X7R action in this endocrine system and whether or not it directly mediates release in secretory neurons have not been determined. We hypothesized that the P2X7R is expressed and mediates AVP release in NH terminals. P2X7R function was first examined by patch-clamp recordings in isolated NH terminals. Results revealed that subpopulations of isolated terminals displayed either high ATP-sensitivity or low ATP-sensitivity, the latter of which was characteristic of the rat P2X7R. Additional recordings showed that terminals showing sensitivity to the P2X7R-selective agonist, BzATP, were further inhibited by P2X7R selective antagonists, AZ10606120 and brilliant blue-G. In confocal micrographs from isolated terminals of the NH showed that P2X7R-immunoreactivity was localized in the plasma membranes. Lastly, the role of P2X7R on AVP release was tested. Our results showed that BzATP evoked sustained AVP release in NH terminals, which was inhibited by AZ10606120. Taken together, our data lead us to conclude that the P2X7R is expressed in NH terminals and corroborates its role in AVP secretion.

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Facilitation of glutamate and GABA release by P2X receptor activation in supraoptic neurons from freshly isolated rat brain slices

Cited by 49 publications

References 39 publications

Potentiation of Inhibitory Synaptic Transmission by Extracellular ATP in Rat Suprachiasmatic Nuclei

Potentiation of Inhibitory Synaptic Transmission by Extracellular ATP in Rat Suprachiasmatic Nuclei

Magnocellular Neurons and Posterior Pituitary Function

P2X7 Receptors in Neurohypophysial Terminals: Evidence for their Role in Arginine‐Vasopressin Secretion

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