scholarly journals Effects of muscarinic and nicotinic receptors on contextual modulation in macaque area V1

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jose L. Herrero ◽  
Alexander Thiele
Keyword(s):  
Receptor Antagonist ◽  
Contrast Sensitivity ◽  
Nicotinic Receptor ◽  
Single Cells ◽  
Receptor Blockade ◽  
Lateral Interactions ◽  
Contextual Modulation ◽  
Cortex Area ◽  
Higher Visual Areas ◽  
Muscarinic And Nicotinic Receptors

AbstractContext affects the salience and visibility of image elements in visual scenes. Collinear flankers can enhance or decrease the perceptual and neuronal sensitivity to flanked stimuli. These effects are mediated through lateral interactions between neurons in the primary visual cortex (area V1), in conjunction with feedback from higher visual areas. The strength of lateral interactions is affected by cholinergic neuromodulation. Blockade of muscarinic receptors should increase the strength of lateral intracortical interactions, while nicotinic blockade should reduce thalamocortical feed-forward drive. Here we test this proposal through local iontophoretic application of the muscarinic receptor antagonist scopolamine and the nicotinic receptor antagonist mecamylamine, while recording single cells in parafoveal representations in awake fixating macaque V1. Collinear flankers generally reduced neuronal contrast sensitivity. Muscarinic and nicotinic receptor blockade equally reduced neuronal contrast sensitivity. Contrary to our hypothesis, flanker interactions were not systematically affected by either receptor blockade.

Arginine vasopressin produces renal vasodilation via V2 receptors in conscious dogs

1993 ◽  
Vol 265 (4) ◽  
pp. R934-R942 ◽  
Author(s):  
M. Naitoh ◽  
H. Suzuki ◽  
M. Murakami ◽  
A. Matsumoto ◽  
A. Ichihara ◽  
...  
Keyword(s):  
Cardiac Output ◽  
Receptor Antagonist ◽  
Arginine Vasopressin ◽  
Statistical Significance ◽  
Conscious Dogs ◽  
Receptor Blockade ◽  
Vasodilatory Response ◽  
V2 Receptor ◽  
Plasma Arginine ◽  
V2 Receptor Antagonist

In conscious dogs, 36-h water deprivation induced a significant increase in renal blood flow (RBF) with elevation of the plasma arginine vasopressin (AVP) concentration to 9.6 +/- 1.8 pg/ml. To simulate such a condition, a mild elevation of plasma AVP was produced by infusing AVP intravenously at a dose of 0.1 ng.kg-1.min-1 for 20 min. The plasma AVP concentration then increased to 6.8 +/- 0.7 pg/ml. This dose of AVP increased the RBF by 21.7 +/- 2.6% and decreased the renal vascular resistance by 18.1 +/- 2.3% without significant changes in mean arterial pressure, cardiac output, or heart rate. The mechanism of this renal vasodilatory action was examined using newly developed, orally effective, selective AVP antagonists OPC-21268 (a V1-receptor antagonist) and OPC-31260 (a V2-receptor antagonist). In 36-h water-deprived dogs, V2-receptor blockade with OPC-31260 significantly decreased the RBF by 20.5 +/- 2.6% without significant changes in cardiac output. The exogenous AVP-induced renal vasodilatory response tended to be augmented when V1 receptors were blocked by pretreatment with OPC-21268, but the change did not achieve statistical significance. On the other hand, V2-receptor blockade by either pretreatment with OPC-31260 or simultaneous infusion of OPC-31260 inhibited this vasodilatory response. Furthermore, intravenous infusion of 1-desamino-8-D-arginine vasopressin (DDAVP) at a dose of 0.3 ng.kg-1 x min-1 for 20 min significantly increased the RBF by 36.5 +/- 1.7%, and this DDAVP-induced renal vasodilation was inhibited by simultaneous infusion of V2-receptor antagonist.(ABSTRACT TRUNCATED AT 250 WORDS)

Nicotinic and M1-, M2-muscarinic cholinergic control of ACTH response to insulin-induced hypoglycaemia in man

1987 ◽  
Vol 116 (4) ◽  
pp. 531-536 ◽  
Author(s):  
V. Coiro ◽  
M. Passeri ◽  
G. Gelmini ◽  
C. Davoli ◽  
G. Bianconcini ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Nicotinic Receptor ◽  
Insulin Injection ◽  
Tolerance Test ◽  
Injection Time ◽  
Nicotinic Cholinergic Receptors ◽  
Muscarinic Cholinergic ◽  
Normal Men ◽  
Nicotinic Receptor Antagonist ◽  
Acth Release

Abstract. The possible mediation of muscarinic and/or nicotinic-cholinergic receptors in the response of ACTH to insulin-induced hypoglycaemia was evaluated in 18 normal men. Subjects were tested with the insulin (0.15 U/kg) tolerance test (ITT) in basal conditions and in the presence of the M1- and M2-muscarinic antagonist atropine (600 μg iv just before insulin injection (time 0) plus 600 μg 20 min later in 6 subjects) or the M1-muscarinic receptor blocker pirenzepine (40 mg iv 10 min before ITT or 20 mg at time 0 plus 30 mg at time 20 in 6 subjects). The remaining 6 men were treated with the nicotinic receptor antagonist trimethaphan (0.3 mg/min × 30 min before ITT). ACTH rose 4.7 times in response to hypoglycaemia. The ACTH response to hypoglycaemia did not change after pirenzepine administration, whereas it was significantly increased by atropine and decreased by trimethaphan treatment. These data indicate that nicotinic and muscarinic (M2 but not M1) receptors participate in a different manner in the regulation of the hypoglycaemia-induced ACTH release.

Histamine-induced modulation of olfactory receptor neurones in two species of lobster, Panulirus argus and Homarus americanus

1989 ◽  
Vol 145 (1) ◽  
pp. 133-146 ◽  
Author(s):  
T. A. Bayer ◽  
T. S. McClintock ◽  
U. Grunert ◽  
B. W. Ache
Keyword(s):  
Receptor Antagonist ◽  
Olfactory Receptor ◽  
Single Cells ◽  
Homarus Americanus ◽  
Chloride Ions ◽  
Electrophysiological Recording ◽  
Stimulus Response ◽  
Olfactory Receptor Cells ◽  
Receptor Cells ◽  
The One

In two species of lobster, application of the biogenic amine, histamine (HA), to the soma of olfactory receptor cells suppressed both spontaneous and odour-evoked activity, as shown by electrophysiological recording from single cells. The action of HA was graded, reversible, specific to HA, and had a threshold between 0.1 and 1 mumol l-1. HA increased the conductance of the membrane, primarily to chloride ions. The vertebrate HA receptor antagonist, cimetidine, and the nicotinic receptor antagonist, d-tubocurarine, but not other known vertebrate HA receptor antagonists, reversibly blocked the action of HA. These results suggest that a histaminergic mechanism modulates stimulus-response coupling in lobster olfactory receptor cells and potentially implicate a novel HA receptor, pharmacologically similar to the one recently described in the visual system of flies.

Selective ETA vs. dual ETA/B receptor blockade for the prevention of sunitinib-induced hypertension and albuminuria in WKY rats

2019 ◽  
Vol 116 (10) ◽  
pp. 1779-1790 ◽  
Author(s):  
Katrina M Mirabito Colafella ◽  
Karla B Neves ◽  
Augusto C Montezano ◽  
Ingrid M Garrelds ◽  
Richard van Veghel ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Renal Injury ◽  
Angiogenesis Inhibitor ◽  
Receptor Blockade ◽  
Receptor Antagonism ◽  
Sunitinib Treatment ◽  
Wky Rats ◽  
Induced Hypertension ◽  
Eta Receptor ◽  
Stimulation Of

Abstract Aims Although effective in preventing tumour growth, angiogenesis inhibitors cause off-target effects including cardiovascular toxicity and renal injury, most likely via endothelin (ET)-1 up-regulation. ET-1 via stimulation of the ETA receptor has pro-hypertensive actions whereas stimulation of the ETB receptor can elicit both pro- or anti-hypertensive effects. In this study, our aim was to determine the efficacy of selective ETA vs. dual ETA/B receptor blockade for the prevention of angiogenesis inhibitor-induced hypertension and albuminuria. Methods and results Male Wistar Kyoto (WKY) rats were treated with vehicle, sunitinib (angiogenesis inhibitor; 14 mg/kg/day) alone or in combination with macitentan (ETA/B receptor antagonist; 30 mg/kg/day) or sitaxentan (selective ETA receptor antagonist; 30 or 100 mg/kg/day) for 8 days. Compared with vehicle, sunitinib treatment caused a rapid and sustained increase in mean arterial pressure of ∼25 mmHg. Co-treatment with macitentan or sitaxentan abolished the pressor response to sunitinib. Sunitinib did not induce endothelial dysfunction. However, it was associated with increased aortic, mesenteric, and renal oxidative stress, an effect that was absent in mesenteric arteries of the macitentan and sitaxentan co-treated groups. Albuminuria was greater in the sunitinib- than vehicle-treated group. Co-treatment with sitaxentan, but not macitentan, prevented this increase in albuminuria. Sunitinib treatment increased circulating and urinary prostacyclin levels and had no effect on thromboxane levels. These increases in prostacyclin were blunted by co-treatment with sitaxentan. Conclusions Our results demonstrate that both selective ETA and dual ETA/B receptor antagonism prevents sunitinib-induced hypertension, whereas sunitinib-induced albuminuria was only prevented by selective ETA receptor antagonism. In addition, our results uncover a role for prostacyclin in the development of these effects. In conclusion, selective ETA receptor antagonism is sufficient for the prevention of sunitinib-induced hypertension and renal injury.

scholarly journals Ventral hippocampal α7 and α4β2 nicotinic receptor blockade and clozapine effects on memory in female rats

2006 ◽  
Vol 188 (4) ◽  
pp. 597-604 ◽  
Author(s):  
Ana Pocivavsek ◽  
Laura Icenogle ◽  
Edward D. Levin
Keyword(s):  
Nicotinic Receptor ◽  
Female Rats ◽  
Receptor Blockade

scholarly journals Neuronal basis of perceptual learning in striate cortex

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Zhen Ren ◽  
Jiawei Zhou ◽  
Zhimo Yao ◽  
Zhengchun Wang ◽  
Nini Yuan ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Perceptual Learning ◽  
Contrast Sensitivity ◽  
Striate Cortex ◽  
Signal To Noise Ratio ◽  
High Spatial Frequency ◽  
Sensitivity Training ◽  
Spatial Frequencies ◽  
Cortex Area ◽  
Adult Cats

Abstract It is well known that, in humans, contrast sensitivity training at high spatial frequency (SF) not only leads to contrast sensitivity improvement, but also results in an improvement in visual acuity as assessed with gratings (direct effect) or letters (transfer effect). However, the underlying neural mechanisms of this high spatial frequency training improvement remain to be elucidated. In the present study, we examined four properties of neurons in primary visual cortex (area 17) of adult cats that exhibited significantly improved acuity after contrast sensitivity training with a high spatial frequency grating and those of untrained control cats. We found no difference in neuronal contrast sensitivity or tuning width (Width) between the trained and untrained cats. However, the trained cats showed a displacement of the cells’ optimal spatial frequency (OSF) to higher spatial frequencies as well as a larger neuronal signal-to-noise ratio (SNR). Furthermore, both the neuronal differences in OSF and SNR were significantly correlated with the improvement of acuity measured behaviorally. These results suggest that striate neurons might mediate the perceptual learning-induced improvement for high spatial frequency stimuli by an alteration in their spatial frequency representation and by an increased SNR.

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