scholarly journals Role of epinephrine in 5HT 1A receptor agonist‐mediated increase in venous tone during hypovolemic shock

2010 ◽  
Vol 24 (S1) ◽  
Author(s):  
Ruslan L Tiniakov ◽  
Karie E Scrogin
Keyword(s):  
Receptor Agonist ◽  
Hypovolemic Shock ◽  
Venous Tone

Intra-median raphe nucleus (MRN) infusions of muscimol, a GABA-A receptor agonist, reinstate alcohol seeking in rats: role of impulsivity and reward

2007 ◽  
Vol 195 (4) ◽  
pp. 605-615 ◽  
Author(s):  
Anh Lê Dzung ◽  
Douglas Funk ◽  
Stephen Harding ◽  
Walter Juzytsch ◽  
Zhaoxia Li ◽  
...  
Keyword(s):  
Receptor Agonist ◽  
Raphe Nucleus ◽  
Median Raphe ◽  
Median Raphe Nucleus ◽  
Gaba A ◽  
Median Raphé ◽  
Alcohol Seeking

GABAA and GABAC Receptors Have Contrasting Effects on Excitability in Superior Colliculus

1999 ◽  
Vol 82 (4) ◽  
pp. 2020-2023 ◽  
Author(s):  
Michael Pasternack ◽  
Mathias Boller ◽  
Belinda Pau ◽  
Matthias Schmidt
Keyword(s):  
Superior Colliculus ◽  
Receptor Agonist ◽  
Brain Slices ◽  
Superficial Layer ◽  
Field Potentials ◽  
Competitive Antagonist ◽  
Postsynaptic Potential ◽  
Late Potential ◽  
Receptor Agonists And Antagonists

We have recently found that GABAC receptor subunit transcripts are expressed in the superficial layers of rat superior colliculus (SC). In the present study we used immunocytochemistry to demonstrate the presence of GABAC receptors in rat SC at protein level. We also investigated in acute rat brain slices the effect of GABAA and GABAC receptor agonists and antagonists on stimulus-evoked extracellular field potentials in SC. Electrical stimulation of the SC optic layer induced a biphasic, early and late, potential in the adjacent superficial layer. The late component was completely inhibited by 6-cyano-7-nitroquinoxaline-2,3-dione or CoCl2, indicating that it was generated by postsynaptic activation. Muscimol, a potent GABAA and GABAC receptor agonist, strongly attenuated this postsynaptic potential at concentrations >10 μM. In contrast, the GABAC receptor agonist cis-aminocrotonic acid, as well as muscimol at lower concentrations (0.1–1 μM) increased the postsynaptic potential. This increase was blocked by (1,2,5,6-tetrahydropyridine-4-yl)methylphosphinic acid, a novel competitive antagonist of GABAC receptors. Our findings demonstrate the presence of functional GABAC receptors in SC and suggest a disinhibitory role of these receptors in SC neuronal circuitry.

scholarly journals Role of some types of serotonin receptors in murine hypophyseal-testicular complex activation induced by the presence of a female

2003 ◽  
Vol 49 (6) ◽  
pp. 53-56
Author(s):  
T. G. Amstislavskaya ◽  
N. K. Popova
Keyword(s):  
Serotonin Receptors ◽  
Receptor Agonist ◽  
Serotonin Receptor ◽  
Receptive Female ◽  
Plasma Testosterone ◽  
Blood Levels ◽  
Inhibitory Effects ◽  
Sexual Activation ◽  
Different Types

Placement of a sexually receptive female mouse behind a partition that prevents physical contacts, but permits it to see and smell caused an increase in the blood levels of testosterone in male mice. The selective 5-HTIA-serotonin receptor agonist 08-OH- DPAT (0.1 mg/kg) and the mixed 5-HTIA/IB agonist eltoprazine, 3.0 and 10.0 mg/kg, blocked the activating effect of female exposure on the male pituitary-testicular system. The 5-HT/-receptor agonist p-MPPI (0.2 mg/kg) prevented the inhibitory effects of 8-OH-DPATand eltoprazine. The 5-HT/B-receptor agonist CGS- 12066A (1.0 and 2.0 mg/kg) exerted no effect while the mixed 5-HTIB/2C-receptor agonist TFMPP (5.2 mg/kg) inhibited a female-induced increase in the levels of male blood testosterone. The 5-HT/-receptor agonist keranserin (1.0 and 2.0 mg/kg) prevented a female-induced increase in the levels of testosterone. The 5-HT3-receptor agonist ondansetron (0.05 and 0.1 mg/kg) elevated the baseline level of plasma testosterone, but blocked receptive female-induced activation of the male hypothalamic-pituitary-testicular system (HPTS). It is concluded that 5-HTIA-receptors are involved in the control of male sexual activation. At the same time different types and even subtypes of the same type of 5-HT-receptors produce varying inhibitory and activating effects on the receptive female-induced activation of HPTS. Blocking of the female-induced activation of HPTS seems to be realized by involving 5-HTu- and 5-HT2C-receptors and its activation occurs with the participation of 5-HT^- and 5- HT3-receptors.

Muscarinic presynaptic modulation in GABAergic pallidal synapses of the rat

2015 ◽  
Vol 113 (3) ◽  
pp. 796-807 ◽  
Author(s):  
Ricardo Hernández-Martínez ◽  
José J. Aceves ◽  
Pavel E. Rueda-Orozco ◽  
Teresa Hernández-Flores ◽  
Omar Hernández-González ◽  
...  
Keyword(s):  
Receptor Agonist ◽  
Projection Neurons ◽  
Quantal Content ◽  
Short Term ◽  
Paired Pulse ◽  
Short Term Plasticity ◽  
Striatal Projection Neurons ◽  
Muscarinic Cholinergic ◽  
Muscarinic Modulation

The external globus pallidus (GPe) is central for basal ganglia processing. It expresses muscarinic cholinergic receptors and receives cholinergic afferents from the pedunculopontine nuclei (PPN) and other regions. The role of these receptors and afferents is unknown. Muscarinic M1-type receptors are expressed by synapses from striatal projection neurons (SPNs). Because axons from SPNs project to the GPe, one hypothesis is that striatopallidal GABAergic terminals may be modulated by M1 receptors. Alternatively, some M1 receptors may be postsynaptic in some pallidal neurons. Evidence of muscarinic modulation in any of these elements would suggest that cholinergic afferents from the PPN, or other sources, could modulate the function of the GPe. In this study, we show this evidence using striatopallidal slice preparations: after field stimulation in the striatum, the cholinergic muscarinic receptor agonist muscarine significantly reduced the amplitude of inhibitory postsynaptic currents (IPSCs) from synapses that exhibited short-term synaptic facilitation. This inhibition was associated with significant increases in paired-pulse facilitation, and quantal content was proportional to IPSC amplitude. These actions were blocked by atropine, pirenzepine, and mamba toxin-7, suggesting that receptors involved were M1. In addition, we found that some pallidal neurons have functional postsynaptic M1 receptors. Moreover, some evoked IPSCs exhibited short-term depression and a different kind of modulation: they were indirectly modulated by muscarine via the activation of presynaptic cannabinoid CB1 receptors. Thus pallidal synapses presenting distinct forms of short-term plasticity were modulated differently.

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