Journal: Cerebral cortex (New York, N.Y. : 1991)

Article Title: The HIV-1 viral protein Tat increases glutamate and decreases GABA exocytosis from human and mouse neocortical nerve endings.

doi: 10.1093/cercor/bhp274

Figure Lengend Snippet: Figure 3. Effects of 3,5-DHPG on [3H]D-ASP and [3H]GABA-evoked exocytosis from human neocortical synaptosomes: antagonism by CPCCOEt or MPEP and western blot analysis of mGlu1/5 receptor proteins. (A) Kþ (12 mM)-evoked release of [3H]D-ASP. (B) Kþ (12 mM)-evoked release of [3H]GABA. Results are expressed as induced overflow. Time course relationship of the 12 mM Kþ-evoked release of [3H]D-ASP (C) and [3H]GABA (D) in the absence (gray circles) and in the presence (black circles) of 50 lM 3,5DHPG. Results are expressed as % of total tritium content. When not shown, error bars are within graph symbols. Data are means ± standard error of the mean of 4 (A, C) and 3 (B, D) experiments run in triplicate. *P \ 0.05 at least versus 12 mM Kþ; §P \ 0.05 at least versus 12 mM Kþ/1 lM MPEP; #P \ 0.05 at least versus respective 12 mM Kþ-evoked neurotransmitter release (expressed as % of total tritium content). (E) Western blot analysis of mGlu1 and mGlu5 receptor proteins in DS-Syn fractions isolated from human neocortical synaptosomes. The figure represents a western blot comparing the mGlu1 and mGlu5 receptor immunor- eactivities in a fraction enriched in human neocortical synaptosomal membranes. Anti-Stx-1A was used as a selective neuronal marker; 25-lg protein/lane were applied to the SDS-PAGE gel. Protein weights are in kDa. The blot in the figure is representative of 4 blots from synaptosomal preparations obtained from different patients, in different days.

Article Snippet: Veratridine, o-(carboximethyl)hydroxylamine hemihydrochloride, anti-GFAP monoclonal mouse purified immunoglobulin G (IgG) and Protease Inhibitor Cocktail were purchased from Sigma Aldrich Inc. (St Louis, MO). (RS)-3,5-d3,5-DHPG, 2-methyl-6-(phenylethynyl) pyridine hydrochloride (MPEP), and CPCCOEt were obtained from Tocris Cookson (Bristol, UK).

Techniques: Western Blot, Isolation, Marker, SDS Page

Journal: The Journal of Neuroscience

Article Title: Synaptic Plasticity in the Amygdala in a Model of Arthritic Pain: Differential Roles of Metabotropic Glutamate Receptors 1 and 5

doi: 10.1523/JNEUROSCI.23-01-00052.2003

Figure Lengend Snippet: Differential changes of mGluR1- and mGluR5-mediated effects in the arthritis pain model. A, In a CeA neuron recorded in a brain slice from a normal rat, MPEP (1 μm; mGluR5 antagonist) inhibited synaptic transmission, whereas CPCCOEt (10 μm; mGluR1 antagonist) had no effect.B, In a CeA neuron from an arthritic rat (6 hr after induction), both CPCCOEt and MPEP inhibited synaptic transmission, suggesting a change in the endogenous activation of mGluR1 in the arthritis pain model. Each trace is the average of 8–10 monosynaptic EPSCs recorded at –60 mV. Drugs were applied by superfusion of the slice in ACSF for at least 10 min. Data shown were recorded at 10–12 min. C, CPCCOEt inhibited synaptic transmission in neurons from arthritic rats (EC50, 94 nm;n = 9) but not in neurons from normal rats (n = 11), suggesting a change in the activation state of mGluR1 in the arthritis pain model.D, Analysis of the raw data (EPSC peak amplitude in picoamperes) shows that blocking of mGluR1 by CPCCOEt significantly reduced the increased EPSC amplitude in CeA neurons from arthritic rats to control levels measured in neurons from nonarthritic rats.E, The inhibitory effects of MPEP on synaptic transmission in CeA neurons were not significantly different in normal rats (EC50, 28.3 nm;n = 10) and in arthritis (EC50, 27.7 nm;n = 9; p> 0.05; two-way ANOVA). F, Analysis of the raw data (picoamperes) shows that MPEP reduced a larger portion of the increased EPSC in arthritis than in control neurons; however, the MPEP-insensitive component of the EPSC also increased in arthritis. ***p < 0.001; unpaired ttest.

Article Snippet: Analysis of the concentration–response relationships showed that CPCCOEt (mGluR1 antagonist) (Fig. C ) inhibited synaptic transmission at the PB→CeA synapse in the arthritis pain model (EC 50 , 94 n m ; n = 9 neurons) (Fig. C , filled circles ), whereas CPCCOEt had no significant effect on synaptic transmission under normal conditions; i.e., the slope of the concentration-response curve was not significantly different from zero ( p > 0.05; F (1,3) = 6.482; n = 11; linear regression analysis, Prism 3.0, GraphPad software) (Fig. C , open circles ).

Techniques: Slice Preparation, Transmission Assay, Activation Assay, Blocking Assay, Control

Journal: The Journal of Neuroscience

Article Title: Activation of Metabotropic Glutamate Receptor 5 Has Direct Excitatory Effects and Potentiates NMDA Receptor Currents in Neurons of the Subthalamic Nucleus

doi: 10.1523/jneurosci.20-21-07871.2000

Figure Lengend Snippet: Figure 8. mGluR5 mediates group I mGluR-induced potentiation of NMDA-evoked currents. A, Current traces of NMDA-evoked currents before, during, and after application of DHPG (100 mM). The potentiation is blocked by MPEP (10 mM) but not CPCCOEt (100 mM). B, Mean data 6 SEM of percent potentiation of NMDA-evoked currents by DHPG over predrug conditions. MPEP (10 mM) significantly blocks potentiation of NMDA-evoked current compared with DHPG alone (*p , 0.05).

Article Snippet: We thank Dr. Carmelo Romano (Washington University) for supplying anti-mGluR1a and anti-mGluR5 antibodies, Dr. Darryle Schoepp and Dr. James Monn (Eli Lilly) for supplying LY354740, Dr. Rainer Kuhn (Novartis) for supplying MPEP and CPCCOEt, and Stephanie Carter for valuable technical assistance.

Techniques:

Journal: The Journal of Neuroscience

Article Title: Activation of Metabotropic Glutamate Receptor 5 Has Direct Excitatory Effects and Potentiates NMDA Receptor Currents in Neurons of the Subthalamic Nucleus

doi: 10.1523/jneurosci.20-21-07871.2000

Figure Lengend Snippet: Figure 7. mGluR5 mediates group I mGluR-evoked depolarization of STN neurons. A, Membrane potential traces showing depolarization with DHPG (100 mM), which is blocked by the mGluR5-selective antagonist MPEP (10 mM). Membrane depolarization is not blocked by the mGluR1- selective antagonist CPCCOEt (100 mM). B, Mean data 6 SEM of change in membrane potential showing a significant inhibition of DHPG-mediated depolarization of STN neurons by MPEP (10 mM) compared with DHPG alone (**p , 0.001). MPEP also significantly blocks depolarization medi- ated by the mGluR5-selective agonist CBPG (100 mM) (*p , 0.05).

Article Snippet: We thank Dr. Carmelo Romano (Washington University) for supplying anti-mGluR1a and anti-mGluR5 antibodies, Dr. Darryle Schoepp and Dr. James Monn (Eli Lilly) for supplying LY354740, Dr. Rainer Kuhn (Novartis) for supplying MPEP and CPCCOEt, and Stephanie Carter for valuable technical assistance.

Techniques: Membrane, Inhibition