Journal: Proceedings of the National Academy of Sciences of the United States of America

Article Title: Single-molecule imaging of the functional crosstalk between surface NMDA and dopamine D1 receptors

doi: 10.1073/pnas.1310145110

Figure Lengend Snippet: The D1R–NMDAR interaction bidirectionally regulates the surface distribution and dynamics of D1R and NMDAR. (A) Immunostaining of surface D1R-CFP (green) and GluN1 subunit (red) in hippocampal neurons. The yellow arrow shows overlay. (B) Immunostaining of surface D1R-CFP in control or after D1/5R agonist, TAT-t2, or TAT-[N2A15] application. (Scale bar, 250 nm.) (C) Normalized measures of D1R-CFP clusters intensity in control (n = 32 neuronal fields), D1/5R agonist-treated (n = 24 neuronal fields; *P < 0.05 compared with control), TAT-NSt2–treated (non-sense of TAT-t2, n = 19 neuronal fields), TAT-t2–treated (n = 21 neuronal fields; **P < 0.01 compared with TAT-NSt2), TAT-NSt3–treated (non-sense of TAT-t3, n = 11 neuronal fields), TAT-t3–treated (n = 12 neuronal fields; P > 0.05 compared with TAT-NSt3), TAT-[NS15]–treated (n = 27 neuronal fields; P > 0.05), or TAT-[N2A15]–treated (n = 21 neuronal fields, *P < 0.05 compared with TAT-[NS15]) conditions. (D) Representative trajectories (1,000 frames, 20-Hz acquisition rate) of surface single D1R-CFP (Left) (green) (scale bar, 400 nm) and GluN1-NMDAR (Right) (blue) (scale bar, 300 nm) in the absence and presence of either D1/5R agonist (10 µM, 15 min) or TAT-t2 (10 µM, 15 min). Bold dotted line, perisynaptic area; thin dotted line, PSD area. (E) Plot of the MSD of surface D1R-CFP (Upper) (green) and GluN1-NMDAR (Lower) (blue) versus time in presence of TAT-NS or TAT-t2 peptides (10 µM, 15 min). The SEM is included for each data point (D1R: TAT-NS, n = 986 trajectories, and TAT-t2, n = 1,326; GluN1-NMDAR: TAT-NS, n = 198, and TAT-t2, n = 134). (F and G) Representative surface distributions of single D1R-CFP (green) (F) and GluN1-NMDAR (blue) (G) in the synaptic area (PSD + perisynaptic area) in control, D1/5R agonist, and TAT-t2 conditions. Each dot represents the detection of a single receptor during a frame. Comparisons of the time spent in the synaptic area (dwell time) by single D1R-CFP (control, n = 173 trajectories; D1/5R agonist, n = 142, **P < 0.01; TAT-t2, n = 752, *P < 0.05) (F) and GluN1-NMDAR (control, n = 189 trajectories; D1/5R agonist, n = 157, *P < 0.05; TAT-t2, n = 134, **P < 0.01) (G) and the synaptic fraction of detected single D1R-CFP (control, n = 14 neuronal fields; D1/5R agonist, n = 19, **P < 0.01; D1/5R agonist in the presence of dynasore, n = 47, **P < 0.01; TAT-t2, n = 15, ***P < 0.001) (F), D5R-CFP (n = 16, P > 0.05) (F), and GluN1-NMDAR (control, n = 11; D1/5R agonist, n = 15, *P < 0.05; TAT-t2, n = 14, *P < 0.05) (G). Dyn., dynasore; D1/5 ago., D1/5 receptor agonist SKF-38393.

Article Snippet: For single-nanoparticle tracking, QD 655 coupled to goat anti-rabbit F(ab′) 2 or anti-mouse IgG (Invitrogen) was incubated (1:10,000, 10 min) onto neurons previously exposed for 10 min to either mouse monoclonal anti-GFP (1 µg; Invitrogen), rabbit polyclonal anti-D1R (1 µg; Lifespan Biosciences), mouse monoclonal anti-GluA2:00 AMPAR subunit (1 µg; Millipore), or rabbit polyclonal anti–GluN1-NMDAR subunit (1 µg; Alomone Laboratories) antibodies.

Techniques: Immunostaining

Journal: Proceedings of the National Academy of Sciences of the United States of America

Article Title: Single-molecule imaging of the functional crosstalk between surface NMDA and dopamine D1 receptors

doi: 10.1073/pnas.1310145110

Figure Lengend Snippet: D1R activation or D1R/GluN1-NMDAR interaction blockade increases synaptic NMDAR content and favors AMPAR synaptic long-term potentiation. (A) (Left) Excitatory postsynaptic current traces recorded at −70 mV and +40 mV from a representative hippocampal CA1 pyramidal cell, before and 10 min after exposure to D1/5R agonist. (Right) Relative change over time of the AMPA/NMDA ratio at CA1 synapses in the absence or presence of D1/5R agonist (n = 13, *P < 0.05 10 min after agonist) and in the absence or presence of vehicle (n = 7, P > 0.05). (B) Surface imaging of GluN1-SEP in neurons incubated with either TAT-NS or TAT-t2 (10 µM). (Scale bar, 5 µm.) (Right) Average value of GluN1-SEP content in the synaptic area after TAT-NS or TAT-t2 application (n = 8 neurons per group, **P < 0.01). (C) Dendritic fragment of a hippocampal neuron expressing Homer 1c-DsRed (Upper) and GluA1-SEP (Lower). SEP only fluoresces at neutral pH when receptors are inserted at the plasma membrane. Ten minutes after chemical LTP induction (cLTP), the GluA1-SEP fluorescence intensity increased in postsynaptic clusters. (Insets) High magnification of a synaptic GluA1-SEP cluster. (Scale bar, 2 µm.) (D) Comparison of the synaptic GluA1-SEP fluorescence intensity before and after cLTP with prior TAT-NS (n = 198 synapses, *P < 0.05) or TAT-t2 (n = 215 synapses, *P < 0.05) (TAT-NS versus TAT-t2; *P < 0.05) application. (E) Schematic model of the D1R–NMDAR surface interplay in hippocampal neurons. D1Rs are highly diffusive at the neuronal surface and are dynamically retained in clusters in the vicinity of glutamate synapses where they interact with NMDAR. Dopamine release disrupts this interaction and favors the lateral redistribution of both receptors: D1Rs freely explore extrasynaptic areas, whereas NMDARs laterally reach the PSD where they impact on the long-term plasticity of glutamate synapses.

Article Snippet: For single-nanoparticle tracking, QD 655 coupled to goat anti-rabbit F(ab′) 2 or anti-mouse IgG (Invitrogen) was incubated (1:10,000, 10 min) onto neurons previously exposed for 10 min to either mouse monoclonal anti-GFP (1 µg; Invitrogen), rabbit polyclonal anti-D1R (1 µg; Lifespan Biosciences), mouse monoclonal anti-GluA2:00 AMPAR subunit (1 µg; Millipore), or rabbit polyclonal anti–GluN1-NMDAR subunit (1 µg; Alomone Laboratories) antibodies.

Techniques: Activation Assay, Imaging, Incubation, Expressing, Fluorescence

Journal: Neural Regeneration Research

Article Title: Mechanisms responsible for the effect of median nerve electrical stimulation on traumatic brain injury-induced coma: orexin-A-mediated N-methyl-D-aspartate receptor subunit NR1 upregulation

doi: 10.4103/1673-5374.184494

Figure Lengend Snippet: Effect of MNS on NR1 expression in the prefrontal cortex of rats with TBI-induced coma (western blot assay). Control group: Sham-operated rats (skin incision but no TBI). TBI group: Weight-drop method was used to establish a model of TBI. Stimulated group: Comatose rats with TBI underwent MNS. Antagonist group: Comatose rats with TBI and given MNS received an intracerebroventricular injection of the OX1R antagonist SB334867. Data are expressed as the mean ± SD ( n = 6 rats per time point per group). * P < 0.05, vs . control group; # P < 0.05, vs . TBI group; † P < 0.05, vs . stimulated group; § P < 0.05, vs . 6 h; ‡ P < 0.05, vs . 12 h (one-way analysis of variance). MNS: Electrical stimulation of the median nerve; TBI: traumatic brain injury; h: hours.

Article Snippet: The membranes were incubated with rabbit anti-NR1 polyclonal antibody (1:200; Wuhan Boster Biotechnology Co., Ltd., Wuhan, Hubei Province, China) and mouse anti-β-actin monoclonal antibody (1:500; Zhongshan Golden Bridge Biotechnology Co., Ltd., Beijing, China) overnight at 4°C, and washed in Tris buffered saline with Tween 20.

Techniques: Expressing, Western Blot, Control, Injection

Journal: Neural Regeneration Research

Article Title: Mechanisms responsible for the effect of median nerve electrical stimulation on traumatic brain injury-induced coma: orexin-A-mediated N-methyl-D-aspartate receptor subunit NR1 upregulation

doi: 10.4103/1673-5374.184494

Figure Lengend Snippet: Effect of MNS on NR1 immunoreactivity in the prefrontal cortex of rats with TBI-induced coma (× 400). Control group: Sham-operated rats (skin incision but no TBI). TBI group: Weight-drop method was used to establish a model of TBI. Stimulated group: Comatose rats with TBI underwent MNS. Antagonist group: Comatose rats with TBI and given MNS received an intracerebroventricular injection of the OX1R antagonist SB334867. Brown cells (red arrows) are NR1-immunoreactive. Positive immunostaining for NR1 was found in the cytoplasm, cell membrane, and nucleus of neurons in the prefrontal cortex. MNS: Electrical stimulation of the median nerve; TBI: traumatic brain injury; h: hours.

Article Snippet: The membranes were incubated with rabbit anti-NR1 polyclonal antibody (1:200; Wuhan Boster Biotechnology Co., Ltd., Wuhan, Hubei Province, China) and mouse anti-β-actin monoclonal antibody (1:500; Zhongshan Golden Bridge Biotechnology Co., Ltd., Beijing, China) overnight at 4°C, and washed in Tris buffered saline with Tween 20.

Techniques: Control, Injection, Immunostaining, Membrane