Fig. 4. Combined Ghsr1α/Drd1 activation rescues hippocampal synapse in vitro.

(A) Effect of different treatments (1.5 μM MK0677, 2 μM SKF81297, or in combination) on synaptic density in hippocampal neurons in the presence or absence of oligomeric Aβ42 (1 μM, 24 hours). ***P < 0.001 vehicle-treated versus oligomeric Aβ42–treated groups, two-way ANOVA followed by Bonferroni post hoc analysis. Data were collected from three independent experiments. n = 30 to 48 neurites. (B) Representative 3D reconstructed images of synapse staining. vGLUT1 (blue) and PSD95 (red) were used to visualize pre- and postsynaptic terminals, respectively. The dendrites were stained with MAP2 (green). The overlaid staining of vGLUT1/PSD95 identifies synapses. (C) Effect of different treatments (1.5 μM MK0677, 2 μM SKF81297, or in combination) on Ghsr1α/Drd1 complex in hippocampal neurons in the presence or absence of oligomeric Aβ42 (1 μM, 24 hours). **P < 0.01 and ***P < 0.001 vehicle-treated versus oligomeric Aβ42-treated groups, two-way ANOVA followed by Bonferroni post hoc analysis. Data were collected from three independent experiments. n = 8 to 10 neurons. (D) Representative images of Ghsr1α/Drd1 PLA-positive dots. (E) Time course of LTP and representative fEPSP responses during the baseline period (black trace) and 30 s after theta burst simulation (red trace) in five treatment groups at 4 months of age. **P < 0.01 5×FAD MK0677/SKF81297 versus 5×FAD saline, one-way ANOVA followed by Bonferroni post hoc analysis. nonTg saline, n = 9; 5×FAD saline, n = 10; 5×FAD MK0677/SKF81297, n = 7; 5×FAD MK0677, n = 9; and 5×FAD SKF81297, n = 9. (F to H) mEPSC frequency (F) and amplitude (G) in the indicated groups of 4-month-old mice. *P < 0.05 and **P < 0.01, one-way ANOVA followed by Bonferroni post hoc analysis. n = 6. (H) Representative traces of mEPSC recordings.