Measurement of immobility in the bar-hang test following pallidal infusion of the dopamine receptor antagonist and agonist.

<p>(A) Cannula placement was confirmed in fixed brains, and four out of 63 rats were excluded from the final data analysis due to incorrect cannula placement. The bar-hang test consisted of 3 blocks with 20-min intervals. Vehicle, raclopride (B; 0.5 and 2.0 µg per site) or quinpirole (QUIN) (C; 10.0 µg per site) was bilaterally injected into the globus pallidus of EGF and control (CON) rats after block #1. In each session we measured the latency until one of the paws of rats was removed from the horizontal bar (mean ± SEM, N = 8–9 rats each). *P<0.05, **P<0.01, ***P<0.001, compared with vehicle-infused control rats; +P<0.05, ++P<0.01, +++P<0.001, compared with the value of session #1 by Fisher's LSD. Note: The pallidal infusion of the D2-like receptor agonist to control rats (green star) significantly reduced the latency.