Fig. 5: Sensory rebound – Effect of muscimol injection in the substantia nigra pars reticulata on the parabrachial nucleus firing rate and nociceptive responses.
From: Altered parabrachial nucleus nociceptive processing may underlie central pain in Parkinson’s disease
a Peri-stimulus histograms and raster sweeps showing individual examples of nociceptive responses recorded in a Total DA lesion rat simultaneously in the SNr (top) and PBN (bottom), before (left) and after (right) muscimol injection in the SNr. The red line represents the onset of the noxious footshock. b Individual plots of the mean (±SEM, Hz) firing rate (top) and nociceptive response magnitude (bottom) before (pre) and after (post) muscimol injection in the SNr measured in the Sham (blue), Partial (orange) and Total (red) DA lesion groups. Note that this injection has no significant effect on PBN activity in the Sham group while both DA lesion groups presented a strong sensory and firing rate rebound.
