Restoring Spinal Noradrenergic Inhibitory Tone Attenuates Pain Hypersensitivity in a Rat Model of Parkinson’s Disease

Figure 8

Effects of L-DOPA and pramipexole on thermal and mechanical hypersensitivity in 6-OHDA-lesioned rats. On the 5th week after microinjection of 6-OHDA, (a) systemic application of L-DOPA (15 mg/kg, i.p.) did not significantly inhibit thermal (a) and mechanical hypersensitivity ((b)–(d)) in the 6-OHDA-lesioned rats, although there was a trend to increase the paw thermal withdrawal threshold ( = 5-6 for each group). ((e)–(h)) Systemic application of pramipexole (PRA; 1 mg/kg, i.p.) significantly increased the paw thermal withdrawal threshold (e) after injection 1.5 h, but it had no effects on mechanical hypersensitivity ((f)–(h)) in the 6-OHDA-lesioned rats ( compared to the saline control, = 5–7 for each group).

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