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Figure 3 | Molecular Pain

Figure 3

From: Pre-injury administration of morphine prevents development of neuropathic hyperalgesia through activation of descending monoaminergic mechanisms in the spinal cord in mice

Figure 3

Involvement of descending monoaminergic pathways for the pre-injury morphine-induced analgesic effects. A,B: Pre-injury morphine (10 mg/kg. s.c.)-induced analgesia in thermal paw withdrawal (A) and mechanical paw pressure (B) tests were blocked by i.t. pretreatment with 3 nmol of serotonergic antagonist methysergide (Meth) or 10 nmol of adrenergic antagonist phentolamine (Phen). C: Dose-dependent pre-emptying effects induced by pre-injury i.t. injection of adrenergic agonist clonidine and serotonin uptake inhibitor fluoxetine in thermal paw withdrawal test. Thermal paw withdrawal latencies (PWL) or mechanical paw withdrawal thresholds (PWT) were measured 7 days following nerve injury. 'Morph' is morphine. Each data represents mean ± SE from 6–7 mice; *p < 0.05 compared with the group receiving vehicle as pretreatment.

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