Unilateral lesions of mesostriatal dopaminergic pathway alters the withdrawal response of the rat hindpaw to mechanical stimulation

Characterization of nociceptive response to chemical, mechanical, and thermal stimuli in adolescent rats with neonatal dopamine depletion

“…Since the direct dopaminergic projection from VTA exerts an inhibitory effect on electrical responses in the prefrontal cortex to mechanical noxious stimulation (Sogabe et al, 2013), the ascending dopaminergic projections should be considered to forward the future experiments. Previous studies have shown the effects of dopamine depletion during adulthood on nociceptive responses (Saade´et al, 1997;Takeda et al, 2005;Tassorelli et al, 2007;Chudler and Lu, 2008); however, these results were not always consistent with those of the present study. Decreased latency of withdrawal responses to mechanical and/or thermal stimuli has been observed in the hemi-Parkinson rat model (Takeda et al, 2005;Chudler and Lu, 2008), as also has the hyperalgesic response to a formalin injection (Tassorelli et al, 2007;Chudler and Lu, 2008).…”

“…Previous studies have shown the effects of dopamine depletion during adulthood on nociceptive responses (Saade´et al, 1997;Takeda et al, 2005;Tassorelli et al, 2007;Chudler and Lu, 2008); however, these results were not always consistent with those of the present study. Decreased latency of withdrawal responses to mechanical and/or thermal stimuli has been observed in the hemi-Parkinson rat model (Takeda et al, 2005;Chudler and Lu, 2008), as also has the hyperalgesic response to a formalin injection (Tassorelli et al, 2007;Chudler and Lu, 2008). The discrepancy between the results of the present and previous studies is attributable to the anatomical extent (unilateral or bilateral lesion in the dopaminergic neural system) and developmental period (adulthood or neonatal) of dopamine depletion.…”

“…These clinical reports are also supported by experimental data, as detailed below. Rats with unilateral 6-hydroxydopamine (6-OHDA)-induced lesions in the nigrostriatal dopaminergic neurons show hypersensitivity to mechanical (Saadeé t al., 1997;Takeda et al, 2005) and thermal (Saadeé t al., 1997;Chudler and Lu, 2008) stimuli. Furthermore, unilateral 6-OHDA-treated rats exhibited hyperalgesic response to pain-inducing chemical stimuli (Tassorelli et al, 2007;Chudler and Lu, 2008).…”

Reduced Presynaptic Dopamine Activity in Fibromyalgia Syndrome Demonstrated With Positron Emission Tomography: A Pilot Study

“…41 Degradation of ventral tegmental area function has been shown to result in enhancement of nociceptive behaviors 42,50,57 as well as the development of mechanical hyperalgesia. 60 As noted above, a reduction in substantia nigra dopamine neurons is the central pathology of Parkinson's disease, with which FMS shares a number of clinical features, including autonomic dysfunction, 28 genitourinary 54 and gastrointestinal dysfunction, 29 sleep disturbances, 34, 46 frequent psychiatric involvement, 35 and mysterious musculoskeletal pains. 15,20,65 A potential linkage between the dopamine abnormalities reported herein and these various clinical phenomena is therefore suggested by these data.…”

Monoaminergic Antidepressants in the Relief of Pain: Potential Therapeutic Utility of Triple Reuptake Inhibitors (TRIs)

“…For example, it has been shown that a unilateral lesion of the nigrostriatal pathways causes hyperalgesic responses to painful stimuli at contralateral side [64,87-89]. As well, DA depletion by 6-OHDA injection into the medial forebrain bundle, CPu and SN results in hypersensitivity to mechanical [90,91], electrical [92] and thermal stimulation [91]. A recent study found hyperalgesic responses to painful chemical stimulation of the hind paw ipsilateral to intrastriatal 6-OHDA administration [88].…”