In the rat model, 6-hydroxydopamine (6-OHDA) known as a selective catecholaminergic neurotoxin used chiefly in modeling Parkinson's disease (PD). Continuous aerobic exercise and curcumin supplementations could play a vital role in neuroprotection. This study aimed to explore the neuroprotective roles of regular aerobic exercise and curcumin during PD. For this, rats were treated as follows for 8 consecutive weeks (5 d in a week): For this, animals were orally treated with curcumin (50 ml/kg) alone or in combination with aerobic exercise. Compared with a control group, induction of PD by 6-OHDA increased the amount of α-synuclein protein and malondialdehyde levels and decreased the number of substantia nigra neurons, total antioxidant capacity, and glutathione peroxidase activity in brain tissue. All these changes were abolished by the administration of curcumin with aerobic exercise treatments. Activity behavioral tests also confirmed the above-mentioned results by increasing the rod test time and the number of rotations due to apomorphine injection. Histopathology assays mimic the antioxidant activity and behavioral observations. Combined curcumin with aerobic exercise treatments is potentially an effective strategy for modifying the dopaminergic neuron dysfunction in 6-OHDA-induced rats modeling PD via dual inhibiting oxidative stress indices and regulating behavioral tasks.
Breathing impairments, such as an alteration in breathing
pattern, dyspnoea, and sleep apnoea, are common health deficits
recognised in Parkinson’s disease (PD). The mechanism that
underlies these disturbances, however, remains unclear. We
investigated the effect of the unilateral damage to the rat
nigrostriatal pathway on the central ventilatory response to
hypercapnia, evoked by administering 6-hydroxydopamine
(6-OHDA) into the right medial forebrain bundle (MFB). The
respiratory experiments were carried out in conscious animals in
the plethysmography chamber. The ventilatory parameters were
studied in normocapnic and hyperoxic hypercapnia before and
14 days after the neurotoxin injection. Lesion with the 6-OHDA
produced an increased tidal volume during normoxia. The
magnified response of tidal volume and a decrease of breathing
frequency to hypercapnia were observed in comparison to the
pre-lesion and sham controls. Changes in both respiratory
parameters resulted in an increase of minute ventilation of the
response to CO2 by 28 % in comparison to the pre-lesion state
at 60 s. Our results demonstrate that rats with implemented
unilateral PD model presented an altered respiratory pattern
most often during a ventilatory response to hypercapnia.
Preserved noradrenaline and specific changes in dopamine and
serotonin characteristic for this model could be responsible for
the pattern of breathing observed during hypercapnia.
The present review brings the survey of the most frequently used behavioural tests in experimental models of Parkinson's disease (PD). Although there is no spontaneous occurrence of parkinsonism in animals, several experimental animal models of PD have been developed to achieve the same clinical features in animals. The techniques employing neurotoxins in lesioning the nigrostriatal dopaminergic (DA) system have a large selectivity and reproducibility. The most frequently used neurotoxins are l-methyl-4-phenyl-l,2,3,6-tetrahydropyridine (MPTP) and 6-hydroxydopamine (6-OHDA). MPTP-lesioned monkeys mimic best the symptomatology of PD in human patients while rats appear to be refractory to MPTP. For that reason, 6-OHDA is used to damage the substantia nigra in a rodent model. Behavioural tests of animals with nigrostriatal lesion represent valuable non- invasive methods for assessing the influence of damaged DA system on locomotor activity. The most frequently used experimental model of PD is the drug-evoked rotation in 6-OHDA unilaterally lesioned rats. This model produces well-defined and stable behavioural deficits. The rotation test is a useful parameter for evaluating imbalances of dopamine in both striata of the hemi-parkinsonian rat model. T-maze, treadmill running test or sensorimotor tests are used to evaluate spontaneous locomotor activity of lesioned animals. Skilled motor tasks measure the influence of dopamine-depleting lesions on complex motor acts. Transplantation of DA tissue into the striatum offers a new approach to the treatment of PD. Experimental models and behavioural tests are used to evaluate the extent of graft-induced recovery of MPTP- or 6-OHDA-lesioned animals. Different results obtained after the use of different tests reflect the level of graft integration into the host circuitry.
The negative affective state of opiate abstinence plays an important role in craving and relapse to compulsive drug use. The dopamine system participates in the reward effects of opiate use and the aversive effect of opiate abstinence. The amygdala is an essential neural substrate for associative learning of emotion. To establish a model of conditioned place aversion (CPA) in morphine-treated rats, we used different visual and tactual cues as conditioned stimuli (CS) within a conditioning apparatus. An injection of naloxone served as the unconditioned stimulus (US). The 6-hydroxydopamine (6-OHDA) lesion technique was used to investigate the effects of the dopaminergic system of the central nucleus of the amygdala (CeA) on naloxone-induced CPA. Rats were rendered physically dependent via administration of increasing doses of morphine delivered via intraperitoneal injection. Doses increased by 20 % each day for 14 days, starting from an initial dose of 6 mg/kg. All rats also received a low dose of naloxone (0.1 mg/kg) by injection 4 hours after morphine treatment on days 11 and 13 to induce CPA in a biased twocompartment conditioned place apparatus. Morphine-dependent rats with sham lesions were found to develop significant CPA after naloxone treatment. Bilateral 6-OHDA lesions of the CeA impaired the acquisition of CPA but had no effect on locomotor activity. These results suggest that the dopaminergic system of the CeA plays an important role in the negative affective state of opiate abstinence., W. Xu ... [et al.]., and Obsahuje seznam literatury