Margot Ferreira

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Animal models with partial lesions of the dopaminergic nigrostriatal pathway may be useful for developing neuroprotective and neurotrophic therapies for Parkinson's disease. To develop such a model, different doses of 6-hydroxydopamine (0.0, 0.625, 1.25, 2.5 and 5.0 micrograms/microliters in 3.5 microliters of saline) were unilaterally injected into the(More)
The purpose of our study was to test the hypothesis that 5-hydroxytryptamine (5-HT)(1A) receptor agonists counteract morphine-induced respiratory depression. Studies were conducted in anesthetized rats, and respiratory activity was monitored with diaphragm electromyography. Morphine was administered i.v. in doses that produce apnea. Once apnea was(More)
1. To examine the effects of glucose on the central components of the vago-vagal reflex control of gastric function, we performed both in vivo and in vitro experiments on neurones in the medial nucleus of the tractus solitarius (mNTS) and in the dorsal motor nucleus of the vagus (DMV). 2. In the in vivo anaesthetized rat preparation, unilateral(More)
The purpose of this study was to investigate the effect of microinjection of nicotine and nicotinic receptor antagonists into the dorsal motor nucleus of the vagus (DMV) or medial subnucleus of the tractus solitarius (mNTS) on intragastric (IGP) and arterial blood pressures (BP) in anesthetized rats. Nicotine microinjected into the DMV (10-300 pmol)(More)
Neuronal nicotinic acetylcholine receptors (nAChRs) play a significant role in sympathetic transmission in the superior cervical ganglia (SCG), with most of the signal carried by a nAChR containing an alpha3 subunit. Work has shown that transection of the postganglionic nerves (axotomy) of the SCG results in a decrease in mRNA transcripts for alpha3,(More)
The present study demonstrates that the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) causes significantly greater reductions in striatal dopamine levels in C57/bl mice than in CD-1 mice, thus confirming a greater sensitivity of the C57/bl mice to MPTP. To determine the possible reasons for this difference in MPTP sensitivity between these(More)
It has been shown that nicotine prevents the loss of dopamine (DA) in the corpus striatum (CS) after 6-hydroxydopamine injection in the substantia nigra. To study the role of the enzyme tyrosine hydroxylase (TH; EC in this experimental paradigm, we have examined its activity by assessing the accumulation of l-3,4-dihydroxyphenylalanine after(More)
In vitro autoradiography using 125I-alpha-bungarotoxin (alpha-BGTx) and anti-alpha7 immunohistochemistry were performed on the dorsal motor nucleus of the vagus (DMV) of sham and chronically vagotomized rats to determine whether the alpha7-nicotinic acetylcholine receptor (nAChR) is located postsynaptically on DMV neurons whose axons contribute to the vagus(More)
Parkinson's disease (PD) is characterized mainly by a loss of nigrostriatal dopamine neurons. Thus far, the actual physiopathology of PD remains uncertain, although recent studies have found decreased activity of complex I, one of the enzymatic units of the mitochondrial respiratory chain, in various tissues of PD patients. Because most, if not all, of PD(More)
Adenosine receptor antagonists, DMPX, PACPX and theophylline, produce contralateral rotations in unilateral 6-hydroxydopamine-lesioned rats. DMPX and theophylline markedly increase rotations produced by bromocriptine (a dopamine D2 receptor agonist) and/or SKF38393A (a dopamine D1 receptor agonist). All of these effects are inhibited by CGS21680C (an(More)