Manuel Emilio Zuñiga Rodriguez

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Insight into the organization of the basal ganglia in the normal, parkinsonian and L-dopa-induced dyskinesia states is critical for the development of newer and more effective therapies for Parkinson's disease. We believe that the basal ganglia can no longer be thought of as a unidirectional linear system that transfers information based solely on a(More)
The basal ganglia (BG) are a highly organized network, where different parts are activated for specific functions and circumstances. The BG are involved in movement control, as well as associative learning, planning, working memory, and emotion. We concentrate on the "motor circuit" because it is the best understood anatomically and physiologically, and(More)
Progressive loss of the ascending dopaminergic projection in the basal ganglia is a fundamental pathological feature of Parkinson's disease. Studies in animals and humans have identified spatially segregated functional territories in the basal ganglia for the control of goal-directed and habitual actions. In patients with Parkinson's disease the loss of(More)
The electrophysiological and neurochemical characteristics of the nondopaminergic nigrostriatal (NO-DA) cells and their functional response to the degeneration of dopaminergic nigrostriatal (DA) cells were studied. Three different criteria were used to identify NO-DA cells: (1) antidromic response to striatal stimulation with an electrophysiological(More)
Parkinson's disease is a neurodegenerative process characterized by numerous motor and nonmotor clinical manifestations for which effective, mechanism-based treatments remain elusive. Here we discuss a series of critical issues that we think researchers need to address to stand a better chance of solving the different challenges posed by this pathology.
Movement asymmetry in humans and animals is often considered as being induced by the brain lateralization of the motor system. In the present work, the hemispheric asymmetry for motor planning as a cause of behavioral lateralization was examined. This study was carried out on normal volunteers and patients suffering unilateral brain damage caused by a(More)
The substantia nigra (SN) is a midbrain center composed of dopaminergic (DA-) and gamma aminobutyric acid (GABA)ergic (GABA-) neurons. In this study, we investigated the topographical relationship between both cell populations and their chemical profile by using single and double immunostaining for tyrosine hydroxylase (TH), glutamic acid decarboxylase(More)
Although dopamine has been considered as the only neurotransmitter in the nigrostriatal pathway, studies carried out in the last two decades have suggested the existence of a nondopaminergic nigrostriatal projection, and more recently, gamma-aminobutyric acid (GABA) has been identified as its neurotransmitter. In this study, we used the combination of(More)
Recent studies have reported population right-biased lateralization in rats, although with low percentages (between 54-59%). The present study investigated the spatial preference of rats in an electrified T-maze during successive days and the influence of ascending dopaminergic systems using apomorphine, a dopamine agonist, as well as ipsilateral and(More)
The aim of this study was to investigate the interaction between beta-amyloid (Abeta) peptide and astrogliosis in early stages of Abeta toxicity. In Wistar rats, anaesthetised with equitesine, a single microinjection of Abeta1-42 oligomers was placed into the retrosplenial cortex. Control animals were injected with Abeta42-1 peptide into the corresponding(More)