To determine the role of striatal dopaminergic innervation on upper limb synergies during walking, we measured arm kinematics in 13 subjects with Parkinson disease. Patients were recruited according to several inclusion criteria to represent the best possible in vivo model of dopaminergic denervation. Of relevance, we included only subjects with normal spatio-temporal parameters of the stride a...

BACKGROUND Huntington's disease (HD) is a genetic disorder expressed by a degeneration of the basal ganglia inter alia accompanied with dopaminergic alterations. These dopaminergic alterations are related to genetic factors i.e., CAG-repeat expansion. The error (related) negativity (Ne/ERN), a cognitive event-related potential related to performance monitoring, is generated in the anterior cing...

Dopaminergic midbrain neurons are involved in many important brain functions including motor control, as well as emotive and cognitive tasks. They also play critical roles in major disorders likes Parkinson disease, schizophrenia, drug abuse and attention-deficit hyperactivity disorder. This bewildering diversity of distinct dopaminergic functions appears to be in contrast to the routinely assu...

bstract—The firing patterns of dopaminergic neurons in vivo re strongly modulated by afferent input. The principal GABAeric inputs to the dopaminergic neurons of the substantia nigra riginate from neurons of the neostriatum, globus pallidus and ubstantia nigra pars reticulata. It has previously been shown hat the firing pattern of nigral dopaminergic neurons can be anipulated by pharmacological...

1-Methyl-4-phenylpyridinium (MPP(+)) is selectively toxic to dopaminergic neurons and has been studied extensively as an etiologic model of Parkinson's disease (PD) because mitochondrial dysfunction is implicated in both MPP(+) toxicity and the pathogenesis of PD. MPP(+) can inhibit mitochondrial complex I activity, and its toxicity has been attributed to the subsequent mitochondrial depolariza...

This study analyzes the electrophysiological cause and behavioral consequence of dopaminergic cell loss in a knockin mouse strain bearing hypersensitive nicotinic alpha4-receptor subunits ("L9'S mice"). Adult brains of L9'S mice show moderate loss of substantia nigra dopaminergic neurons and of striatal dopaminergic innervation. Amphetamine-stimulated locomotion is impaired, reflecting a reduct...

Obesity causes hyperleptinemia. We have previously shown that D2 receptor-mediated inhibition of ventral tegmental area (VTA) dopaminergic neurons is attenuated in diet-induced mice with obesity. Consequently, we hypothesized that high concentrations of serum leptin during obesity might modulate D2 receptor-mediated effects on VTA dopaminergic neurons. To investigate our hypothesis, we examined...

Dopamine (DA) has been postulated to play a role in the loss of dopaminergic substantia nigra (SN) neurons in Parkinson's disease because of its propensity to oxidize and form quinones and other reactive oxygen species that can alter cellular function. Moreover, DA depletion can attenuate dopaminergic cell loss in vitro. To test the contribution of DA to SN impairment in vivo, we used DA-defici...

It is obvious that DA is an important neurotransmitter in vivo. It is involved in a variety of physiological processes such as mental processes, motor function and hormone regulation. In this context, it is quite understandable that a DA D2 receptor antagonist that inhibits the DA D2 receptor regardless of the state of activity of dopaminergic neurotransmission and inhibit the physiological fun...

Dopaminergic drugs can cause augmentation during the treatment of restless legs syndrome (RLS). We previously reported that sudden withdrawal of dopaminergic treatment was poorly tolerated. We now report our experience with gradual withdrawal of the dopaminergic drug during the drug substitution process using a retrospective chart review with comparison to previous data. Seven patients with RLS...