Midbrain dopaminergic and hindbrain serotonergic neurons play an important role in the modulation of behavior and are involved in a series of neuropsychiatric disorders. Despite the importance of these cells, little is known about the molecular mechanisms governing their development. During embryogenesis, midbrain dopaminergic neurons are specified rostral to the midbrain-hindbrain organizer (M...

Abstract Introduction Mesodiencephalic dopamine neurons play crucial roles in the control of a variety of brain functions, including voluntary movement and behavioural processes such as mood, reward, and attention. Degeneration of mesodiencephalic dopaminergic neurons also represents one of the principal pathological features of Parkinson’s disease. Recent progress led to the identification of ...

In both Parkinson disease and in animal models of Parkinson disease, there is a microglial reaction in addition to the loss of dopaminergic neurons in the ventral midbrain. To determine the pathological role of this microglial reaction, we analyzed the kinetics of microglial activation and dopaminergic cell death induced in rats with the neurotoxin 6-hydroxydopamine. As early as Day 1 after the...

This study analyzes the electrophysiological cause and behavioral consequence of dopaminergic cell loss in a knock-in mouse strain bearing hypersensitive nicotinic 4 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 reduction ...

Nowadays it is assumed that besides its roles in neuronal processing, dopamine (DA) is also involved in the regulation of cerebral blood flow. However, studies on the hemodynamic actions of DA have been mainly focused on the cerebral cortex, but the possibility that vessels in deeper brain structures receive dopaminergic axons and the origin of these axons have not been investigated. Bearing in...

Neurogenesis continues in the adult forebrain subventricular zone (SVZ) and the dentate gyrus of the hippocampal formation. Degeneration of dopaminergic projections in Parkinson's disease and animals reduces, whereas ciliary neurotrophic factor (CNTF) promotes, neurogenesis. We tested whether the dopaminergic system promotes neurogenesis through CNTF. Astrocytes of the SVZ and dentate gyrus exp...

Parkinson's disease (PD) affects >1 million Americans and is marked by the loss of dopaminergic neurons in the substantia nigra. PD has been linked to two causative factors: genetic risks (hereditary PD) and environmental toxins (idiopathic PD). In recent years, considerable effort has been devoted to the development of a Drosophila model of human PD that might be useful for examining the cellu...

Useful information in the visual environment is often contained in specific conjunctions of visual features (e.g., color and shape). The ability to quickly and accurately process such conjunctions can be learned. However, the neural mechanisms responsible for such learning remain largely unknown. It has been suggested that some forms of visual learning might involve the dopaminergic neuromodula...

The Dopaminergic System is believed to be of central importance to the brain processes involved in the development of human addiction to psychoactive substances (Parsons et al. 1991; Robinson and Berridge 1993). Study of animal models of addiction has revealed that mesocorti-colimbic dopaminergic pathways are necessary for the establishment of repetitive self-administration of psychoactive drug...

Human embryonic stem cells (hESCs) are a potential source of dopaminergic neurons for treatment of patients with Parkinson's disease (PD). Dopaminergic neurons can be derived from hESCs and display a characteristic midbrain phenotype. Once transplanted, they can induce partial behavioral recovery in animal models of PD. However, the potential research field faces several challenges that need to...