Nigrostriatal Tract/Pathway

Nigrostriatal Tract/Pathway Anti-Parkinson Drugs... 

Nicotinic Acetylcholine Receptor Nicotinic Receptors Nigrostriatal Tract/Pathway Nitrates... 

The nigrostriatal tract is one of the four main dopaminergic pathways in the central nervous system. About 75% of the dopamine in the brain occurs in the nigrostriatal pathway with its cell bodies in the substantia nigra, whose axons project in the corpus striatum. Degeneration of the dopaminergic neurons in the nigrostriatal system results in Parkinsons disease. 

People with Parkinson s disease show a specific degeneration of the nigrostriatal tract so DA must be linked in some way to the control of motor function. It is also known that an imbalance of DA function on the two sides of the rat brain, either by stimulation or lesion of one SN, causes off-line or rotational movement (Ungerstadt and Arbuthnott 1970). This is best shown some days after 6-OHDA lesion of one substantia nigra and its nigrostriatal pathway when systemic apomorphine (DA agonist) causes animals to turn away from the lesioned side (contraversive), presumably... 

Unlike many chemicals in the brain, neurotransmitters are not homogeneously distributed, but concentrated in certain regions. For example, almost two-thirds of the dopamine in the brain is found in the bilateral nigrostriatal (mesostriatal) tract (pathway), where the neuronal cell bodies are located in the substantia nigra and the axons terminate in the corpus striatum. When over 85% of these dopaminergic neurons are lost, the characteristic motor dysfunction of Parkinson s disease is seen. 

Nigrostriatal tract The major dopaminergic neuronal pathway linking midbrain and forebrain basal ganglia. 

Parkinson s disease is a disorder of the basal nuclei in the brain. Post-mortem studies of brains from patients with Parkinson s disease have shown greatly decreased levels of dopamine in the basal nuclei. The main pathology is degeneration of the dopaminergic neurons of the pathway from the substantia nigra in the brain stem to the corpus striatum (the nigrostriatal tract). 

The nigrostriatal pathway participates in the production of smooth physical motion. It is not the brain area that works to initiate movement, which is in the cerebral cortex (pyramidal tract) it is the region that helps one to have fluid motion (extrapyramidal tract). Although many neurotransmitters are found in this latter system, two neurotransmitters—dopamine and acetylcholine—are predominantly involved in this pathway. The brain normally maintains a relatively stable ratio of dopamine and acetylcholine in the pathway. However, when something happens to upset this ratio, problems arise. 

There are three major central DA pathways the nigrostriatal, which is affiliated with motor effects produced by antipsychotic drugs the tuberoinfundibular tract, which is asso-... 

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