Central Dopaminergic System and Its Implications in Stress-Mediated Neurological Disorders and Gastric Ulcers: Short Review

Table 2

Modulation of dopaminergic pathways and their associated changes of dopamine levels in neurological disorders.

DA pathways	DA alterations	Disorders	References
Nigrostriatal	DA decrease	Parkinson’s disease	[42–45]
		Huntington’s disease	[43, 44]
		ADHD	[46]
	DA increase	Schizophrenia	[43]
		Tourette’s syndrome	[47]
		ADHD	[43]
Mesocortical	DA increase	Schizophrenia	[43]
		Tourette’s syndrome	[43]
Mesolimbic	DA decrease	Epilepsy	[48, 49]
		Drug addiction	[43, 50]
	DA increase	Obesity	[43, 50]
		Depression	[50]
Tuberoinfundibular	DA decrease	Pituitary tumors	[51]

There are four major dopaminergic pathways: (1) nigrostriatal pathway, in which substantia nigra neurons innervate the stratum; (2) nesocortical pathway, which links the ventral tegmental area to medial prefrontal, cingulate, and entorhinal cortices; (3) nesolimbic pathway, composed of ventral tegmental area cells projecting to the nucleus accumbens and other limbic areas; (4) tuberoinfundibular, which projects from arcuate and periventricular nuclei of the hypothalamus to the pituitary gland. Abbreviations: DA: dopamine; ADHD: attention-deficit hyperactivity disorder.