Neuroinflammation is a process in which the brain responds to infections, diseases and injuries [1, 2]. Neuroinflammation involve two types of immune cells: lymphocytes, monocytes and macrophages of the hematopoietic system, and microglial cells of the CNS [3, 4]. Neuroinflammation disrupts the blood-brain barrier (BBB), allowing cells from the hematopoietic system to leave the blood stream and come in contact to the injury site [5]. The immune cells respond to injuries by eliminating debris and, synthesizing and releasing a host of powerful regulatory substances, like the complements, cytokines, chemokines, glutamate, interleukins, nitric oxide, reactive oxygen species and transforming growth factors [6-10]. The substances have both beneficial and harmful effects on the cellular environment, creating further damages [11] (fig. 1). Mature astrocytes are also activated following injury to the CNS [12, 13].
Chronic inflammation during depressive episodes could predispose depressive patients to neurodegenerative diseases, later in life [29].
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