**2. Definitions**

Neurotoxicity of anesthetic substances on the developing brain is determined by a reduction in neural density and apoptosis in experimental studies and by disturbances in memory, attention, learning, and motor activity in clinical studies [4–6]. Although anesthetic agents used in neonates have known neurotoxic effects, there are valid reasons for using these agents even in vulnerable patients. Because pain itself has a neurotoxic effect, anesthesia-analgesia application in painful conditions may have a net neuroprotective effect [7, 8]. It should also be noted that in cases of hypoxia-ischemia or trauma, administration of anesthetics reduces the infarct volume by reducing the metabolic rate, decreasing intracranial pressure, eliminating free oxygen radicals, and reducing secondary injury [9–11]. Another positive effect is neuroplasticities. These are described as the neurophysical and neurochemical ability to improve compliance against environmental changes and damage when used in depressive disorders and diseases. Neuroplasticity refers to the increase in intercellular connections. Agents that enhance neuroplasticity have raised new hope for the treatment of neurodegenerative diseases [12–14].
