Acute histological effects of interstitial hyperthermia on normal rat brain

Abstract

Histological changes in the brains of Fischer rats at different times after interstitial heating with various thermal doses were studied. The brains, subjected to sham-heating, and heating at 39 and 40 degrees C for 30 min showed mild capillary congestion and minimal vacuolation at 4, 24 and 72 h. In the brains heated to 41, 42 and 43 degrees C for 30 min, there was local vascular congestion, petechiae, vacuolation and cellular shrinkage with nuclear pyknosis at 4 h; enhanced congestion and petechiae, acute cellular necrosis, infiltration of polymorphonuclear leukocytes and marked vacuolation at the margin at 24h; total coagulative necrosis of all parenchymal and vascular elements, early liquefaction necrosis and vascular hyperplasia at the margin at 72 h; enhanced vascular hyperplasia at the margin at 120 h and 168 h. The threshold thermal dose for the histopathological damage in the rat brain was heating at 41 degrees C for 30 min.

Rapid morphological brain abnormalities during acute methamphetamine intoxication in the rat: An experimental study using light and electron microscopy

“…It is well known that high temperature has destructive effects on various cells (Iwagami, 1996; Willis et al, 2000; Du et al, 2007), especially strong on metabolically active brain cells (Chen et al, 2003; Oifa and Kleshchenov, 1985; Lin et al, 1991; Lin, 1997; Lee et al, 2000), including glial, endothelial and epithelial cells (Bechtold and Brown, 2003; Sharma and Hoopes, 2003). Therefore, robust differences in the amounts of structurally damaged neurons and abnormal GFAP-positive cells as well as a linear correlation between these parameters and NAcc temperature could suggest brain hyperthermia as an important contributor to METH-induced morphological abnormalities.…”

Acute Methamphetamine Intoxication

“…Since brain cells of various subtypes are exceptionally sensitive to high temperature (Bechtold and Brown, 2003; Chen et al, 2003; Oifa and Kleshchenov, 1985; Lee et al, 2000; Lin et al, 1991; Lin, 1997; Sharma and Hoopes, 2003), hyperthermia could be viewed as an important contributor to morphological abnormalities induced by METH. However, this does not mean that high temperature per se is the cause of these changes.…”

Environmental Conditions Modulate Neurotoxic Effects of Psychomotor Stimulant Drugs of Abuse

“…In addition to the known temperature modulation of neural activity, fluctuations in brain temperature could adversely affect brain cells and brain functions. While brain cells seems to well tolerate low temperatures (Arai et al ., 1993; Lucas et al ., 1994), multiple i n vitro studies suggest that high temperature (>40.0°C) has destructive effects on various cells (Iwagami, 1996; Willis et al ., 2000), especially prominent in metabolically active brain cells (Chen et al ., 2003; Lee et al ., 2000; Li et al ., 2004; Lin et al ., 1991; Oifa and Kleshchenov, 1985), including neuronal, glial, endothelial and epithelial cells (Bechtold and Brown, 2003; Sharma and Hoopes, 2003). Rapid damage to brain cells has been also documented in vivo during extreme environmental warming (Cervos-Navarro et al ., 1998; Lin et al ., 1997; Sharma et al ., 1992) and acute METH intoxication (Kiyatkin et al ., 2007; Sharma and Kiyatkin, 2009), which both result in robust brain hyperthermia as well as increased permeability of the blood-brain barrier (BBB) and vasogenic edema.…”