TY - JOUR
T1 - Control of brain temperature during experimental global ischemia in rats
AU - Brambrink, Ansgar M.
AU - Kopacz, Laszlo
AU - Astheimer, Andreas
AU - Noga, Holger
AU - Heimann, Axel
AU - Kempski, Oliver
PY - 1999/10/15
Y1 - 1999/10/15
N2 - Temperature control during experimental ischemia continues to be of major interest. However, if exposure of brain tissue is necessary during the experiment, regional heat loss may occur even when the core temperature is maintained. Furthermore, valid non-invasive brain temperature monitoring is difficult in small rodents. This paper describes a method for both monitoring and maintenance of brain temperature during small animal preparations in a stereotaxic frame. The device used includes an ear-bar thermocouple probe and a small near-infrared radiator. The new equipment permitted to maintain peri- ischemic brain temperature at a desired level while carrying out non-invasive continuous recordings of cerebral blood flow (laser Doppler-flowmetry) and of electrical brain function (EEG). In contrast, without extracranial heat application, superficial and basal brain temperatures decreased during global cerebral ischemia by 4.1±0.1 and 4.6±0.4°C (mean±SEM), respectively, returning to baseline values at 15-30 min of reperfusion while rectal (core) temperature remained stable at baseline values. The ear-bar thermocouple probe (tympanic membrane) reliably reflected basal brain temperature, and temperature in superficial brain areas correlated well with that in the temporal muscle. Our data show that the new system allows to exclude unwanted hypothermic neuroprotection, and does not interfere with optical and electrical measurement techniques.
AB - Temperature control during experimental ischemia continues to be of major interest. However, if exposure of brain tissue is necessary during the experiment, regional heat loss may occur even when the core temperature is maintained. Furthermore, valid non-invasive brain temperature monitoring is difficult in small rodents. This paper describes a method for both monitoring and maintenance of brain temperature during small animal preparations in a stereotaxic frame. The device used includes an ear-bar thermocouple probe and a small near-infrared radiator. The new equipment permitted to maintain peri- ischemic brain temperature at a desired level while carrying out non-invasive continuous recordings of cerebral blood flow (laser Doppler-flowmetry) and of electrical brain function (EEG). In contrast, without extracranial heat application, superficial and basal brain temperatures decreased during global cerebral ischemia by 4.1±0.1 and 4.6±0.4°C (mean±SEM), respectively, returning to baseline values at 15-30 min of reperfusion while rectal (core) temperature remained stable at baseline values. The ear-bar thermocouple probe (tympanic membrane) reliably reflected basal brain temperature, and temperature in superficial brain areas correlated well with that in the temporal muscle. Our data show that the new system allows to exclude unwanted hypothermic neuroprotection, and does not interfere with optical and electrical measurement techniques.
KW - Brain temperature
KW - Ear-bar thermocouple probe
KW - Hypothermia
KW - Ischemia
KW - Near-infrared radiator
KW - Neuroprotection
KW - Rat
KW - Tympanic membrane
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U2 - 10.1016/S0165-0270(99)00100-4
DO - 10.1016/S0165-0270(99)00100-4
M3 - Article
C2 - 10595709
AN - SCOPUS:0032755427
SN - 0165-0270
VL - 92
SP - 111
EP - 122
JO - Journal of Neuroscience Methods
JF - Journal of Neuroscience Methods
IS - 1-2
ER -