Monitoring of intra-mitochondrial NADH redox state is a common in-vivo technique in experimental animals and is rare in clinical studies. The combination of NADH monitoring with the Laser Doppler flowmetry for cerebral blood flow monitoring was described in various publications. Until now, very small effort was made to monitor NADH and CBF inside the cortex of experimental animals. The significance of this monitoring is in its application to experimental models of Parkinson’s disease or to clinical monitoring situations in the intensive care unit, when ICP is monitored. Here we compared the responses of the gerbil or rat brain to oxygen deficiency, monitored on the brain surface and in different depths. After the animals were anesthetized, the two common carotid arteries (gerbil) were isolated and prepared for following occlusion. The brain was exposed and two optical probes were located on its surface. Ischemia was induced by occluding the two carotid arteries, and anoxia was preformed by inhalation of pure N2. After recovery, one of the probes was inserted into the cortex (0.5-3mm) and a second ischemia or anoxia was preformed.
The results showed that:
1. It is possible to monitor both CBF and NADH on the brain surface simultaneously with intracortical location.
2. The responses of the brain to ischemia or anoxia was smaller inside the cortex comparing to brain surface.
3. Negative correlation was found between CBF and NADH in both locations and models.
In conclusion, this new model of simultaneously monitoring of CBF and NADH in different cerebral locations can shed light on various pathophysiological situations.