Quantitative analysis of MAP2 immunoreactivity in human neocortex of three patients surviving after brain ischemia.

Transient global ischemia caused by cardiac arrest results in lesions that involve all brain structures. The aim of this study was to investigate the distribution of MAP2 immunoreactivity in neurons in the brain of patients surviving for various times after an ischemic incident, using confocal laser scanning microscopy. We performed a quantitative analysis of the distribution and density of MAP2-positive structures in human neocortical areas after survival times of 1 week, 3 months, and 1 year after the cardiac arrest. Three important observations were made in the present study: (i) in all human brain areas investigated (motor, temporal, frontal, and visual cortex) a decrease of MAP2 immunoreactivity was found; (ii) in all studied areas the most significant decrease in MAP2 was found in layers II-III, compared with layers V-VII; (iii) the decrease of MAP2 immunoreactivity in layers II-III was related to the duration of the postischemic period. The maximal decrease, by 66.3% (P < .05), in MAP2-positive pyramidal neurons, was observed in layers II-III in the motor cortex after 1 year of survival after cardiac arrest.