Pm. Robison et al., DECREASE IN AMYLOID PRECURSOR PROTEIN PRECEDES HIPPOCAMPAL DEGENERATION IN RAT-BRAIN FOLLOWING TRANSIENT GLOBAL-ISCHEMIA, Brain research, 608(2), 1993, pp. 334-337
We have studied amyloid precursor protein (APP) expression in rat brai
n following transient global ischemia. Ischemic damage 24 h after 30 m
in of four-vessel occlusion (4VO) was limited to the caudate nucleus;
hippocampal pyramidal neurons appeared histologically normal by light
microscopy. Consistent with ongoing neurodegeneration in the caudate n
ucleus, microtubule-associated protein-2 (MAP-2) levels assessed by im
munoblots were significantly reduced in homogenates of caudate nucleus
after 4VO. MAP-2 levels In the hippocampus were comparable to control
values. In contrast, full length APP levels in both the caudate nucle
us and hippocampal homogenates were significantly decreased following
4VO despite normal hippocampal morphology at 24 h. These findings sugg
est that decrements in full length APP precede overt neuronal damage a
nd may play a role in the subsequent delayed neurodegeneration in the
hippocampus.