Spatial and temporal distribution of pituitary adenylate cyclase activating polypeptide in gerbil global cerebral ischemia

In the present study, we used immunohistochemistry to investigate the effec ts of transient global ischemia on pituitary adenylate cyclase activating p olypeptide (PACAP) immunoreactivity in gerbil brain regions. PACAP immunore activity had significantly decreased in the pyramidal cells of CA1 subfield susceptible to ischemic insult at 1-4 days after transient global ischemia . On the contrary, PACAP immunoreactivity had not changed in the pyramidal cell bodies of more resistant CA3 subfield after ischemic injury. In the Pu rkinje cell layer, PACAP immunoreactivity had significantly decreased I day following transient ischemia, and had increased 2 days after ischemia. The first demonstration of the postischemic localizations of PACAP should allo w us to gain a more fundamental rationale for developing methods of treatin g ischemic brain damage with neuroprotective peptides such as PACAP. (C) 20 01 Elsevier Science Ireland Ltd. All rights reserved.