Increase in SNAP-25 immunoreactivity in the mossy fibers following transient forebrain ischemia in the gerbil.
SNAP-25 (a synaptosomal-associated protein of 25 kDa) has been shown to be involved both in synaptic vesicle exocytosis and in axonal outgrowth. In the present study, we investigated the changes in SNAP-25 immunoreactivity in the hippocampus of the Mongolian gerbil (Meriones unguiculatus) at different time points after transient forebrain ischemia insult. In parallel, immunostaining for GAP-43, a protein involved in axonal outgrowth, and for syntaxin-1 (stx1A and stx1B), another protein implicated in neurotransmitter release, was also analyzed. The animals were subjected to 2.5 or 5 min of transient forebrain ischemia through bilateral common carotid occlusion, and examined at different intervals after ischemia. SNAP-25 immunoreactivity was increased in the mossy fiber layer as early as 2 days after 5 min of ischemia. Increased SNAP-25 immunoreactivity in mossy fibers was also detected at days 4 and 7 after ischemia. On day 15, SNAP-25 staining was similar to that observed in control non-ischemic animals. In contrast, no changes in GAP-43 and syntaxin-1 immunoreactivity were observed in the mossy fiber layer following 5 min of ischemia. No modifications in SNAP-25, syntaxin-1 or GAP-43 immunoreactivity were observed following 2.5 min of ischemia, the longest period for which no neuronal damage is observed. These results provide evidence of a specific involvement of SNAP-25 in the reactive changes associated with transient forebrain ischemia.
Martí
E
E
Departament de Biologia Cellular i Anatomia Patològica, Universitat de Barcelona, Spain.
Ferrer
I
I
Ballabriga
J
J
Blasi
J
J
D000818:Animals; D016923:Cell Death / Q000502:physiology; D005260:Female; D019922:GAP-43 Protein / Q000032:analysis / Q000276:immunology; D005849:Gerbillinae; D002546:Ischemic Attack, Transient / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008565:Membrane Proteins / Q000032:analysis / Q000276:immunology; D019599:Mossy Fibers, Hippocampal / Q000737:chemistry* / Q000378:metabolism* / Q000473:pathology; D009419:Nerve Tissue Proteins / Q000032:analysis* / Q000276:immunology; D016548:Prosencephalon / Q000098:blood supply* / Q000473:pathology; D050765:Qa-SNARE Proteins; D050825:Synaptosomal-Associated Protein 25
D019922:GAP-43 Protein; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D050765:Qa-SNARE Proteins; D050825:Synaptosomal-Associated Protein 25