Glucose/oxygen deprivation and reperfusion upregulate SNAREs and complexin in organotypic hippocampal slice cultures

Abstract

Brain ischemia activates Ca(2+)-dependent synaptic vesicle exocytosis. The synaptosomal-associated protein 25 (SNAP-25) and syntaxin proteins, located on presynaptic terminals, are components of the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex and play a key role in regulating exocytosis. Changes in the expression of SNAREs could affect SNARE complex formation, fusion of vesicles with the presynaptic membrane, and release of neurotransmitters through exocytosis. To investigate the relationship of glucose/oxygen deprivation (GOD)/reperfusion-induced neuronal damage and alteration of presynaptic function, we examined the expression of SNAREs and complexin during GOD and reperfusion using organotypic hippocampal slice cultures. Microtubule-associated protein 2 (MAP-2) staining and transmission electron microscopy showed that neuronal damage increased in a time-dependent manner and both types of neuronal death can occur at different times during GOD and reperfusion. The immunoreactivity of SNAREs such as SNAP-25, vesicle-associated membrane protein and syntaxin and complexin increased in pyramidal cell bodies in the CA1 and CA3 areas in a time-dependent manner following reperfusion. Our data suggest that alteration of presynaptic function may play a partial role in delayed neuronal death during GOD and reperfusion in organotypic hippocampal slice cultures.

Ultrastructural investigation of microcalcification and the role of oxygen–glucose deprivation in cultured rat hippocampal slices

“…5c). These pathological features are consistent with results previously reported in in vivo and in vitro ischemic conditions (Park et al, 2008;Portera-Cailliau et al, 1997;Ruan et al, 2003;Sheldon et al, 2001).…”

Oxygen/Glucose Deprivation and Reperfusion Cause Modifications of Postsynaptic Morphology and Activity in the CA3 Area of Organotypic Hippocampal Slice Cultures

“…Changes in synaptic responses after variable periods of hypoxia or ischemia have also been demonstrated frequently both in vitro [31,43,48,49] and in vivo [50-52]. In this study, OGD/reperfusion induced modifications as shown by EPTA staining for PSD in the CA3 area.…”

“…However, various biochemical and pathological activities, followed by neuronal cell death, can also be detected in the CA3 area along mossy fibers [41,42]. According to our previous studies [31,43], neuronal damage expressed with propidium iodide staining was found both in the CA1 area and CA3 area of hippocampal slice cultures following OGD/reperfusion.…”

Palmitoylethanolamide Ameliorates Hippocampal Damage and Behavioral Dysfunction After Perinatal Asphyxia in the Immature Rat Brain

“…Previous studies have shown that neurofilaments change their degree of phosphorylation after cerebral hypoxia-ischemia (Mink and Johnston, 2000 ) and serve as clinical biomarkers of hypoxic-ischemic encephalopathy (Douglas-Escobar et al, 2010 ). Dendritic alterations are also a common finding under glucose/oxygen deprivation (Park et al, 2008 ) and hypoxic-ischemic injury (Zhu et al, 2003 ; Takita et al, 2004 ). A 40% decrease of MAP-2-positive cells/mm 3 was observed in organotypic hippocampal cultures from asphyxia-exposed animals (Morales et al, 2007 ).…”