Differential expression of synaptosome-associated protein 25 kDa [SNAP-25] in hippocampi of neonatal mice following exposure to human influenza virus in utero.
We investigated the role of maternal exposure to human influenza virus [HI] in C57BL/6 mice on day 9 of pregnancy on the hippocampal expression of SNAP-25 in postnatal day 0 neonates, and compared them to sham-infected pups. The expression of SNAP-25 in infected neonates varied along the septotemporal axis of hippocampus and in various anatomic layers. Quantitative densitometric analysis of specific immunogold silver-enhanced SNAP-25 immunoreactivity [IR] showed increases of 40-347% over control in all septal-dorsal hippocampal layers except for the subplate layer. In mid septo-temporal hippocampus, SNAP-25 IR increased by 10-114% over control in all layers, except for the hippocampal plate, but the extent of this increase was smaller than in the dorsal-septal area. Finally,in temporal-ventral levels, SNAP-25 expression was reduced in all infected layers by 21-33% below control except for mild increases of 8.8 and 10% in subplate and hippocampal plate layers. Additionally, the infected SNAP-25 maximal density bin shifted to lower values dorsally and to higher values medially, with ventral maximal bins remaining unchanged when compared to controls. The differential expression of SNAP-25 in the hippocampi of infected neonates indicates a variable degree of vulnerability across the septo-temporal axis of hippocampus. It is surmised that while viral infection may induce excitotoxicity in the ventral hippocampus, it may cause reactive synapto-genesis in the medial and dorsal sectors of the developing brains of postnatal day 0 neonates.
Fatemi
S H
SH
Department of Cell Biology and Neuroanatomy, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
Sidwell
R
R
Kist
D
D
Akhter
P
P
Meltzer
H Y
HY
Bailey
K
K
Thuras
P
P
Sedgwick
J
J
D000818:Animals; D000831:Animals, Newborn; D005260:Female; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology / Q000821:virology; D006801:Humans; D009980:Influenza A virus; D007251:Influenza, Human / Q000196:embryology / Q000378:metabolism*; D008565:Membrane Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D009419:Nerve Tissue Proteins / Q000096:biosynthesis*; D009928:Organ Specificity; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D050825:Synaptosomal-Associated Protein 25
D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C494208:SNAP25 protein, human; C494209:Snap25 protein, mouse; D050825:Synaptosomal-Associated Protein 25