Neuroscience 2004 Abstract
| Presentation Number: | 99.9 |
|---|---|
| Abstract Title: | AMPA receptor subunit expression in the fetal human brain at midgestation. |
| Authors: |
Talos, D. M.*1
; Follett, P. L.1
; Levada, R. E.1
; Volpe, J. J.1
; Jensen, F. E.1
1Neurol., Children's Hosp./Harvard Med. Sch., Boston, MA |
| Primary Theme and Topics |
Neurological and Psychiatric Conditions - Ischemia -- Excitotoxicity and cell death |
| Secondary Theme and Topics | Development<br />- Neurogenesis and Gliogenesis<br />-- Neuron-glia interactions |
| Session: |
99. Ischemia: Excitotoxicity and Cell Death I Poster |
| Presentation Time: | Saturday, October 23, 2004 1:00 PM-2:00 PM |
| Location: | San Diego Convention Center - Hall A-H, Board # RR6 |
| Keywords: | GLUTAMATE RECEPTOR, DEVELOPMENT, HYPOXIA, EXCITOTOXICITY |
Patterns of brain injury due to hypoxia/ischemia (H/I) are age dependent: the preterm brain more vulnerable to white matter (WM) injury and the term infant more vulnerable to cortical neuronal injury and seizures. Animal models indicate that excitotoxicity due to overexpression of Ca2+ permeable AMPA receptors (AMPARs) may underlay this age-dependent regional vulnerability. Our previous studies in developing human brain suggest that Ca2+ permeable AMPARs are overexpressed on WM oligodendrocytes during the window of enhanced susceptibility to H/I (Follett et al., J Neurosci; 2004), and on cortical neurons when H/I causes cortical infarctions and seizures (Talos et al., SFN Abs; 2003). We hypothesized that AMPAR expression may regulate H/I injury patterns during earlier fetal development, specifically on critical transient cell types such as radial glia and subplate neurons. We evaluated whether Ca2+ permeable AMPARs were expressed on these cells at midgestation. Western blot analysis and immunocytochemistry (ICC) were performed on 12 normal human parietal lobe autopsy samples (17-23 gestational weeks). Relative to adult, GluR1 (mean 240%) and GluR4 (mean 460%) levels were elevated, while GluR2 expression was low (mean 57%). ICC was performed using GluR1, GluR2 and GluR4 antibodies, in combination with neuronal and glial markers. Subplate neurons, located below the developing cortex, showed intense GluR1 labeling on both cell bodies and processes, in contrast to weak, scattered GluR2 and GluR4 staining. Numerous radial glial fibers stained with GFAP and vimentin were present in all cortical areas and showed robust GluR4 immunoreactivity, but no GluR1 or GluR2 labeling. These data indicate that at midgestation, subplate neurons and radial glia possess AMPAR subunits consistent with Ca2+ permeability, suggesting potential selective vulnerability to fetal hypoxic/ischemic injury.
Supported by W. R. Hearst Fdn, Ch. H. Hood Fdn, NIH HD01359, NS38475, and NS31718.
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2004 Neuroscience Meeting Planner. San Diego, CA: Society for Neuroscience, 2004. Online.
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