GABAA receptor subunit expression changes in the human Alzheimer's disease hippocampus, subiculum, entorhinal cortex and superior temporal gyrus. Issue 5 (June 2018)

• Record Type: Journal Article
• Authors: Kwakowsky, Andrea; Calvo‐Flores Guzmán, Beatriz; Pandya, Madhavi; Turner, Clinton; Waldvogel, Henry J.; Faull, Richard L.
• Is Part Of: Journal of neurochemistry. Volume 145:Issue 5(2018)
• Page Start: 374
• Page End: 392
• Publication Date: 2018-06
• Subjects: Alzheimer's disease -- entorhinal cortex -- GABAA receptor -- hippocampus -- subiculum -- superior temporal gyrus; Neurochemistry -- Periodicals; 616.8042
• DOI: 10.1111/jnc.14325
• Languages: English
• ISSNs: 0022-3042

Abstract

Abstract: Gamma‐aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the central nervous system. GABA type A receptors (GABAA Rs) are severely affected in Alzheimer's disease (AD). However, the distribution and subunit composition of GABAA Rs in the AD brain are not well understood. This is the first comprehensive study to show brain region‐ and cell layer‐specific alterations in the expression of the GABAA R subunits α1‐3, α5, β1‐3 and γ2 in the human AD hippocampus, entorhinal cortex and superior temporal gyrus. In late‐stage AD tissue samples using immunohistochemistry we found significant alteration of all investigated GABAA Rs subunits except for α3 and β1 that were well preserved. The most prominent changes include an increase in GABAA R α1 expression associated with AD in all layers of the CA3 region, in the stratum (str.) granulare and hilus of the dentate gyrus. We found a significant increase in GABAA R α2 expression in the str. oriens of the CA1‐3, str. radiatum of the CA2, 3 and decrease in the str. pyramidale of the CA1 region in AD cases. In AD there was a significant increase in GABAA R α5 subunit expression in str. pyramidale, str. oriens of the CA1 region and decrease in the superior temporal gyrus. We also found a significant decrease in the GABAA R β3 subunit immunoreactivity in the str. oriens of the CA2, str. granulare and str. moleculare of the dentate gyrus. In conclusion, these findings indicate that the expression of the GABAA R subunits shows brain region‐ and layer‐specific alterations in AD, and these changes could significantly influence and alter GABAA R function in the disease. Cover Image for this issue: doi:10.1111/jnc.14179 . Abstract : GABAA R subunit density changes in the human Alzheimer's disease hippocampus, subiculum and entorhinal cortex. A schematic diagram of the human hippocampal formation and related structures and the region‐ and cell layer‐specific alterations in the expression of the GABAA R subunits α1‐2, α5, β2, 3 and γ2 in Alzheimer's disease (AD). In late‐stage AD tissue samples using immunohistochemistry we found significant alterations all of these GABAA Rs subunits while the α3 and β1 subunits were well preserved. increase or decrease in GABAA R subunit density in AD cases compared to controls. Cover Image for this issue: doi:10.1111/jnc.14179 .