scholarly journals The effect of age and sex on the expression of GABA signaling components in the human hippocampus and entorhinal cortex

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jayarjun Ethiraj ◽  
Thulani Hansika Palpagama ◽  
Clinton Turner ◽  
Bert van der Werf ◽  
Henry John Waldvogel ◽  
...  

AbstractGamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the nervous system. The GABA signaling system in the brain is comprised of GABA synthesizing enzymes, transporters, GABAA and GABAB receptors (GABAAR and GABABR). Alterations in the expression of these signaling components have been observed in several brain regions throughout aging and between sexes in various animal models. The hippocampus is the memory centre of the brain and is impaired in several age-related disorders. It is composed of two main regions: the Cornu Ammonis (CA1-4) and the Dentate Gyrus (DG), which are interconnected with the Entorhinal Cortex (ECx). The age- and sex-specific changes of GABA signaling components in these regions of the human brain have not been examined. This study is the first to determine the effect of age and sex on the expression of GABA signaling components-GABAAR α1,2,3,5, β1-3, γ2, GABABR R1 and R2 subunits and the GABA synthesizing enzymes GAD 65/67-in the ECx, and the CA1 and DG regions of the human hippocampus using Western blotting. No significant differences were found in GABAAR α1,2,3,5, β1-3, γ2, GABABR R1 and R2 subunit and GAD65/76 expression levels in the ECx, CA1 and DG regions between the younger and older age groups for both sexes. However, we observed a significant negative correlation between age and GABAAR α1subunit level in the CA1 region for females; significant negative correlation between age and GABAAR β1, β3 and γ2 subunit expression in the DG region for males. In females a significant positive correlation was found between age and GABAAR γ2 subunit expression in the ECx and GABABR R2 subunit expression in the CA1 region. The results indicate that age and sex do not affect the expression of GAD 65/67. In conclusion, our results show age- and sex-related GABAA/BR subunit alterations in the ECx and hippocampus that might significantly influence GABAergic neurotransmission and underlie disease susceptibility and progression.

Author(s):  
Rabar M. Abdulrahman ◽  
Balen Muhsin Abdul Rahman

This retrospective study aimed to determine the levels of 25- hydroxyvitamin D [25-(OH) D] in the individuals that have been referred to two laboratories (Bio Lab and King Lab) and to around 50 private side laboratories that use both Bio Lab and King Lab as a referral lab for their tests, in Erbil city, Iraq. Then show the range of deficiency and its relation with sunlight exposure, sex and age. Out of the total number of cases (N=10823), large percentage (nearly 78%) referred to both clinical laboratory based in Erbil city were found to have a deficiency in vitamin D levels, which means they had 25-(OH) D levels lower than 20 μg/L. This study found the percentage of vitamin D level in the serum of groups insufficient, deficient, adequate, optimal; intoxication were 52.8, 24.1, 11, 12 and 0.2% respectively. When the records have been compared according to gender, the results suggested that there was no difference between male and female within the study population (P>0.05), while there was difference in the grouped ages (P<0.05). Our results indicate that although Erbil is located in a Mediterranean country, people living there should periodically check their 25-(OH) D levels, in order to get appropriate supplements of vitamin D, which eventually prevents secondary chronic disease due to vitamin D deficiency.


2012 ◽  
Vol 103 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Berrak Yetimler ◽  
Gökhan Ulusoy ◽  
Turgay Çelik ◽  
Ewa Jakubowska-Doğru

2005 ◽  
Vol 25 (12) ◽  
pp. 1586-1595 ◽  
Author(s):  
Olof Bendel ◽  
Tjerk Bueters ◽  
Mia von Euler ◽  
Sven Ove Ögren ◽  
Johan Sandin ◽  
...  

The pyramidal neurons of the hippocampal CA1 region are essential for cognitive functions such as spatial learning and memory, and are selectively destroyed after cerebral ischemia. To analyze whether degenerated CA1 neurons are replaced by new neurons and whether such regeneration is associated with amelioration in learning and memory deficits, we have used a rat global ischemia model that provides an almost complete disappearance (to approximately 3% of control) of CA1 neurons associated with a robust impairment in spatial learning and memory at two weeks after ischemia. We found that transient cerebral ischemia can evoke a massive formation of new neurons in the CA1 region, reaching approximately 40% of the original number of neurons at 90 days after ischemia (DAI). Co-localization of the mature neuronal marker neuronal nuclei with 5-bromo-2'-deoxyuridine in CA1 confirmed that neurogenesis indeed had occurred after the ischemic insult. Furthermore, we found increased numbers of cells expressing the immature neuron marker polysialic acid neuronal cell adhesion molecule in the adjacent lateral periventricular region, suggesting that the newly formed neurons derive from this region. The reappearance of CA1 neurons was associated with a recovery of ischemia-induced impairments in spatial learning and memory at 90 DAI, suggesting that the newly formed CA1 neurons restore hippocampal CA1 function. In conclusion, these results show that the brain has an endogenous capacity to form new nerve cells after injury, which correlates with a restoration of cognitive functions of the brain.


BMJ ◽  
1971 ◽  
Vol 3 (5775) ◽  
pp. 607-609 ◽  
Author(s):  
K. O'Malley ◽  
J. Crooks ◽  
E. Duke ◽  
I. H. Stevenson

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