Neuroscience research has been largely focused on neurons, while an equally important cell type, glia, was sidelined until recently. Astrocytes are star-shaped glial cells responsible for a variety of homeostatic processes of the central nervous system in addition to participating in synaptogenesis and neuronal signal transmission. A variety of immunohistochemical markers have been utilized to visualize these cells in the brain including glial fibrillary acidic protein (GFAP), vimentin, and aldehyde dehydrogenase 1 family member L1 (ALDH1L1). The current study makes use of a multiplex immunohistochemistry protocol developed in collaboration with General Electric to stain rhesus monkey brain tissue samples from the lateral prefrontal cortex (LPFC; n=5) and the primary visual cortex (V1; n=4) with a large number of markers, including GFAP, vimentin, and ALDH1L1 as well as neuronal, microglial, and oxidative stress markers. Using algorithms and manual cell classification, we were able to obtain neuronal and astrocytic counts and use these to estimate astrocyte-to-neuron ratios (ANRs) of the individual brain areas and laminae as well as assess the relative intensity of the markers of interest between areas. Among our findings there was higher ANRs in LPFC compared to V1 gray matter as well as in layer 1 compared to layer 2 in both areas studied. There is also a higher density of astrocytes in layer 1 potentially due to the recognized lack of neurons in this layer. We found significantly higher intensities of GFAP across all gray matter layers in V1 compared to LPFC as well as higher intensities for TSPO and Cleaved Caspase-3 in some V1 layers compared to their LPFC counterparts. This higher intensity of V1 reactive astrocyte markers are potentially due to the increased number of neurons these astrocytes need to support as demonstrated by the low ANR seen in V1 when compared to LPFC. In order to further our knowledge of normal astrocyte properties in these brain areas, it is imperative that we confirm our counts with stereologic studies and include oligodendrocyte markers in our multiplex staining protocol in order to better assess glial numbers within our sections. Additionally, morphological studies assessing rhesus monkey astrocytes identified with a variety of markers is important as we have shown that no one marker stains all astrocytes even though most astrocytes express more than one marker at a time.
| Identifer | oai:union.ndltd.org:bu.edu/oai:open.bu.edu:2144/45533 |
| Date | 30 January 2023 |
| Creators | Castro Mendoza, Paola B. |
| Contributors | Luebke, Jennifer, Medalla, Maria |
| Source Sets | Boston University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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