PVALB and Alzheimer disease: However, other studies indicated possible alterations to the parvalbumin-ir basket and chandelier cells in the cerebral cortex of AD patients, but as discussed previously (Blazquez-Llorca et al., 2010), the discrepancy between different laboratories regarding the loss or preservation of GABAergic neurons may be explained by differences in tissue processing, the methods of analysis (quantitative versus qualitative studies), and/or the postmortem delay, together with the clinical variability between patients and control tissue.