Neuropsychological correlates of early grief in bereaved older adults.

Prolonged grief disorder (PGD) is associated with impairments in cognitive functioning, but the neuropsychological correlates of early grief in older adults are poorly understood. This preliminary study cross-sectionally examined neuropsychological functioning in bereaved adults with high and low grief symptoms and a non-bereaved comparison sample and further explored the relationship between multidomain cognitive measures and grief severity. A total of ninety-three nondemented older adults (high grief: n = 44; low grief: n = 49) within 12 months post-bereavement and non-bereaved comparison participants (n = 43) completed neuropsychological battery including global and multiple domain-specific cognitive functioning. Linear regression models were used to analyze differences in multidomain cognitive measures between the groups and specifically examine the associations between cognitive performance and grief severity in the bereaved, after covariate adjustment, including depressive symptoms. Bereaved older adults with higher grief symptoms performed worse than those with lower symptoms and non-bereaved participants on executive functioning and attention and processing speed measures. In the bereaved, poorer executive functioning, attention and processing speed correlated with higher grief severity. Attention/processing speed-grief severity correlation was seen in those with time since loss ≤ 6 months, but not > 6 months. Intense early grief is characterised by poorer executive functioning, attention, and processing speed, resembling findings in PGD. The putative role of poorer cognitive functioning during early grief on the transition to integrated grief or the development of PGD remains to be elucidated.

PAX6D instructs neural retinal specification from human embryonic stem cell-derived neuroectoderm.

PAX6 is essential for neural retina (NR) and forebrain development but how PAX6 instructs NR versus forebrain specification remains unknown. We found that the paired-less PAX6, PAX6D, is expressed in NR cells during human eye development and along human embryonic stem cell (hESC) specification to retinal cells. hESCs deficient for PAX6D failed to enter NR specification. Induced expression of PAX6D but not PAX6A in a PAX6-null background restored the NR specification capacity. ChIP-Seq, confirmed by functional assays, revealed a set of retinal genes and non-retinal neural genes that are potential targets of PAX6D, including WNT8B. Inhibition of WNTs or knocking down of WNT8B restored the NR specification capacity of neuroepithelia with PAX6D knockout, whereas activation of WNTs blocked NR specification even when PAX6D was induced. Thus, PAX6D specifies neuroepithelia to NR cells via the regulation of WNT8B.

Fast Generation of Functional Subtype Astrocytes from Human Pluripotent Stem Cells.

Differentiation of astrocytes from human pluripotent stem cells (hPSCs) is a tedious and variable process. This hampers the study of hPSC-generated astrocytes in disease processes and drug development. By using CRISPR/Cas9-mediated inducible expression of NFIA or NFIA plus SOX9 in hPSCs, we developed a method to efficiently generate astrocytes in 4-7 weeks. The astrocytic identity of the induced cells was verified by their characteristic molecular and functional properties as well as after transplantation. Furthermore, we developed a strategy to generate region-specific astrocyte subtypes by combining differentiation of regional progenitors and transgenic induction of astrocytes. This simple and efficient method offers a new opportunity to study the fundamental biology of human astrocytes and their roles in disease processes.