Deterministic progenitor behavior and unitary production of neurons in the neocortex.

Radial glial progenitors (RGPs) are responsible for producing nearly all neocortical neurons. To gain insight into the patterns of RGP division and neuron production, we quantitatively analyzed excitatory neuron genesis in the mouse neocortex using Mosaic Analysis with Double Markers, which provides single-cell resolution of progenitor division patterns and potential in vivo. We found that RGPs progress through a coherent program in which their proliferative potential diminishes in a predictable manner. Upon entry into the neurogenic phase, individual RGPs produce ?8-9 neurons distributed in both deep and superficial layers, indicating a unitary output in neuronal production. Removal of OTX1, a transcription factor transiently expressed in RGPs, results in both deep- and superficial-layer neuron loss and a reduction in neuronal unit size. Moreover, ?1/6 of neurogenic RGPs proceed to produce glia. These results suggest that progenitor behavior and histogenesis in the mammalian neocortex conform to a remarkably orderly and deterministic program.

COVID-19 Induced Brief Psychotic Disorder: A Case Report and Review of Literature.

The COVID-19 pandemic has significantly impacted people around the world, with asymptomatic infection to severe diseases and death. There is an increasing incidence of mental health problems in patients diagnosed with COVID-19. There are some studies that discuss possible mechanisms responsible for psychotic disorders due to coronavirus as well as risk factors for developing psychosis in patients infected with the virus. We report the case and a review of the literature in a 29-year-old female with no past psychiatric history who was diagnosed with a brief psychotic disorder following infection with COVID-19.

Chaperonin Abundance Enhances Bacterial Fitness.

The ability of chaperonins to buffer mutations that affect protein folding pathways suggests that their abundance should be evolutionarily advantageous. Here, we investigate the effect of chaperonin overproduction on cellular fitness in Escherichia coli. We demonstrate that chaperonin abundance confers 1) an ability to tolerate higher temperatures, 2) improved cellular fitness, and 3) enhanced folding of metabolic enzymes, which is expected to lead to enhanced energy harvesting potential.