We performed live imaging of the nuclear shape of the upper layer neurons of the visual cortex in young and aged NexCre;SUN1-GFP mice in vivo with two-photon microscopy before, during, and after visual light exposure following the prior preparations of craniotomy on the visual cortex for time-lapse imaging. NexCre;SUN1-GFP mice expressed the GFP-fused SUN1 protein, a protein on the outer nuclear membrane, in the excitatory neurons under the control of the NeuroD6/Nex gene locus.
Keywords; time-lapse imaging, two-photon microscopy, nucleus, excitatory neuron, visual cortex, visual stimulation, aging.
See detail in Frey et al., bioRxiv, 2022
Tanita Frey, Tomonari Murakami, Koichiro Maki, Takumi Kawaue, Ayaka Sugai, Naotaka Nakazawa, Taiji Adachi, Mineko Kengaku, Kenichi Ohki, Yukiko Gotoh, Yusuke Kishi (2022/01/01), Age-associated reduction of nuclear shape dynamics in excitatory neurons of the visual cortex, 2022.08.22.504704
Published in 2022/01/01
(Abstract) Neurons decline in their functionality over time, and age-related neuronal alterations are associated with phenotypes of neurodegenerative diseases. In non-neural tissues, an infolded nuclear shape has been proposed as a hallmark of aged cells and neurons with infolded nuclei have also been reported to be associated with neuronal activity. Here, we perform time-lapse imaging in the visual cortex of Nex-Cre;SUN1-GFP mice. Nuclear infolding was observed within 15 minutes of stimulation in young nuclei, while the aged nuclei were already infolded pre-stimulation and showed reduced dynamics of the morphology. In young nuclei, the depletion of the stimuli restored the nucleus to a spherical shape and reduced the dynamic behavior, suggesting that nuclear infolding is a reversible process. We also found the aged nucleus to be stiffer than the young one, further relating to the age-associated loss of nuclear shape dynamics. We reveal temporal changes in the nuclear shape upon external stimulation and observe that these morphological dynamics decrease with age.Competing Interest StatementThe authors have declared no competing interest.