Physiological basis linking sleep continuity and age-related cognitive deficits: in vivo manipulation and monitoring of activity of layer 5 neurons in the cortex of mice

A good night’s sleep is essential to maintain proper mental health. In particular, consolidated periods of sleep (i.e. sleep continuity) seem to be critical for cognition as reported in humans (Della Monica et al., 2018) and rodents (Rolls et al., 2011). Furthermore, the deterioration of sleep continuity with age suggests an important, yet poorly explored, relationship between both phenomena.

The project will investigate this question by assessing the role of a specific type of brain cells located in layer 5 (L5) of the cortex which has been implicated in both cognition (Ramaswamy and Markram, 2015) and sleep regulation (Krone et al., 2021; Seibt et al., 2017).

The PhD candidate will use a combination of state-of-the-art in vivo calcium imaging (photometry), wireless EEG, chemogenetics, and behavioural techniques in freely behaving animals to determine whether the activity of L5 cortical cells are causally linked to sleep fragmentation and cognitive decline during ageing.

The project will be conducted at the University of Surrey, under the supervision of Dr Julie Seibt and Prof Derk-Jan Dijk, within the Sleep Research Centre. Applicants must be highly motivated and have some background in neuroscience or related fields, ideally a Master’s degree. A background in EEG recording and analysis, or rodent behaviour is an advantage. This project is part of the Biosciences and Medicine PhD programme.

A First or Upper Second-Class Honours degree from the UK (or equivalent qualification from international Institutions) or Masters degree in a relevant subject area.

English language requirements

IELTS requirements: overall score of 6.5 or above (or equivalent) with 6.0 in each individual category.

Surrey Sleep Research Centre

References

Della Monica, C., Johnsen, S., Atzori, G., Groeger, J.A., Dijk, D.-J., 2018. Rapid Eye Movement Sleep, Sleep Continuity and Slow Wave Sleep as Predictors of Cognition, Mood, and Subjective Sleep Quality in Healthy Men and Women, Aged 20-84 Years. Front. Psychiatry 9, 255. https://doi.org/10.3389/fpsyt.2018.00255

Krone, L.B., Yamagata, T., Blanco-Duque, C., Guillaumin, M.C.C., Kahn, M.C., van der Vinne, V., McKillop, L.E., Tam, S.K.E., Peirson, S.N., Akerman, C.J., Hoerder-Suabedissen, A., Molnár, Z., Vyazovskiy, V.V., 2021. A role for the cortex in sleep-wake regulation. Nat. Neurosci. 24, 1210–1215. https://doi.org/10.1038/s41593-021-00894-6

Ramaswamy, S., Markram, H., 2015. Anatomy and physiology of the thick-tufted layer 5 pyramidal neuron. Front. Cell. Neurosci. 9. https://doi.org/10.3389/fncel.2015.00233

Rolls, A., Colas, D., Adamantidis, A., Carter, M., Lanre-Amos, T., Heller, H.C., de Lecea, L., 2011. Optogenetic disruption of sleep continuity impairs memory consolidation. Proc. Natl. Acad. Sci. U. S. A. 108, 13305–13310. https://doi.org/10.1073/pnas.1015633108

Seibt, J., Richard, C.J., Sigl-Glöckner, J., Takahashi, N., Kaplan, D.I., Doron, G., de Limoges, D., Bocklisch, C., Larkum, M.E., 2017. Cortical dendritic activity correlates with spindle-rich oscillations during sleep in rodents. Nat. Commun. 8, 684. https://doi.org/10.1038/s41467-017-00735-w