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Publication Spotlight: Blumberg Lab

Congratulations to Dooley et al and the Blumberg Lab at at the University of Iowa, who recently published a paper in Current Biology, entitled “Movements during sleep reveal the developmental emergence of a cerebellar-dependent internal model in motor thalamus“. DOI: https://doi.org/10.1016/j.cub.2021.10.014

Significance:

Without looking, we can mentally picture where our limb is located in space, moment-to-moment. This is possible because the brain forms computational representations of movements in real-time (while the movement occurs). Movements are then precisely coordinated with sensory feedback. But when do these internal models develop? And what conditions are required to ensure development?

Model and Methodology:

Post-natal rats perform spontaneous limb movements (aka myoclonic twitches) during sleep. These twitches are linked to sensorimotor development and can provide information on the timing between motor commands and sensory feedback. Previous research shows that internal models of movement are generated in the cerebellum in adults. Dooley et al recorded ephys in the cerebellothalamic system of post-natal rats at different ages to assess neural activity caused by twitches during sleep.

What TDT equipment was used?

The Lab Rat! TDT has an inexpensive, compact ephys system for recording up to 32-channels of single-unit activity. Here, Dooley et al recorded up to 32-ch of single unit activity from the somatosensory and motor thalamus and primary motor cortex as well as 2-ch of nuchal and bicep EMG for twitch activity.

Main Findings:

By P20, the neural activity in the ventral lateral (VL) thalamic nuclei shifted to the same time as the twitch (and no longer lagged behind). This is particularly interesting as the VL receives both somatosensory and cerebellar inputs – while the ventral posterior (VP) thalamic nuclei only receives somatosensory input. The continued lag in neural activity at P20 in the VP would be expected as the VP only receives sensory inputs. When the deep cerebellar nuclei (DCN) was pharmacologically inactivated, the lag in neural activity in the VL at P20 re-emerged. This finding suggests that the VL is critical to the development of internal models of movement and that this neural activity is cerebellar dependent.

Research Focus of the Lab:

The Blumberg lab studies sleep during neural development and the impacts of sleep on neural control and function – i.e. “why [do] we sleep so much more when we are young, and what can go wrong when we don’t.” Dooley is particularly interested in the development of the sensorimotor system and progression of self-generated movements.

Also, Dooley gave a talk on his work last year. Be sure to check it out! 👇🏻

Written by Jessica Falcone, PhD