Cerebellar Control of Reach Kinematics for Endpoint Precision

Abstract

Highlights d Cerebellar anterior interposed nucleus (IntA) neurons are modulated near reach endpoint d Closed-loop optogenetic manipulation of IntA adjusts reach kinematics in real time d IntA activity is variably engaged to enhance reach endpoint precision d Data provide a mechanistic insight into reach dysmetria

Quantification of Mouse Reach Kinematics as a Foundation for Mechanistic Interrogation of Motor Control

“…Previous studies, as well as the data presented here, highlight the decelerative phase of reaching movements as particularly important for adjusting to initial variability in reach kinematics, a process that is under direct neural control (Becker & Person, 2019;K. Novak et al, 2002).…”

“…On the contrary, we argue that late-phase velocity asymmetries represent an adaptive response to the increased kinematic variability of distant (and hence faster) reaches. In our view, the inherent tradeoff between speed and accuracy could be mitigated by a shared neural mechanism of online kinematic control that adjusts for initial variability in service of endpoint precision (Becker & Person, 2019;J Messier & Kalaska, 1999). Without this neural mechanism intact, we predict a decrease in reach precision, potentially resembling the oscillatory dysmetria of cerebellar patients (Diener & Dichgans, 1992;Hore et al, 1991).…”

“…Paw position was monitored by an infrared-based real-time motion-capture system described previously (Becker & Person, 2019). Briefly, five 120 frames-per-second cameras (Optitrack Slim3U; Corvallis, OR), each with a 10 mm focal length lens (Edmund Optics, Barrington, NJ) and infrared LED light ring array, were fixed in place with custom built mounts and focused onto a capture volume of approximately 4 cm 3 , large enough to capture the entirety of a mouse reaching movement.…”

NINscope: a versatile miniscope for multi-region circuit investigations

“…In line with findings of tightly coordinated activity in cortex and subcortical structures, recent work has highlighted the motor cortex as an input-driven dynamical system (Sauerbrei et al 2018) , where thalamic input is a prerequisite to drive movements as they happen. Cerebellar output appears essential not only for contributing to the precision of ongoing movements (Becker and Person 2019) , but also their planning in sensory discrimination tasks (Gao et al 2018;Chabrol, Blot, and Mrsic-Flogel 2019) . Thus, despite redundancy of motor systems as seen when lesioning selective regions -and assessment of motor performance after a recovery period-, both cortical and subcortical regions are required for successful motor planning and performance under natural conditions.…”

Monosynaptic Inputs to Excitatory and Inhibitory Neurons of the Intermediate and Deep Layers of the Superior Colliculus

“…3) and are likely important for localizing potential targets in space, while the SNr sends a robust inhibitory projection (Graybiel and Ragsdale, 1979), which likely conveys the necessary values associated with individual targets that are required to select among them (Handel and Glimcher, 2000;Basso and Wurtz, 2002;Sato and Hikosaka, 2002;Bryden et al, 2011). Additionally, cerebellar projections to the SCid may be critical in conveying predictive information regarding the position of effectors throughout the trajectory of the movement (Ohyama et al, 2003;Shadmehr, 2017;Owens et al, 2018;Becker and Person, 2019), ultimately mediating successful target acquisition. Indeed, studies performing muscimol inactivation of the cFN in monkeys making saccades to visual targets concluded that cerebellotectal projections might provide the SCid with information about the displacement needed to acquire spatial targets (Goffart et al, 1998).…”