Positive feedback of efferent copy via pontine nucleus facilitates cerebellum-mediated associative learning
Na Xiao,
Guangyan Wu,
Zhanhong Zhou,
Juan Yao,
Bing Wu,
Jianfeng Sui,
Chung Tin
Affiliations
Na Xiao
Department of Biomedical Engineering, City University of Hong Kong, Kowloon Tong, Hong Kong; Advanced Biomedical Instrumentation Centre, Shatin, N.T., Hong Kong; Department of Mechanical Engineering, The University of Hong Kong, Pok Fu Lam, Hong Kong
Guangyan Wu
Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China; Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
Zhanhong Zhou
Department of Biomedical Engineering, City University of Hong Kong, Kowloon Tong, Hong Kong
Juan Yao
Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China; Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
Bing Wu
Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China; Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China
Jianfeng Sui
Experimental Center of Basic Medicine, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China; Department of Physiology, College of Basic Medical Sciences, Army Medical University, Chongqing 400038, China; Corresponding author
Chung Tin
Department of Biomedical Engineering, City University of Hong Kong, Kowloon Tong, Hong Kong; Corresponding author
Summary: The cerebellum is critical for motor coordination and learning. However, the role of feedback circuitry in this brain region has not been fully explored. Here, we characterize a nucleo-ponto-cortical feedback pathway in classical delayed eyeblink conditioning (dEBC) of rats. We find that the efference copy is conveyed from the interposed cerebellar nucleus (Int) to cerebellar cortex through pontine nucleus (PN). Inhibiting or exciting the projection from the Int to the PN can decelerate or speed up acquisition of dEBC, respectively. Importantly, we identify two subpopulations of PN neurons (PN1 and PN2) that convey and integrate the feedback signals with feedforward sensory signals. We also show that the feedforward and feedback pathways via different types of PN neurons contribute to the plastic changes and cooperate synergistically to the learning of dEBC. Our results suggest that this excitatory nucleo-ponto-cortical feedback plays a significant role in modulating associative motor learning in cerebellum.
