2020/03/25 by Sang‐Yoon Kim, Kim, Sang-Yoon, Woochang Lim +1
Biochemistry, Genetics and Molecular Biology · Neuroscience · #Biological Physics (physics.bio-ph) #FOS: Biological sciences #FOS: Physical sciences #Neural dynamics and brain function #Neurons and Cognition (q-bio.NC) #Photoreceptor and optogenetics research #Retinal Development and Disorders
paper · pdf · doi:10.48550/arxiv.2003.11325
openalex publication_date 2020/03/25 · openalex created_date 2020/04/03 · openalex updated_date 2026/07/28
We consider a cerebellar ring network for the optokinetic response (OKR), and investigate the effect of diverse recoding of granule (GR) cells on OKR by varying the connection probability pc from Golgi to GR cells. For an optimal value of pc^*~(=0.06), individual GR cells exhibit diverse spiking patterns which are in-phase, anti-phase, or complex out-of-phase with respect to their population-averaged firing activity. Then, these diversely-recoded signals via parallel fibers (PFs) from GR cells are effectively depressed by the error-teaching signals via climbing fibers from the inferior olive which are also in-phase ones. Synaptic weights at in-phase PF-Purkinje cell (PC) synapses of active GR cells are strongly depressed via strong long-term depression (LTD), while those at anti-phase and complex out-of-phase PF-PC synapses are weakly depressed through weak LTD. This kind of "effective" depression (i.e., strong/weak LTD) at the PF-PC synapses causes a big modulation in firings of PCs, which then exert effective inhibitory coordination on the vestibular nucleus (VN) neuron (which evokes OKR). For the firing of the VN neuron, the learning gain degree \calLg, corresponding to the modulation gain ratio, increases with increasing the learning cycle, and it saturates at about the 300th cycle. By varying pc from pc^*, we find that a plot of saturated learning gain degree \cal Lg^* versus pc forms a bell-shaped curve with a peak at pc^* (where the diversity degree in spiking patterns of GR cells is also maximum). Consequently, the more diverse in recoding of GR cells, the more effective in motor learning for the OKR adaptation.