| First Author | Wada N | Year | 2014 |
| Journal | Proc Natl Acad Sci U S A | Volume | 111 |
| Issue | 14 | Pages | 5373-8 |
| PubMed ID | 24706878 | Mgi Jnum | J:208617 |
| Mgi Id | MGI:5563836 | Doi | 10.1073/pnas.1402546111 |
| Citation | Wada N, et al. (2014) Role of granule-cell transmission in memory trace of cerebellum-dependent optokinetic motor learning. Proc Natl Acad Sci U S A 111(14):5373-8 |
| abstractText | Adaptation of the optokinetic response (OKR) is an eye movement enhanced by repeated motion of a surrounding visual field and represents a prototype of cerebellum-dependent motor learning. Purkinje cells and vestibular nuclei (VN) receive optokinetic and retinal slip signals via the mossy fiber-granule cell pathway and climbing-fiber projections, respectively. To explore the neural circuits and mechanisms responsible for OKR adaptation, we adopted the reversible neurotransmission-blocking (RNB) technique, in which granule-cell transmission to Purkinje cells was selectively and reversibly blocked by doxycycline-dependent expression of transmission-blocking tetanus toxin in granule cells. Blockade of granule-cell inputs abolished both short-term and long-term OKR adaptation induced by repeated OKR training, but normal levels of both responses were immediately evoked in the pretrained RNB mice by OKR retraining once granule-cell transmission had recovered. Importantly, eye movement elicited by electrical stimulation of the cerebellar focculus was elevated by long-term but not by short-term OKR training in adaptive OKR-negative RNB mice. Furthermore, when the flocculus of adaptive OKR-negative RNB mice was electrically excited in-phase with OKR stimulation, these mice exhibited long-term adaptive OKR. These results indicate that convergent information to the VN was critical for acquisition and storage of long-term OKR adaptation with conjunctive action of Purkinje cells for OKR expression. Interestingly, in contrast to conditioned eyeblink memory, the expression of once acquired adaptive long-term OKR was not abrogated by blockade of granule-cell transmission, suggesting that distinct forms of neural plasticity would operate in different forms of cerebellum-dependent motor learning. |
