PT  - JOURNAL ARTICLE
AU  - Wataru Koyama
AU  - Ryo Hosomi
AU  - Koji Matsuda
AU  - Koichi Kawakami
AU  - Masahiko Hibi
AU  - Takashi Shimizu
TI  - Involvement of Cerebellar Neural Circuits in Active Avoidance Conditioning in Zebrafish
AID  - 10.1523/ENEURO.0507-20.2021
DP  - 2021 May 01
TA  - eneuro
PG  - ENEURO.0507-20.2021
VI  - 8
IP  - 3
4099  - http://www.eneuro.org/content/8/3/ENEURO.0507-20.2021.short
4100  - http://www.eneuro.org/content/8/3/ENEURO.0507-20.2021.full
SO  - eNeuro2021 May 01; 8
AB  - When animals repeatedly receive a combination of neutral conditional stimulus (CS) and aversive unconditional stimulus (US), they learn the relationship between CS and US, and show conditioned fear responses after CS. They show passive responses such as freezing or panic movements (classical or Pavlovian fear conditioning), or active behavioral responses to avoid aversive stimuli (active avoidance). Previous studies suggested the roles of the cerebellum in classical fear conditioning but it remains elusive whether the cerebellum is involved in active avoidance conditioning. In this study, we analyzed the roles of cerebellar neural circuits during active avoidance in adult zebrafish. When pairs of CS (light) and US (electric shock) were administered to wild-type zebrafish, about half of them displayed active avoidance. The expression of botulinum toxin, which inhibits the release of neurotransmitters, in cerebellar granule cells (GCs) or Purkinje cells (PCs) did not affect conditioning-independent swimming behaviors, but did inhibit active avoidance conditioning. Nitroreductase (NTR)-mediated ablation of PCs in adult zebrafish also impaired active avoidance. Furthermore, the inhibited transmission of GCs or PCs resulted in reduced fear-conditioned Pavlovian fear responses. Our findings suggest that the zebrafish cerebellum plays an active role in active avoidance conditioning.