A disinhibitory mechanism biases Drosophila innate light preference.

Nature communications (2019-01-12)
Weiqiao Zhao, Peipei Zhou, Caixia Gong, Zhenhuan Ouyang, Jie Wang, Nenggan Zheng, Zhefeng Gong
ABSTRACT

Innate preference toward environmental conditions is crucial for animal survival. Although much is known about the neural processing of sensory information, how the aversive or attractive sensory stimulus is transformed through central brain neurons into avoidance or approaching behavior is largely unclear. Here we show that Drosophila larval light preference behavior is regulated by a disinhibitory mechanism. In the disinhibitory circuit, a pair of GABAergic neurons exerts tonic inhibition on one pair of contralateral projecting neurons that control larval reorientation behavior. When a larva enters the light area, the reorientation-controlling neurons are disinhibited to allow reorientation to occur as the upstream inhibitory neurons are repressed by light. When the larva exits the light area, the inhibition on the downstream neurons is restored to repress further reorientation and thus prevents the larva from re-entering the light area. We suggest that disinhibition may serve as a common neural mechanism for animal innate preference behavior.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Collagenase from Clostridium histolyticum, for general use, Type I, 0.25-1.0 FALGPA units/mg solid, ≥125 CDU/mg solid
Sigma-Aldrich
Protease from Streptomyces griseus, Type XIV, ≥3.5 units/mg solid, powder
Sigma-Aldrich
Anti-GABA antibody produced in rabbit, affinity isolated antibody, buffered aqueous solution
Sigma-Aldrich
γ-Aminobutyric acid, BioXtra, ≥99%