RT Journal Article SR Electronic T1 GABAA receptors activate fish feeding behaviour via two distinct functional pathways JF The Journal of Experimental Biology JO J. Exp. Biol. FD The Company of Biologists Ltd SP jeb170514 DO 10.1242/jeb.170514 VO 221 IS 3 A1 Snigirov, Sergey A1 Sylantyev, Sergiy YR 2018 UL http://jeb.biologists.org/content/221/3/jeb170514.abstract AB Benzodiazepines, acting through ionotropic receptors of γ-aminobutyric acid (GABAA receptors, GABAR), have been shown to modify feeding behaviour and increase appetite in humans and non-human subjects. However, the cellular and molecular mechanisms that underlie connected short-term behavioural fluctuations are still unclear. In the present study, we used Carassius gibelio (Prussian carp) as a model organism to research the impact of scantily explored benzodiazepine phenazepam (PNZ) on feeding behaviour and the related molecular mechanisms of PNZ action at single-cell and single-receptor levels. We found that the feeding activity of C. gibelio is under control of GABARs via two distinct mechanisms: orthosteric (triggered by GABA binding site) and allosteric (triggered by benzodiazepine binding site). PNZ displayed clear stimulatory effects on both mechanisms in a GABA-dependent manner. In addition, orthosteric and allosteric effects were found to be partially competitive, which leads to complex behavioural repercussions of conjoint effects of GABAR ligands.