Acidification can directly affect olfaction in marine organisms

ABSTRACT In the past decade, many studies have investigated effects of low pH/high CO2 as a proxy for ocean acidification on olfactory-mediated behaviours marine organisms. The behaviour fish vary from very large to none at all, and most maladaptive observed been attributed changes in acid–base regulation, leading ion distribution over neural membranes, consequently affecting functioning gamma-aminobutyric acid-mediated (GABAergic) neurotransmission. Here, we highlight possible additional mechanism by which might directly affect olfaction invertebrates. We propose that decrease pH can protonation, thereby, 3D conformation charge odorants and/or their receptors olfactory organs aquatic animals. This sometimes enhance signalling, but time affinity is reduced high CO2/low pH; therefore, activity receptor neurons decreases measured using electrophysiology. signal reception would translate into activation bulb neurons, are responsible processing information brain. Over longer exposures days weeks, gene expression cause these become less active, exacerbating problem. A change system leads inappropriate behavioural responses odorants. discuss gaps literature suggest some experimental design order improve our understanding underlying mechanisms associated resolve current controversy field regarding extent fish.