Morphofunctional experience-dependent plasticity in the honeybee brain

Abstract

Repeated or prolonged exposure to an odorant without any positive or negative reinforcement produces experience-dependent plasticity, which results in habituation and latent inhibition. In the honeybee (), it has been demonstrated that, even if the absolute neural representation of an odor in the primary olfactory center, the antennal lobe (AL), is not changed by repeated presentations, its relative representation with respect to unfamiliar stimuli is modified. In particular, the representation of a stimulus composed of a 50:50 mixture of a familiar and a novel odorant becomes more similar to that of the novel stimulus after repeated stimulus preexposure. In a calcium-imaging study, we found that the same functional effect develops following prolonged odor exposure. By analyzing the brains of the animals subjected to this procedure, we found that such functional changes are accompanied by morphological changes in the AL (i.e., a decrease in volume in specific glomeruli). The AL glomeruli that exhibited structural plasticity also modified their functional responses to the three stimuli (familiar odor, novel odor, binary mixture). We suggest a model in which rebalancing inhibition within the AL glomeruli may be sufficient to elicit structural and functional correlates of experience-dependent plasticity.

Olfactory coding in honeybees

“…The model comprises two superimposed and glomerulus-specific learning effects: a non-associative effect in presence of a pre-synaptic activity not followed by a coincident post-synaptic one (as in the case of an inhibitory LN-to-OSN synapse), and an associative one that relies on coincident pre- and post-synaptic activity (as in the case of an excitatory OSN-to-PN synapse) in presence of an appetitive reinforcement (here, mediated by the octopaminergic VUMmx1 neuron) (Rath et al 2011 ). The olfactory system is also modulated by developmental plasticity, where exposure to odors during development leads to morphological changes (Andrione et al 2017 ; Devaud et al 2001 ; Hourcade et al 2009 ; Sachse et al 2007 ), or influences their odorant sensitivity and discrimination capability (Jernigan et al 2020 ).…”

Review of emerging concepts in nanotoxicology: opportunities and challenges for safer nanomaterial design

“…Starting with a very complex material, it is very difficult to determine whether the component of that matrix or the complexity is causing the effect. There have been a lot of pristine studies exposing animals and cells in vivo or in vitro but those experimental setups are not realistic concerning real exposure where the concentration and physiochemical properties of the nanotoxic pollutant are unknown (Andrione et al 2017). In contrary, we are exposed to materials, which are integrated into composites that are potentially manufactured using uncontrolled, unpurified, and very complex processes.…”

“…There is no fundamentally different modus operandi of nanomaterial governance in USA or Europe. The authorities emphasize reproducible studies in context with a correct nanosafety evaluation (Andrione et al 2017;Gottardo et al 2017).…”

Adaptations during Maturation in an Identified Honeybee Interneuron Responsive to Waggle Dance Vibration Signals

“…Several studies have investigated the neural basis of such behavioral versatility by studying structural changes in the honeybee brain with age and social role, mainly focusing on the mushroom body (Groh, et al, 2006, 2012; Groh and Meinertzhagen, 2010). Although most developmental changes in the honeybee brain occur during pupal and larval stages (Devaud and Masson, 1999; Ganeshina et al, 2000), considerable age-dependent and experience-dependent anatomic changes have been described at the level of subregions in the adult honeybee antennal lobe (Winnington et al, 1996; Sigg et al, 1997; Morgan et al, 1998; Brown et al, 2004; Andrione et al, 2017; Arenas et al, 2013) and the mushroom body (Withers et al, 1993, 1995; Durst et al, 1994; Fahrbach et al, 1998; Wolschin et al, 2009), as well as at the level of single mushroom body neurons (Farris et al, 2001). In addition, electrophysiological properties of honeybee neurons also mature with age and experience in the antennal lobe (Wang et al, 2005) and in the mushroom body (Kiya et al, 2007).…”