Glutamatergic and GABAergic effects of fipronil on olfactory learning and memory in the honeybee.
We investigated here the role of transmissions mediated by GABA and glutamate-gated chloride channels (GluCls) in olfactory learning and memory in honeybees, both of these channels being a target for fipronil. To do so, we combined olfactory conditioning with injections of either the GABA- and glutamate-interfering fipronil alone, or in combination with the blocker of glutamate transporter L-trans-Pyrrolidine-2,4-Dicarboxylicacid (L-trans-PDC), or the GABA analog Trans-4-Aminocrotonic Acid (TACA). Our results show that a low dose of fipronil (0.1 ng/bee) impaired olfactory memory, while a higher dose (0.5 ng/bee) had no effect. The detrimental effect induced by the low dose of fipronil was rescued by the coinjection of L-trans-PDC but was rather increased by the coinjection of TACA. Moreover, using whole-cell patch-clamp recordings, we observed that L-trans-PDC reduced glutamate-induced chloride currents in antennal lobe cells. We interpret these results as reflecting the involvement of both GluCl and GABA receptors in the impairment of olfactory memory induced by fipronil.
Centre de Recherches sur Cognition Animale, Université Paul Sabatier Toulouse III-CNRS UMR 5169, 118 Route de Narbonne, 31062 Toulouse Cedex 04, France.
Abdessalam Kacimi
AK
El Hassani
Julien Pierre
JP
Dupuis
Monique
M
Gauthier
Catherine
C
Armengaud
D027322:Amino Acid Transport System X-AG / Q000037:antagonists & inhibitors / Q000378:metabolism; D000818:Animals; D001516:Bees / Q000187:drug effects* / Q000502:physiology; D018118:Chloride Channels / Q000378:metabolism; D002712:Chlorides / Q000378:metabolism; D003437:Crotonates / Q000494:pharmacology; D003998:Dicarboxylic Acids / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D018698:Glutamic Acid / Q000378:metabolism*; D019476:Insect Proteins / Q000378:metabolism; D007306:Insecticides / Q000008:administration & dosage / Q000494:pharmacology*; D007858:Learning / Q000187:drug effects / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects; D008568:Memory / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D014179:Neurotransmitter Uptake Inhibitors / Q000494:pharmacology; D055696:Olfactory Perception / Q000187:drug effects / Q000502:physiology; D011720:Pyrazoles / Q000008:administration & dosage / Q000494:pharmacology*; D011759:Pyrrolidines / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000031:analogs & derivatives / Q000378:metabolism*
D027322:Amino Acid Transport System X-AG; D018118:Chloride Channels; D002712:Chlorides; D003437:Crotonates; D003998:Dicarboxylic Acids; D019476:Insect Proteins; D007306:Insecticides; D014179:Neurotransmitter Uptake Inhibitors; D011720:Pyrazoles; D011759:Pyrrolidines; C055331:4-aminocrotonic acid; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; C083486:pyrrolidine-2,4-dicarboxylic acid; C082360:fipronil