Evidence of calcium signaling in mushroom body neurons via the honey bee dopamine receptor, AmDOP2
-
1
Otago University, Department of Zoology, New Zealand
A honey bee’s ability to modify its behaviour in response to environmental cues is vital for its survival and important also for the success of the colony as a whole. Learning which floral colours or odours are associated with food rewards, for example, and which environmental cues signal danger, impacts significantly on the behaviour of forager bees. Biogenic monoamines have been found to be key players in the neural events that underlie a bee’s ability to associate sensory inputs with a positive or negative outcome. Release of dopamine at the level of the mushroom bodies of the brain, for example, has been found to be critical for the acquisition of aversive olfactory memories and interestingly, there is evidence of dopamine’s involvement also in modulating responses in pathways that signal reward. Three honey bee (Apis mellifera L.) dopamine receptor genes have been identified and their receptor proteins characterized. While all 3 genes, Amdop1, Amdop2, and Amdop3, are expressed in the mushroom bodies of the brain, the extent and nature of their contributions to learning and memory processes remain unclear. Analyses of honey bee dopamine receptors in vitro, using heterologous expression techniques, suggest that all 3 receptors couple to adenylyl cyclase and signal by changing intracellular levels of cAMP. In addition, however, recent evidence suggests that changes in intracellular calcium may occur as a result of activation of AmDOP2. To determine whether activation of AmDOP2 receptors in situ elicits calcium signals, we examined the effects of dopamine on mushroom body neurons (Kenyon cells) in primary cell culture. We found that dopamine-mediated calcium responses could be detected in Kenyon cells maintained in culture for 24h, or 4 days, and that the percentage of cells responding to dopamine could be reduced significantly by pretreatment of cells with the dopamine receptor antagonist cis-(Z)-flupentixol (10 µM). Interestingly, dopamine-induced calcium signals could also be inhibited by 10 µM epinastine, a drug that is more commonly used to block responses to histamine and octopamine. As calcium signaling plays a critical role in long-term memory formation, we are examining the possibility that AmDOP2 contributes to the formation of long-term olfactory memories in the bee.
Keywords:
amdop2,
Calcium,
Dopamine,
Honeybee,
Learning,
receptor
Conference:
Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012.
Presentation Type:
Poster (but consider for student poster award)
Topic:
Learning, Memory and Behavioral Plasticity
Citation:
Ellen
C and
Mercer
A
(2012). Evidence of calcium signaling in mushroom body neurons via the honey bee dopamine receptor, AmDOP2.
Conference Abstract:
Tenth International Congress of Neuroethology.
doi: 10.3389/conf.fnbeh.2012.27.00136
Copyright:
The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers.
They are made available through the Frontiers publishing platform as a service to conference organizers and presenters.
The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated.
Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed.
For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions.
Received:
27 Apr 2012;
Published Online:
07 Jul 2012.
*
Correspondence:
Mr. Charles Ellen, Otago University, Department of Zoology, Dunedin, 9011, New Zealand, charles.ellen@otago.ac.nz