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Learn Mem

Title:		Steroid hormone (20-hydroxyecdysone) modulates the acquisition of aversive olfactory memories in pollen forager honeybees
Author(s):		Geddes LH; McQuillan HJ; Aiken A; Vergoz V; Mercer AR;
Address:		"Department of Zoology, University of Otago, Dunedin, New Zealand 9054"
Journal Title:		Learn Mem
Year:		2013
Volume:		20130715
Issue:		8
Page Number:		399 - 409
DOI:		10.1101/lm.030825.113
ISSN/ISBN:		1549-5485 (Electronic) 1072-0502 (Linking)
Abstract:		"Here, we examine effects of the steroid hormone, 20-hydroxyecdysone (20-E), on associative olfactory learning in the honeybee, Apis mellifera. 20-E impaired the bees' ability to associate odors with punishment during aversive conditioning, but did not interfere with their ability to associate odors with a food reward (appetitive learning). The steroid had a significant impact also on the expression of amine-receptor genes in centers of the brain involved in the formation and recall of associative olfactory memories (mushroom bodies). 20-E increased expression of the dopamine receptor gene, Amdop2, and reduced the expression of the putative dopamine/ecdysone receptor gene, Amgpcr19. Interestingly, Amgpcr19 tended to be highly expressed in the brains of foragers that exhibited strong aversive learning, but expressed at lower levels in bees that performed well in appetitive learning assays. In 2-d-old bees, transcript levels of the same gene could be reduced by queen mandibular pheromone, a pheromone that blocks aversive learning in young worker bees. As ecdysteroid levels rise to a peak approximately 2 d after adult emergence and then fall to low levels in foragers, we examined aversive learning also in young worker bees. Aversive learning performance in 2-d-old bees was consistently poor. The results of this study indicate that learning in honeybees can be modulated by ecdysteroids. They highlight, in addition, a potential involvement of the putative dopamine/ecdysone receptor, AmGPCR19, in hormonal regulation of associative olfactory learning in the honeybee"
Keywords:		"Animals Bees Conditioning, Classical/*physiology Ecdysterone/*pharmacology Gene Expression/drug effects Memory/drug effects/*physiology Receptors, Biogenic Amine/genetics/metabolism Receptors, Dopamine/genetics/metabolism Receptors, Steroid/*metabolism Sm;"
Notes:		"MedlineGeddes, Lisa H McQuillan, H James Aiken, Alastair Vergoz, Vanina Mercer, Alison R eng Research Support, Non-U.S. Gov't 2013/07/17 Learn Mem. 2013 Jul 15; 20(8):399-409. doi: 10.1101/lm.030825.113"