Environment- and Age-Dependent Plasticity of Synaptic Complexes in the Mushroom Bodies of Honeybee Queens
- 1 June 2006
- journal article
- research article
- Published by S. Karger AG in Brain, Behavior and Evolution
- Vol. 68 (1), 1-14
- https://doi.org/10.1159/000092309
Abstract
Diversity in behavior plays a crucial role for the division of labor in insect societies. Social insects such as honeybees provide excellent model systems to investigate neuronal principles underlying behavioral plasticity. The two female castes, queens and workers, differ substantially in anatomy, physiology, aging and behavior. The different phenotypes are induced by environmental factors rather than genetic differences. Here we investigated environment- and age-dependent effects on the synaptic organization within higher order neuropils of the honeybee brain. Synaptic complexes (microglomeruli) in sensory-input regions of the mushroom bodies, prominent higher sensory integration centers, were analyzed quantitatively using fluorescent markers and confocal microscopy. Pre- and postsynaptic compartments of individual microglomeruli were labeled by anti-synapsin immunolabeling and f-actin detection with phalloidin in dendritic spines of mushroom-body intrinsic neurons. The results demonstrate that in queens the numbers of microglomeruli in the olfactory and visual input regions of the mushroom-body calyx are significantly lower than in workers. In queens raised in incubators, micro-glomeruli were affected by differences in pupal rearing temperature within the range of naturally occurring temperatures (32-36 degrees C). The highest numbers of micro-glomeruli developed at a lower temperature compared to workers (33.5 vs. 34.5 degrees C). We found a striking adult plasticity of microglomeruli numbers throughout the extended life-span of queens. Whereas microglomeruli in the olfactory lip increased with age (similar to 55%), microglomeruli in the visual collar significantly decreased (similar to 35%). We propose that developmental and adult plasticity of the synaptic circuitry in the mushroom-body calyx might underlie caste- and age-specific adaptations in behavior.Keywords
This publication has 53 references indexed in Scilit:
- F‐actin at identified synapses in the mushroom body neuropil of the insect brainJournal of Comparative Neurology, 2004
- Development and morphology of Class II Kenyon cells in the mushroom bodies of the honey bee, Apis melliferaJournal of Comparative Neurology, 2004
- Neuronal Activity and Adenylyl Cyclase in Environment-Dependent Plasticity of Axonal Outgrowth inDrosophilaJournal of Neuroscience, 2004
- Segregation of visual input to the mushroom bodies in the honeybee (Apis mellifera)Journal of Comparative Neurology, 2002
- Organization of the honey bee mushroom body: Representation of the calyx within the vertical and gamma lobesJournal of Comparative Neurology, 2002
- Localization of a Short-Term Memory in DrosophilaScience, 2000
- Neurogenesis is absent in the brains of adult honey bees and does not explain behavioral neuroplasticityNeuroscience Letters, 1995
- Development and experience lead to increased volume of subcompartments of the honeybee mushroom bodyBehavioral and Neural Biology, 1994
- Hormonally mediated changes in simple reflex circuits during metamorphosis in ManducaJournal of Neurobiology, 1990
- The brain of the honeybee Apis mellifera . I. The connections and spatial organization of the mushroom bodiesPhilosophical Transactions of the Royal Society of London. B, Biological Sciences, 1982