Brain plasticity in Diptera and Hymenoptera

Abstract

To mediate different types of behaviour, nervous systems must coordinate the proper operation of their neural circuits as well as short-and long-term alterations that occur within those circuits. The latter ultimately devolve upon specific changes in neuronal structures, membrane properties and synaptic connections that are all examples of plasticity. This reorganization of the adult nervous system is shaped by internal and external influences both during development and adult maturation. In adults, behavioural experience is a major driving force of neuronal plasticity studied particularly in sensory systems. The range of adaptation depends on features that are important to a particular species, so that learning is essential for foraging in honeybees, while regenerative capacities are important in hemimetabolous insects with long appendages. Experience is usually effective during a critical period in early adult life, when neural function becomes tuned to future conditions in an insect's life. Changes occur at all levels, in synaptic circuits, neuropile volumes, and behaviour. There are many examples, and this review incorporates only a select few, mainly those from Diptera and Hymenoptera.

The gene expression network regulating queen brain remodeling after insemination and its parallel use in ants with reproductive workers

“…It is well known that the structure of a brain can be modified by influences from the social and physical environment even after brain development has been completed and that this process is normally accompanied by changes in memory and behavior ( 39 ). However, in comparison to the highly variable and largely unpredictable responses documented in these and other studies ( 39 – 42 ), the phenotypic changes in social insect queens following insemination are both profound and predictable. Queens are normally inseminated on a single day early in adult life, they will never re-mate again, and they will specialize on highly efficient reproductive functionality within a few weeks.…”

Reversible plasticity in brain size, behaviour and physiology characterizes caste transitions in a socially flexible ant (Harpegnathos saltator)

“…Similarly, research on Drosophila has shown that brain regions that were experimentally stunted during early adult life were unable to recover in mature adults [33]. The majority of research on brain plasticity in insects has focused on unidirectional changes rather than reversibility [34,35].…”

Dengue virus infection changes Aedes aegypti oviposition olfactory preferences

“…It is generally known that insects, including mosquitoes, are capable of information retention, acquired either during larval development, hatching or foraging, and that new information could influence their behaviour 1 . In this study, we define the term of “olfactory learning” as change of olfactory preferences induced by exposure to odour.…”