We are interested in understanding the molecular mechanisms underlying behavioral plasticity on three major time scales: 1. Evolutionary time scale: we use genetic and genomic approaches to understand mechanisms that underlie behavioral variations between individuals as well as between species. These studies will help understand the role of behavioral phenotypes in driving evolution, and the role of behavior in speciation. 2. Developmental time scale: we study mechanisms underlying changes in specific behaviors expressed by single individuals over their lifetime, with specific emphasis on processes that affect neuronal plasticity at the sensory and central levels. 3. Physiological time scale: we study mechanisms underlying changes in behavior in response to acute changes in the physical and social environements of individuals. Here we focus on understanding how behaviorally specific stimuli activate specific neuronal circuits, which results in the release of a specific behavior. The Ben-Shahar lab studies various projects that are related to one or more of the above processes using insect models. Although we are currently focusing on the powerful genetic model Drosophila melanogaster (the fruit fly), we are also developing projects that will utilize the emerging model for complex social behaviors, the European honey bee, Apis mellifera. Work in our lab is at the interface of behavior, genetics, genomics, molecular and cellular biology, and neurophysiology. We hope these studies will result in an integrative understanding of the mechanisms for behavioral plasticity. Some of the projects currently investigated in the lab are described below.

Neuronal functions of DEG/ENaC channels

Degenerin/ epithelial sodium channels (DEG/ENaC) form non-voltage-gated, amiloride-sensitive cation channels. The active Deg/ENaC channel is comprised of three to nine independent subunits. Each subunit has two transmembrane domains, two short intracellular domains and a large extracellular loop, which is a characteristic of the family. The Deg/ENaC family seems to be animal specific and members have been identified in diverse species. Different subunits are enriched in peripheral and central neurons, and several members of the family contribute to mechanosensation, pH sensing, or are activated by peptides, but for most, the physiological function is still unknown. The Drosophila genome encodes for 31 members of the family, which are named pickpocket genes 1-31 (ppk). We use the fly as a model to understand the central and peripheral neuronal roles of these Deg/ENaC subunits with genetic, behavioral, and physiological tools. We are currently investigating the role of multiple family members in processes such as chemosensation, mechanosensation and proprioception, as well as the possible role of some subunits in synaptic plasticity.

Evolution and function of pheromonal communication systems

Animals use various sensory modalities to identify appropriate mates. We use the power of Drosophila genetics to understand the genetic and neuronal basis for species recognition and mating decisions, especially in the context of pheromonal signaling. We ask how these systems function, and how they may have evolved by taking advantage of the wealth of state-of-the-art genetic and genomic tools available for a group of closely related Drosophila species.

Molecular mechanisms for the neuronal stress response

In order to maintain functional ionic gradients across their membranes during physical and biological stresses, neurons need to adjust their electrical properties. Understanding how such homeostatic adjustments are made is important, since disruptions in neuronal homeostasis have been implicated in various behavioral and neuronal pathologies, such as seizures and cognitive deficits, as well as in certain psychiatric conditions.Established models propose that the regulation of neuronal homeostasis requires changes in the relative abundances of potassium and sodium channels at the membrane. We use genetics, behavioral, and neuronal tools to better understand how these channels are regulated in response to environmental stresses such as heat.

Molecular evolution of eusociality

We use genetic and genomic apraoches to study how eusocial ("true social") traits evolved in social bees, ants, and wasps. We are specifically focused on the possible function of regulatory non-coding RNAs, such as miRNAs, in the regulation of social behavioral traits in honey bees.