Developmental history modulates adult olfactory behavioral preferences via regulation of chemoreceptor expression in Caenorhabditiselegans.

Developmental experiences play critical roles in shaping adult physiology and behavior. We and others previously showed that adult Caenorhabditiselegans which transiently experienced dauer arrest during development (postdauer) exhibit distinct gene expression profiles as compared to control adults which bypassed the dauer stage. In particular, the expression patterns of subsets of chemoreceptor genes are markedly altered in postdauer adults.

Diverse states and stimuli tune olfactory receptor expression levels to modulate food-seeking behavior.

Animals must weigh competing needs and states to generate adaptive behavioral responses to the environment. Sensorimotor circuits are thus tasked with integrating diverse external and internal cues relevant to these needs to generate context-appropriate behaviors. However, the mechanisms that underlie this integration are largely unknown.

Dendrites with specialized glial attachments develop by retrograde extension using SAX-7 and GRDN-1.

Dendrites develop elaborate morphologies in concert with surrounding glia, but the molecules that coordinate dendrite and glial morphogenesis are mostly unknown. offers a powerful model for identifying such factors. Previous work in this system examined dendrites and glia that develop within epithelia, similar to mammalian sense organs.

Cell Type-specific mRNA Purification in via Translating Ribosome Affinity Purification.

Cell type-specific molecular profiling is widely used to gain new insights into the diverse cell types that make up complex biological tissues. Translating ribosome affinity purification (TRAP) is a method in which the cell type-specific expression of epitope-tagged ribosomal subunits allows one to purify actively translating mRNAs without the need for cell sorting or fixation. We adapted this method for use in to identify novel transcripts in single cell types or to identify the effects of environmental changes on the transcriptomes of larger cohorts of cells.

Morphogenesis of neurons and glia within an epithelium.

To sense the outside world, some neurons protrude across epithelia, the cellular barriers that line every surface of our bodies. To study the morphogenesis of such neurons, we examined the amphid, in which dendrites protrude through a glial channel at the nose. During development, amphid dendrites extend by attaching to the nose via DYF-7, a type of protein typically found in epithelial apical ECM.

ASICs Mediate Food Responses in an Enteric Serotonergic Neuron that Controls Foraging Behaviors.

Animals must respond to the ingestion of food by generating adaptive behaviors, but the role of gut-brain signaling in behavioral regulation is poorly understood. Here, we identify conserved ion channels in an enteric serotonergic neuron that mediate its responses to food ingestion and decipher how these responses drive changes in foraging behavior. We show that the C.

A neuronal MAP kinase constrains growth of a Caenorhabditis elegans sensory dendrite throughout the life of the organism.

Neurons develop elaborate morphologies that provide a model for understanding cellular architecture. By studying C. elegans sensory dendrites, we previously identified genes that act to promote the extension of ciliated sensory dendrites during embryogenesis.

A Conserved Role for Girdin in Basal Body Positioning and Ciliogenesis.

Primary cilia are ubiquitous sensory organelles that mediate diverse signaling pathways. Cilia position on the cell surface is determined by the location of the basal body (BB) that templates the cilium. The mechanisms that regulate BB positioning in the context of ciliogenesis are largely unknown.

Shaping dendrites with machinery borrowed from epithelia.

The ciliated receptive endings of sensory cells and the dendrites of other neurons are shaped by adhesive interactions, many of which depend on machinery also present in epithelia. Sensory cells are shaped by interactions with support cells through adhesion junctions via the Crumbs complex, tight junction components such as claudins, as well as interactions with apical extracellular matrix composed of zona pellucida domain proteins. Neuronal dendrites are shaped by adhesion machinery that includes cadherins, catenins, afadin, L1CAM, CHL1, Sidekicks, Contactin and Caspr, many of which are shared with epithelia.

Ral mediates activity-dependent growth of postsynaptic membranes via recruitment of the exocyst.

Remodelling neuronal connections by synaptic activity requires membrane trafficking. We present evidence for a signalling pathway by which synaptic activity and its consequent Ca(2+) influx activate the small GTPase Ral and thereby recruit exocyst proteins to postsynaptic zones. In accord with the ability of the exocyst to direct delivery of post-Golgi vesicles, constitutively active Ral expressed in Drosophila muscle causes the exocyst to be concentrated in the region surrounding synaptic boutons and consequently enlarges the membrane folds of the postsynaptic plasma membrane (the subsynaptic reticulum, SSR).

The central nucleus of the amygdala is essential for acquiring and expressing conditional fear after overtraining.

The basolateral complex of the amygdala (BLA) is critical for the acquisition and expression of Pavlovian fear conditioning in rats. Nonetheless, rats with neurotoxic BLA lesions can acquire conditional fear after overtraining (75 trials). The capacity of rats with BLA lesions to acquire fear memory may be mediated by the central nucleus of the amygdala (CEA).