The microbiota promotes social behavior by modulating microglial remodeling of forebrain neurons.

Host-associated microbiotas guide the trajectory of developmental programs, and altered microbiota composition is linked to neurodevelopmental conditions such as autism spectrum disorder. Recent work suggests that microbiotas modulate behavioral phenotypes associated with these disorders. We discovered that the zebrafish microbiota is required for normal social behavior and reveal a molecular pathway linking the microbiota, microglial remodeling of neural circuits, and social behavior in this experimentally tractable model vertebrate.

A conserved transcriptional fingerprint of multi-neurotransmitter neurons necessary for social behavior.

Background: An essential determinant of a neuron's functionality is its neurotransmitter phenotype. We previously identified a defined subpopulation of cholinergic neurons required for social orienting behavior in zebrafish.

Results: We transcriptionally profiled these neurons and discovered that they are capable of synthesizing both acetylcholine and GABA.

Egr1 Is Necessary for Forebrain Dopaminergic Signaling during Social Behavior.

Finding the link between behaviors and their regulatory molecular pathways is a major obstacle in treating neuropsychiatric disorders. The immediate early gene (IEG) is implicated in the etiology of neuropsychiatric disorders, and is linked to gene pathways associated with social behavior. Despite extensive knowledge of gene regulation at the molecular level, it remains unclear how EGR1 deficits might affect the social component of these disorders.

Late onset of Synaptotagmin 2a expression at synapses relevant to social behavior.

As they form, synapses go through various stages of maturation and refinement. These steps are linked to significant changes in synaptic function, potentially resulting in emergence and maturation of behavioral outputs. Synaptotagmins are calcium-sensing proteins of the synaptic vesicle exocytosis machinery, and changes in Synaptotagmin proteins at synapses have significant effects on vesicle release and synaptic function.

Forebrain Control of Behaviorally Driven Social Orienting in Zebrafish.

Deficits in social engagement are diagnostic of multiple neurodevelopmental disorders, including autism and schizophrenia [1]. Genetically tractable animal models like zebrafish (Danio rerio) could provide valuable insight into developmental factors underlying these social impairments, but this approach is predicated on the ability to accurately and reliably quantify subtle behavioral changes. Similarly, characterizing local molecular and morphological phenotypes requires knowledge of the neuroanatomical correlates of social behavior.