From Synapses to Circuits, Astrocytes Regulate Behavior.

Astrocytes are non-neuronal cells that regulate synapses, neuronal circuits, and behavior. Astrocytes ensheath neuronal synapses to form the tripartite synapse where astrocytes influence synapse formation, function, and plasticity. Beyond the synapse, recent research has revealed that astrocyte influences on the nervous system extend to the modulation of neuronal circuitry and behavior.

Sex-Specific Role for Dopamine Receptor D2 in Dorsal Raphe Serotonergic Neuron Modulation of Defensive Acoustic Startle and Dominance Behavior.

Brain networks underlying states of social and sensory alertness are normally adaptive, influenced by serotonin and dopamine (DA), and abnormal in neuropsychiatric disorders, often with sex-specific manifestations. Underlying circuits, cells, and molecules are just beginning to be delineated. Implicated is a subtype of serotonergic neuron denoted , distinguished by expression of the type-2 DA receptor () gene, inhibited cell-autonomously by DRD2 agonism in slice, and, when constitutively silenced in male mice, affects levels of defensive and exploratory behaviors (Niederkofler et al.

A single-cell transcriptomic and anatomic atlas of mouse dorsal raphe neurons.

Among the brainstem raphe nuclei, the dorsal raphe nucleus (DR) contains the greatest number of -lineage neurons, a predominantly serotonergic group distributed throughout DR subdomains. These neurons collectively regulate diverse physiology and behavior and are often therapeutically targeted to treat affective disorders. Characterizing neuron molecular heterogeneity and relating it to anatomy is vital for understanding DR functional organization, with potential to inform therapeutic separability.

Dystroglycan organizes axon guidance cue localization and axonal pathfinding.

Precise patterning of axon guidance cue distribution is critical for nervous system development. Using a murine forward genetic screen for novel determinants of axon guidance, we identified B3gnt1 and ISPD as required for the glycosylation of dystroglycan in vivo. Analysis of B3gnt1, ISPD, and dystroglycan mutant mice revealed a critical role for glycosylated dystroglycan in the development of several longitudinal axon tracts.