@article {64814, title = {Chronology-based architecture of descending circuits that underlie the development of locomotor repertoire after birth.}, journal = {eLife}, volume = {8}, year = {2019}, month = {2019 Feb 25}, abstract = {

The emergence of new and increasingly sophisticated behaviors after birth is accompanied by dramatic increase of newly established synaptic connections in the nervous system. Little is known, however, of how nascent connections are organized to support such new behaviors alongside existing ones. To understand this, in the larval zebrafish we examined the development of spinal pathways from hindbrain V2a neurons and the role of these pathways in the development of locomotion. We found that new projections are continually layered laterally to existing neuropil, and give rise to distinct pathways that function in parallel to existing pathways. Across these chronologically layered pathways, the connectivity patterns and biophysical properties vary systematically to support a behavioral repertoire with a wide range of kinematics and dynamics. Such layering of new parallel circuits equipped with systematically changing properties may be central to the postnatal diversification and increasing sophistication of an animal{\textquoteright}s behavioral repertoire.

}, issn = {2050-084X}, doi = {10.7554/eLife.42135}, author = {Pujala, Avinash and Koyama, Minoru} } @article {49535, title = {Brain-wide circuit interrogation at the cellular level guided by online analysis of neuronal function.}, journal = {Nature Methods}, volume = {15}, year = {2018}, month = {2018 Nov 30}, pages = {1117-1125}, abstract = {

Whole-brain imaging allows for comprehensive functional mapping of distributed neural pathways, but neuronal perturbation experiments are usually limited to targeting predefined regions or genetically identifiable cell types. To complement whole-brain measures of activity with brain-wide manipulations for testing causal interactions, we introduce a system that uses measuredactivity patterns to guide optical perturbations of any subset of neurons in the same fictively behaving larval zebrafish. First, a light-sheet microscope collects whole-brain data that are rapidly analyzed by a distributed computing system to generate functional brain maps. On the basis of these maps, the experimenter can then optically ablate neurons and image activity changes across the brain. We applied this method to characterize contributions of behaviorally tuned populations to the optomotor response. We extended the system to optogenetically stimulate arbitrary subsets of neurons during whole-brain imaging. These open-source methods enable delineating the contributions of neurons to brain-wide circuit dynamics and behavior in individual animals.

}, doi = {10.1038/s41592-018-0221-x}, author = {Vladimirov, Nikita and Wang, Chen and H{\"o}ckendorf, Burkhard and Pujala, Avinash and Tanimoto, Masashi and Mu, Yu and Yang, Chao-Tsung and Wittenbach, Jason and Freeman, Jeremy and Preibisch, Stephan and Koyama, Minoru and Keller, Philipp J and Ahrens, Misha B} } @article {49011, title = {Mutual inhibition of lateral inhibition: a network motif for an elementary computation in the brain.}, journal = {Current Opinion in Neurobiology}, volume = {49}, year = {2018}, month = {2018 Jan 16}, pages = {69-74}, abstract = {

A series of classical studies in non-human primates has revealed the neuronal activity patterns underlying decision-making. However, the circuit mechanisms for such patterns remain largely unknown. Recent detailed circuit analyses in simpler neural systems have started to reveal the connectivity patterns underlying analogous processes. Here we review a few of these systems that share a particular connectivity pattern, namely mutual inhibition of lateral inhibition. Close examination of these systems suggests that this recurring connectivity pattern ({\textquoteright}network motif{\textquoteright}) is a building block to enforce particular dynamics, which can be used not only for simple behavioral choice but also for more complex choices and other brain functions. Thus, a network motif provides an elementary computation that is not specific to a particular brain function and serves as an elementary building block in the brain.

}, issn = {1873-6882}, doi = {10.1016/j.conb.2017.12.019}, author = {Koyama, Minoru and Pujala, Avinash} }