Non-optimality in C. elegans connectome

Generally, components of a system can deviate from optimality at different rates. To visualize this, think of a two component system, with x1 and x2. Imagine that x1 has a higher probability of being in a non-optimal state, or in other words, has a more slowly decreasing objective function: Perez-Escudero et al (’09) were interested [...]

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In vivo optogenetics in C. elegans

Two independent studies just published (here and here, summarized here) have taken optogenetics to in vivo, free-moving C. elegans. One of the key technical advances is real-time registration of where the nematode is moving, which allows the microscopic stage’s motors to move, keeping the worm centered. Liefer et al’s system has speed of ~50 frames [...]

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Neural macro connectivity and gene expression

French et al explore this link, looking at the correlation between gene expression in the mouse in and connectivity in homologous brain regions of the rat. This is their conceptual scheme: Of their 142 common regions, 112 have efferent (outgoing) connections, and 141 have afferent (incoming) connections. There are 5216 outgoing connections and 6110 incoming [...]

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