A visual motion detection circuit suggested by Drosophila connectomics.

Animal behaviour arises from computations in neuronal circuits, but our understanding of these computations has been frustrated by the lack of detailed synaptic connection maps, or connectomes. For example, despite intensive investigations over half a century, the neuronal implementation of local motion detection in the insect visual system remains elusive. Here we develop a semi-automated pipeline using electron microscopy to reconstruct a connectome, containing 379 neurons and 8,637 chemical synaptic contacts, within the Drosophila optic medulla. By matching reconstructed neurons to examples from light microscopy, we assigned neurons to cell types and assembled a connectome of the repeating module of the medulla. Within this module, we identified cell types constituting a motion detection circuit, and showed that the connections onto individual motion-sensitive neurons in this circuit were consistent with their direction selectivity. Our results identify cellular targets for future functional investigations, and demonstrate that connectomes can provide key insights into neuronal computations.

Source interpretation: teaching students with and without LD to read and write historically.

We review domain-specific teaching approaches for students with learning disabilities in social studies, then present De La Paz's 2005 historical reasoning strategy so that readers understand the rationale for and have information on each stage of instruction. Next, we highlight the role of self-regulation for the reasoning process. We then turn to describing the role of each teacher (Morales as the social studies educator and Winston as the special educator), first as they collaborate with De La Paz and each other, then as Morales works alone, 1 year later. Implications are given for changes in teaching. The topic of women's suffrage is used throughout the article to highlight the teaching approach and to present student work.