@article {69456,
	title = {Hue selectivity from recurrent circuitry in Drosophila},
	journal = {Nat Neurosci},
	year = {2024},
	month = {2024 May 16},
	abstract = {<p>In the perception of color, wavelengths of light reflected off objects are transformed into the derived quantities of brightness, saturation and hue. Neurons responding selectively to hue have been reported in primate cortex, but it is unknown how their narrow tuning in color space is produced by upstream circuit mechanisms. We report the discovery of neurons in the Drosophila optic lobe with hue-selective properties, which enables circuit-level analysis of color processing. From our analysis of an electron microscopy volume of a whole Drosophila brain, we construct a connectomics-constrained circuit model that accounts for this hue selectivity. Our model predicts that recurrent connections in the circuit are critical for generating hue selectivity. Experiments using genetic manipulations to perturb recurrence in adult flies confirm this prediction. Our findings reveal a circuit basis for hue selectivity in color vision.</p>
},
	issn = {1546-1726},
	doi = {10.1038/s41593-024-01640-4},
	author = {Christenson, Matthias P and Sanz Diez, Alvaro and Heath, Sarah L and Saavedra-Weisenhaus, Maia and Adachi, Atsuko and Nern, Aljoscha and Abbott, L F and Behnia, Rudy}
}
@article {68885,
	title = {A rise-to-threshold process for a relative-value decision.},
	journal = {Nature},
	volume = {619},
	year = {2023},
	month = {2023 Jul 05},
	pages = {563-571},
	abstract = {<p>Whereas progress has been made in the identification of neural signals related to rapid, cued decisions, less is known about how brains guide and terminate more ethologically relevant decisions in which an animal{\textquoteright}s own behaviour governs the options experienced over minutes. Drosophila search for many seconds to minutes for egg-laying sites with high relative value and have neurons, called oviDNs, whose activity fulfills necessity and sufficiency criteria for initiating the egg-deposition motor programme. Here we show that oviDNs express a calcium signal that (1) dips when an egg is internally prepared (ovulated), (2) drifts up and down over seconds to minutes-in a manner influenced by the relative value of substrates-as a fly determines whether to lay an egg and (3) reaches a consistent peak level just before the abdomen bend for egg deposition. This signal is apparent in the cell bodies of oviDNs in the brain and it probably reflects a behaviourally relevant rise-to-threshold process in the ventral nerve cord, where the synaptic terminals of oviDNs are located and where their output can influence behaviour. We provide perturbational evidence that the egg-deposition motor programme is initiated once this process hits a threshold and that subthreshold variation in this process regulates the time spent considering options and, ultimately, the choice taken. Finally, we identify a small recurrent circuit that feeds into oviDNs and show that activity in each of its constituent cell types is required for laying an egg. These results argue that a rise-to-threshold process regulates a relative-value, self-paced decision and provide initial insight into the underlying circuit mechanism for building this process.</p>
},
	issn = {1476-4687},
	doi = {10.1038/s41586-023-06271-6},
	author = {Vijayan, Vikram and Wang, Fei and Wang, Kaiyu and Chakravorty, Arun and Adachi, Atsuko and Akhlaghpour, Hessameddin and Dickson, Barry J and Maimon, Gaby}
}
