Biology subjects

Prieto-Godino, L. L.

Publications and source records attributed to Prieto-Godino, L. L..

14 recordsLinked to original sources

bioRxiv2026

Natural statistics of host odours predict species-specific olfactory behaviours in Drosophilids

Animals rely on olfaction to locate food, mates, and suitable habitats, yet natural odour environments contain thousands of volatile molecules, creating a high-dimensional sensory problem for both nervous systems and the researchers who study them 1-5. For example, a banana emits around 100 individual volatiles4,6. It remains unclear which components of complex odour blends animals have evolved to use as behavioural cues. Here, combining fieldwork, chemical and behavioural analyses, we show across multiple Drosophila species that behaviourally relevant cues can be predicted directly from the statistical structure of natural odour environments. Animals preferentially respond to components that are most distinctive within their natural host odour blends, and therefore most ecologically informative. These cues can be either major or minor blend components. Our results indicate that host-guided olfactory behaviours have evolved to exploit the statistical structure of natural odour environments by selectively targeting the most informative features of odour blends.

neuroscience↗

bioRxiv2025

Ecological cues orchestrate concerted courtship in a Drosophila host specialist

Mating decisions are often attributed to the sensory signaling between prospective sexual partners. Yet these interactions are also shaped by the broader environmental context in which they unfold, to appropriately align sexual arousal with reproductive opportunities. Here we show that in the host specialist Drosophila erecta mating is strictly contingent on the ecological and social environment generated as flies densely aggregate in groups on a food patch. We find that food volatiles directly promote male sexual arousal, triggering individuals to sample and pursue potential mates, giving rise to dynamic interactions across the group. The ensuing visual motion transforms each males visual field, which in turn further amplifies his arousal, generating a multisensory feedback loop that coordinately promotes courtship across individuals. D. erectas strict dependence on environmental cues appears latent in related species, such as D. melanogaster, where food odor can promote arousal but is dispensable for vigorous courtship. Comparative circuit analyses reveal that species-specific thresholds for sexual arousal reflect variation in how olfactory input modulates conserved nodes controlling courtship drive, rendering food volatiles a strict sensory gate only in D. erecta. Together, our findings highlight how ecological cues not directly tied to sexual signaling can profoundly influence reproductive behavior and reorganize the social landscape to ensure mating occurs in contexts where reproductive opportunities are abundant.

neuroscience↗

bioRxiv2025

Cross-species comparative connectomics reveals the evolution of an olfactory circuit

Animal behavioural diversity ultimately stems from variation in neural circuitry, yet how central neural circuits evolve remains poorly understood. Studies of neural circuit evolution often focus on a few elements within a network. However, addressing fundamental questions in evolutionary neuroscience, such as whether some elements are more evolvable than others, requires a more global and unbiased approach. Here, we used synapse-level comparative connectomics to examine how an entire olfactory circuit evolves. We compared the full antennal lobe connectome of the larvae of two closely related Drosophila species, D. melanogaster and D. erecta, which differ in their ecological niches and odour-driven behaviours. We found that evolutionary change is unevenly distributed across the network. Some features, including neuron types, neuron numbers and interneuron-to-interneuron connectivity, are highly conserved. These conserved elements delineate a core circuit blueprint presumably required for fundamental olfactory processing. Superimposed on this scaffold, we find rewiring changes that mirror each species ecologies, including a systematic shift in the excitation-to-inhibition balance in the feedforward pathways. We further show that some neurons have changed more than others, and that even within individual neurons some synaptic elements remain conserved while others display major species-specific changes, suggesting evolutionary hot-spots within the circuit. Our findings reveal constrained and adaptable elements within olfactory networks, and establish a framework for identifying general principles in the evolution of neural circuits underlying behaviour.

neuroscience↗

bioRxiv2023

Sensory neuron population expansion enhances odour tracking through relaxed projection neuron adaptation

The evolutionary expansion of sensory neuron populations detecting important environmental cues is widespread, but functionally enigmatic. We investigated this phenomenon through comparison of homologous neural pathways of Drosophila melanogaster and its close relative Drosophila sechellia, an extreme specialist for Morinda citrifolia noni fruit. D. sechellia has evolved species-specific expansions in select, noni-detecting olfactory sensory neuron (OSN) populations, through multigenic changes. Activation and inhibition of defined proportions of neurons demonstrate that OSN population increases contribute to stronger, more persistent, noni-odor tracking behavior. These sensory neuron expansions result in increased synaptic connections with their projection neuron (PN) partners, which are conserved in number between species. Surprisingly, having more OSNs does not lead to greater odor-evoked PN sensitivity or reliability. Rather, pathways with increased sensory pooling exhibit reduced PN adaptation, likely through weakened lateral inhibition. Our work reveals an unexpected functional impact of sensory neuron expansions to explain ecologically-relevant, species-specific behavior.

neuroscience↗

bioRxiv2023

Divergent evolution of sleep functions

Most living organisms have evolved to synchronize their biological activities with the earths rotation, a daily regulation of biology and behaviour controlled by an evolutionary conserved molecular machinery known as the circadian clock. For most animals, circadian mechanisms are meant to maximize their exposure to positive activities (e.g.: social interactions, mating, feeding - generally during the day) and minimize their exposure to peril (e.g.: predation, weather, darkness - generally during the night1). On top of circadian regulation, some behaviours also feature a second layer of homeostatic control acting as a fail-safe to ensure important activities are not ignored. Sleep is one of these behaviours: largely controlled by the circadian clock for its baseline appearance, it is at the same time modulated by a - poorly understood - homeostatic regulator ensuring animals obey their species-specific amount of daily sleep2. An evolutionary conserved homeostatic control is often considered the main evidence for a core biological function of sleep beyond the trivial one (that is: keeping us out of trouble by limiting our energy expenditure and exposure to danger3,4) and it is hypothesized that sleep evolved around this mysterious basic biological function. Here we characterize sleep regulation in a group of seven species of the Drosophila genus at key evolutionary distances and representing a variety of ecological niche adaptations. We show that the spontaneous circadian-driven aspects of sleep are conserved among all species but the homeostatic regulation, unexpectedly, is not. We uncover differences in the behavioural, cell-biological and neuro-pharmacological aspects of sleep and suggest that, in Drosophilids, sleep primarily evolved to satisfy a circadian role, keeping animals immobile during dangerous hours of the day. The homeostatic functions of sleep evolved independently, in a species-specific fashion, and are not conserved.

evolutionary biology↗

bioRxiv2022

Tsetse flies choose birthing sites guided by environmental but not pheromonal cues

Tsetse flies significantly impact public health and economic development in sub-Saharan African countries by transmitting the fatal disease African trypanosomiasis. Unusually, instead of laying eggs, tsetse birth a single larva that immediately burrows into the soil to pupate. Where the female chooses to larviposit is therefore crucial for offspring survival. Previous studies showed that a putative larval pheromone, n-pentadecane, attracts gravid female Glossina morsitans morsitans to appropriate larviposition sites. However, this attraction could not be reproduced in field experiments. Here, we resolve this disparity by designing naturalistic laboratory experiments that closely mimic the characteristics found in the wild. We show that gravid tsetse were neither attracted to the putative pheromone nor, interestingly, to pupae placed in the soil. In contrast, females appear to choose larviposition sites based on environmental cues. We conclude that it is the substrate, rather than larval pheromones, which drives larviposition site selection under naturalistic conditions.

animal behavior and cognition↗

bioRxiv2022

OptoPi: An open source flexible platform for the analysis of small animal behaviour

Behaviour is the ultimate output of neural circuit computations, and therefore its analysis is a cornerstone of neuroscience research. However, every animal and experimental paradigm requires different illumination conditions to capture and, in some cases, manipulate specific behavioural features. This means that researchers often develop, from scratch, their own solutions and experimental set-ups. Here, we present OptoPi, an open source, affordable ([~] {pound}600), behavioural arena with accompanying multi-animal tracking software. The system features highly customisable and reproducible visible and infrared illumination and allows for temporally precise optogenetic stimulation. OptoPi acquires images using a Raspberry Pi camera, features motorised LED-based illumination, Arduino control, as well as spectrum and irradiance monitoring to fine-tune illumination conditions with real time feedback. Our open-source software (BIO) can be used to simultaneously track multiple animals while accurately keeping individual animals identity both in on-line and off-line modes. We demonstrate the functionality of OptoPi by recording and tracking under different illumination conditions the spontaneous behaviour of larval zebrafish as well as adult Drosophila flies and their first instar larvae, an experimental animal that due to its small size and transparency has classically been hard to track. Further, we showcase OptoPis optogenetic capabilities through a series of experiments using transgenic Drosophila larvae.

neuroscience↗

bioRxiv2021

Olfactory receptor-dependent receptor repression in Drosophila

In olfactory systems across phyla, most sensory neurons transcribe a single olfactory receptor gene selected from a large genomic repertoire. We describe novel receptor gene-dependent mechanisms that ensure singular expression of receptors encoded by a tandem gene array in Drosophila. Transcription from upstream genes in the cluster runs through the coding region of downstream loci to inhibit their expression in cis, via transcriptional interference. Moreover, one receptor blocks expression of other receptor proteins in trans through a post-transcriptional mechanism. These repression mechanisms operate in endogenous neurons to ensure their unique expression. Our data provide evidence for inter-olfactory receptor regulation in invertebrates, and highlight unprecedented, but potentially widespread, mechanisms for ensuring exclusive expression of chemosensory receptors, and other protein families, encoded by tandemly-arranged genes.

neuroscience↗

bioRxiv2021

Molecular reconstruction of recurrent evolutionary switching in olfactory receptor specificity

Olfactory receptor repertoires exhibit remarkable functional diversity, but how these proteins have evolved is poorly understood. Through analysis of extant and ancestrally-reconstructed drosophilid olfactory receptors from the Ionotropic Receptor (IR) family, we investigated evolution of two organic acid-sensing receptors, IR75a and IR75b. Despite their low amino acid identity, we identify a common "hotspot" in their ligand-binding pocket that has a major effect on changing the specificity of both IRs, as well as at least two distinct functional transitions in IR75a during evolution. Ligand-docking into IR models predicts that the hotspot does not contact odor molecules, suggesting that this residue indirectly influences ligand/receptor interactions. Moreover, we show that odor specificity is refined by changes in additional, receptor-specific sites, including those outside the ligand-binding pocket. Our work reveals how a core, common determinant of ligand-tuning acts within epistatic and allosteric networks of substitutions to lead to functional evolution of olfactory receptors.

neuroscience↗

bioRxiv2020

20 years of African Neuroscience: Waking a sleeping giant

Understanding the function and dysfunction of the brain remains one of the key challenges of our time. However, an overwhelming majority of brain research is carried out in the Global North, by a minority of well-funded and intimately interconnected labs. In contrast, with an estimated one neuroscientist per million people in Africa, news about neuroscience research from the Global South remains sparse. Clearly, devising new policies to boost Africa’s neuroscience landscape is imperative. However, the policy must be based on accurate data, which is largely lacking. Such data must reflect the extreme heterogeneity of research outputs across the continent’s 54 countries distributed over an area larger than USA, Europe and China combined. Here, we analysed all of Africa’s Neuroscience output over the past 21 years. Uniquely, we individually verified in each of 12,326 publications that the work was indeed performed in Africa and led by African-based researchers. This step is critical: previous estimates grossly inflated figures, because many of Africa’s high-visibility publications are in fact the result of internationally led collaborations, with most work done outside of Africa. The remaining number of African-led Neuroscience publications was 5,219, on average only ~5 per country and year. From here, we extracted metrics such as the journal and citations, as well as detailed information on funding, international collaborations and the techniques and model systems used. We link these metrics to demographic data and indicators of mobility and economy. For reference, we also extracted the same metrics from 220 randomly selected publications each from the UK, USA, Australia, Japan and Brazil. Our unique dataset allows us to gain accurate and in-depth information on the current state of African Neuroscience research, and to put it into a global context. This in turn allows us to make actionable recommendations on how African research might best be supported in the future.Competing Interest StatementThe authors have declared no competing interest.View Full Text

scientific communication and education↗

bioRxiv2020

LED Zappelin': An open source LED controller for arbitrary spectrum visual stimulation and optogenetics during 2-photon imaging.

Two-photon (2P) microscopy is a cornerstone technique in neuroscience research. However, combining 2P imaging with spectrally arbitrary light stimulation can be challenging due to crosstalk between stimulation light and fluorescence detection. To overcome this limitation, we present a simple and low-cost electronic solution based on an ESP32 microcontroller and a TLC5947 LED driver to rapidly time-interleave stimulation and detection epochs during scans. Implemented for less than $100, our design can independently drive up to 24 arbitrary spectrum LEDs to meet user requirements. We demonstrate the utility of our stimulator for colour vision experiments on the in vivo tetrachromatic zebrafish retina and for optogenetic circuit mapping in Drosophila. https://github.com/BadenLab/LED-Zappelin

neuroscience↗

bioRxiv2019

Divergent excitation two photon microscopy for 3D random access mesoscale imaging at single cell resolution

ABSTACTIn neuroscience, diffraction limited two-photon (2P) microscopy is a cornerstone technique that permits minimally invasive optical monitoring of neuronal activity. However, most conventional 2P microscopes impose significant constraints on the size of the imaging field-of-view and the specific shape of the effective excitation volume, thus limiting the scope of biological questions that can be addressed and the information obtainable. Here, employing divergent beam optics (DBO), we present an ultra-low-cost, easily implemented and flexible solution to address these limitations, offering a several-fold expanded three-dimensional field of view that also maintains single-cell resolution. We show that this implementation increases both the space-bandwidth product and effective excitation power, and allows for straight-forward tailoring of the point-spread-function. Moreover, rapid laser-focus control via an electrically tunable lens now allows near-simultaneous imaging of remote regions separated in three dimensions and permits the bending of imaging planes to follow natural curvatures in biological structures. Crucially, our core design is readily implemented (and reversed) within a matter of hours, and fully compatible with a wide range of existing 2P customizations, making it highly suitable as a base platform for further development. We demonstrate the application of our system for imaging neuronal activity in a variety of examples in mice, zebrafish and fruit flies.

neuroscience↗

bioRxiv2019

Functional integration of \"undead\" neurons in the olfactory system

Programmed cell death (PCD) is widespread during neurodevelopment, typically eliminating the surpluses of neuronal production. Employing the Drosophila olfactory system, we examined the potential of cells fated to die to contribute to circuit evolution. Inhibition of PCD is sufficient to generate many new cells that express neural markers and exhibit odor-evoked activity. These \"undead\" neurons express a subset of olfactory receptors that, intriguingly, is enriched for recent receptor duplicates and include some normally found in other chemosensory organs and life-stages. Moreover, undead neuron axons integrate into the olfactory circuitry in the brain, forming novel receptor/glomerular couplings. Comparison of homologous olfactory lineages across drosophilids reveals natural examples of fate changes from death to a functional neuron. Finally, we provide evidence that PCD contributes to evolutionary differences in carbon dioxide-sensing circuit formation in Drosophila and mosquitoes. These results reveal the remarkable potential of alterations in PCD patterning to evolve new neural pathways.

neuroscience↗

bioRxiv2018

In vivo assembly and trafficking of olfactory Ionotropic Receptors

lonotropic Receptors (IRs) are a large, divergent subfamily of ionotropic glutamate receptors(iGluRs), with roles in chemosensation, thermosensation and hygrosensation. Analogous to the synaptic targeting mechanisms of their iGluR ancestors, IRs are thought to form complexes of broadly-expressed co-receptors and selectively-expressed tuning receptors to localise to sensory cilia. While tuning receptors extracellular ligand-binding domain (LBD) defines sensory specificity, the role of this domain in co-receptors is unclear. We identify a coreceptor-specific sequence in the LBD, which contains a single N-glycosylation site. Combining molecular genetic and cell biological analyses, we show that this site is dispensable for assembly of IR complexes in olfactory sensory neurons, but essential for endoplasmic reticulum exit of some,but not all, IR complexes. Our data reveal an important role for the IR co-receptor LBD in control of intracellular transport, provide novel insights into the stoichiometry and assembly of IR complexes, and uncover an unexpected heterogeneity in the trafficking regulation of this sensory receptor family.

neuroscience↗