Biology subjects

Ahmed, O. M.

Publications and source records attributed to Ahmed, O. M..

6 recordsLinked to original sources

bioRxiv2025

Recent social experience alters song behavior in Drosophila

Innate behaviors are hardwired into the nervous system, allowing animals to produce them instinctively and without prior learning. This includes social behaviors (e.g., aggression, courtship) in most animals. If and how learning shapes such innate behaviors has not been systematically explored. Here, we investigate learning from social feedback in Drosophila. We use closed-loop optogenetics to systematically perturb the social experience of individual flies during courtship, and find that altered feedback changes the male flys innate courtship strategy, opening the door for investigating the neural and molecular basis of social plasticity in flies. TeaserMale flies adjust their innate communication strategy in response to systematic perturbation of social experience.

neuroscience↗

bioRxiv2025

High-speed whole-brain imaging in Drosophila

Recent advances in brain-wide recordings of small animals such as worms, fish, and flies have revealed complex activity involving large populations of neurons. In the Drosophila brain, with about 140,000 neurons, brain-wide recordings have been critical to uncovering widespread sensory and motor activity. However, current limitations in volumetric imaging rates hinder the accurate capture of fast neural dynamics. To improve the speed of volumetric imaging in Drosophila, we leverage the recently introduced light beads microscopy (LBM) method. We built a microscope and a LBM module tailored to fly brain experiments and used it to record brain-wide calcium signals in adult behaving flies at either 28 volumes per second or at 60 volumes per second (when selecting the central brain alone). We uncover fast-timescale auditory responses that are missed with standard volumetric imaging. We also demonstrate how temporal super-resolution can be combined with LBM data to uncover responses to single Drosophila courtship song pulses. This establishes LBM as a viable tool for capturing whole-brain activity at high spatial and temporal resolution in the fly.

neuroscience↗

bioRxiv2023

Transcriptional profiling of Drosophila male-specific P1 (pC1) neurons

In Drosophila melanogaster, the P1 (pC1) cluster of male-specific neurons both integrates sensory cues and drives or modulates behavioral programs such as courtship, in addition to contributing to a social arousal state. The behavioral function of these neurons is linked to the genes they express, which underpin their capacity for synaptic signaling, neuromodulation, and physiology. Yet, P1 (pC1) neurons have not been fully characterized at the transcriptome level. Moreover, it is unknown how the molecular landscape of P1 (pC1) neurons acutely changes after flies engage in social behaviors, where baseline P1 (pC1) neural activity is expected to increase. To address these two gaps, we use single cell-type RNA sequencing to profile and compare the transcriptomes of P1 (pC1) neurons harvested from socially paired versus solitary male flies. Compared to control transcriptome datasets, we find that P1 (pC1) neurons are enriched in 2,665 genes, including those encoding receptors, neuropeptides, and cell-adhesion molecules (dprs/DIPs). Furthermore, courtship is characterized by changes in[~] 300 genes, including those previously implicated in regulating behavior (e.g. DopEcR, Oct{beta}3R, Fife, kairos, rad). Finally, we identify a suite of genes that link conspecific courtship with the innate immune system. Together, these data serve as a molecular map for future studies of an important set of higher-order and sexually-dimorphic neurons.

neuroscience↗

bioRxiv2023

BIFROST: a method for registering diverse imagingdatasets

The heterogeneity of brain imaging methods in neuroscience provides rich data that cannot be captured by a single technique, and our interpretations benefit from approaches that enable easy comparison both within and across different data types. For example, comparing brain-wide neural dynamics across experiments and aligning such data to anatomical resources, such as gene expression patterns or connectomes, requires precise alignment to a common set of anatomical coordinates. However, this is challenging because registering in vivo functional imaging data to ex vivo reference atlases requires accommodating differences in imaging modality, microscope specification, and sample preparation. We overcome these challenges in Drosophila by building an in vivo reference atlas from multiphoton-imaged brains, called the Functional Drosophila Atlas (FDA). We then develop a two-step pipeline, BrIdge For Registering Over Statistical Templates (BIFROST), for transforming neural imaging data into this common space and for importing ex vivo resources such as connectomes. Using genetically labeled cell types as ground truth, we demonstrate registration with a precision of less than 10 microns. Overall, BIFROST provides a pipeline for registering functional imaging datasets in the fly, both within and across experiments. SignificanceLarge-scale functional imaging experiments in Drosophila have given us new insights into neural activity in various sensory and behavioral contexts. However, precisely registering volumetric images from different studies has proven challenging, limiting quantitative comparisons of data across experiments. Here, we address this limitation by developing BIFROST, a registration pipeline robust to differences across experimental setups and datasets. We benchmark this pipeline by genetically labeling cell types in the fly brain and demonstrate sub-10 micron registration precision, both across specimens and across laboratories. We further demonstrate accurate registration between in-vivo brain volumes and ultrastructural connectomes, enabling direct structure-function comparisons in future experiments.

neuroscience↗

bioRxiv2019

Effects of enalapril and paricalcitol treatment on diabetic nephropathy and renal expressions of TNF-α, P53, Caspase-3 and Bcl-2 in STZ-induced diabetic rats

This study aimed to assess the renopreventive effect of the angiotensin converting enzyme inhibitor (ACEI), enalapril, and/or vitamin D receptor (VDR) activator, paricalcitol, on streptozotocin (STZ) diabetes-induced nephropathy and to elucidate the mechanisms of action through investigation of the effects on renal oxidative stress, antioxidant defense system and expressions of TNF-, P53, caspase-3, and Bcl-2. Diabetes mellitus was induced in fasting male Wistar rats by single intraperitoneal injection of STZ (45 mg /kg b.w.) dissolved in citrate buffer pH 4.5. Ten days after STZ injection, the diabetic rats were treated with enalapril (25 mg/l of drinking water) and/or paricalcitol (8 {micro}g/kg b.w. per os) dissolved in 5% DMSO daily for 4 weeks. The obtained data revealed that the treatment of diabetic Wistar rats with enalapril and/or paricalcitol led to a significant decrease in the elevated serum urea, uric acid, creatinine and sodium, potassium levels; thereby reflecting improvement of the impaired kidney function. The deteriorated kidney lipid peroxidation, GSH content and GST and catalase activities in diabetic rats were significantly ameliorated as a result of treatment with enalapril and/or paricalcitol. The elevated fasting and post-prandial serum glucose levels and the lowered serum insulin and C-peptide levels were also improved. Moreover, the treatment of diabetic rats successfully prevented the diabetes-induced histopathological deleterious changes of kidney and islets of Langerhans of pancreas. In association, the immunohistochemically detected pro-inflammatory cytokine TNF- and apoptotic mediators P53 and caspase-3 were remarkably decreased in kidney of diabetic rats as a result of treatment, while the expression of anti-apoptotic protein Bcl-2 was increased. Based on these findings, it can be concluded that enalapril and paricalcitol can prevent STZ diabetes-induced nephropathy though amelioration of the glycemic state and antioxidant defense system together with the suppression of oxidative stress, inflammation and apoptosis.

pharmacology and toxicology↗

bioRxiv2017

Evolution of mechanisms that control mating in Drosophila males

Genetically wired neural mechanisms inhibit mating between species because even naive animals rarely mate with other species. These mechanisms can evolve through changes in expression or function of key genes in specific sensory pathways or central circuits. Gr32a is a gustatory chemoreceptor that, in D. melanogaster, is essential to inhibit interspecies courtship and sense quinine. Similar to D. melanogaster, D. simulans Gr32a is expressed in foreleg tarsi, sensorimotor appendages that inhibit interspecies courtship in both species, and it is required to sense quinine. Nevertheless, Gr32a is not required to inhibit interspecies mating by D. simulans males. However, and similar to its function in D. melanogaster, Ppk25, a member of the Pickpocket family, promotes conspecific courtship in D. simulans. Taken together, we have identified shared as well as distinct evolutionary solutions to chemosensory processing of tastants as well as cues that inhibit or promote courtship in two closely related Drosophila species.

neuroscience↗