Biology subjects

Desta, T.

Publications and source records attributed to Desta, T..

4 recordsLinked to original sources

bioRxiv2024

Trypanosome infection rate and blood-feeding patterns of tsetse fly in an area with a recent human African trypanosomiasis outbreak in Southwest Ethiopia

IntroductionThe recent outbreak of Human African Trypanosomiasis (HAT) in the Deme River Valley, Ethiopia, has highlighted the need for more comprehensive data on the infection rate of trypanosomes and the feeding patterns of tsetse. The study aimed to assess the infection rate of trypanosomes and the feeding patterns of tsetse flies collected using various attractants. Methodology/principal findingsTraps with various bait odors were placed randomly and rotated monthly. Anesthetized and recently deceased tsetse flies were examined to determine the infection rate using microscopy, and the origins of the blood meal were determined using the polymerase chain reaction technique. We used the Poisson regression model to analyze count data and the binary logistic regression model to assess binary outcomes (positive or negative) and infection rates. Of the 1208 tsetse flies captured, 751 (62.2%) were Glossina pallidipes, while 457 (37.8%) were Glossina fuscipes fuscipes. The trypanosome infection rate in tsetse flies was 17.1% (95% CI: 14.2-20.3). Of the 103 positive tsetse flies, 66% were infected with T. congolense, 24.3% with T. vivax, 1.9% with T. brucei, and 7.8% with either T. congolense or T. brucei (the immature stages identified in the mid-gut). The infection rate of trypanosomes in G. pallidipes (19. 6%) was higher than that of G. f. fuscipes (12.8%). Traps using a combination of cow urine and acetone captured tsetse flies with a higher infection rate of trypanosomes (21.2%), followed by acetone alone (18.9%), cow urine alone (12.2%), and traps without bait (6.1%). Of 107 freshly fed tsetse flies, 23.4% were fed to dogs, 8.4% to humans, 7.5% to cattle, and 4.7% to goats, including the mixed blood meals. Conclusions/main suggestionsThe high trypanosome infection rate in tsetse flies indicates an increased risk of trypanosomiasis infection. Although tsetse flies seem attracted to dogs, the potential risk of human exposure must also be considered. Further research is needed to understand the role of dogs in parasite transmission. Authors summaryAfrican Animal Trypanosomosis (AAT) is a significant issue in animal production in sub-Saharan African countries, including Ethiopia. The recent outbreak of HAT in the Deme River Valley, Ethiopia, has emphasized the need for more comprehensive data on the infection rate of trypanosomes and the feeding patterns of tsetse flies to understand human exposure. The current study revealed a high infection rate of trypanosomes in tsetse flies, with T. congolense having the highest prevalence, followed by T. vivax. Public concern is related to the T. brucei complex, as it is possibly the strain that causes HAT. Combining cow urine with acetone could significantly improve tsetse trapping and be used in tsetse suppression programs to reduce the risks of infectious tsetse flies. Analysis of the blood meal origins revealed that tsetse flies feed on various vertebrate animals, including dogs and humans. Urgent research is needed to understand the role of dogs in parasite transmission. It is recommended that large-scale tsetse control be implemented using baits such as fermented cow urine in combination with acetone for tsetse suppression.

zoology↗

bioRxiv2020

Human cortical expansion involves diversification and specialization of supragranular intratelencephalic-projecting neurons

The neocortex is disproportionately expanded in human compared to mouse, both in its total volume relative to subcortical structures and in the proportion occupied by supragranular layers that selectively make connections within the cortex and other telencephalic structures. Single-cell transcriptomic analyses of human and mouse cortex show an increased diversity of glutamatergic neuron types in supragranular cortex in human and pronounced gradients as a function of cortical depth. To probe the functional and anatomical correlates of this transcriptomic diversity, we describe a robust Patch-seq platform using neurosurgically-resected human tissues. We characterize the morphological and physiological properties of five transcriptomically defined human glutamatergic supragranular neuron types. Three of these types have properties that are specialized compared to the more homogeneous properties of transcriptomically defined homologous mouse neuron types. The two remaining supragranular neuron types, located exclusively in deep layer 3, do not have clear mouse homologues in supragranular cortex but are transcriptionally most similar to deep layer mouse intratelencephalic-projecting neuron types. Furthermore, we reveal the transcriptomic types in deep layer 3 that express high levels of non-phosphorylated heavy chain neurofilament protein that label long-range neurons known to be selectively depleted in Alzheimers disease. Together, these results demonstrate the power of transcriptomic cell type classification, provide a mechanistic underpinning for increased complexity of cortical function in human cortical evolution, and implicate discrete transcriptomic cell types as selectively vulnerable in disease.

neuroscience↗

bioRxiv2020

Toward an integrated classification of neuronal cell types: morphoelectric and transcriptomic characterization of individual GABAergic cortical neurons

Neurons are frequently classified into distinct groups or cell types on the basis of structural, physiological, or genetic attributes. To better constrain the definition of neuronal cell types, we characterized the transcriptomes and intrinsic physiological properties of over 3,700 GABAergic mouse visual cortical neurons and reconstructed the local morphologies of 350 of those neurons. We found that most transcriptomic types (t-types) occupy specific laminar positions within mouse visual cortex, and many of those t-types exhibit consistent electrophysiological and morphological features. We observed that these properties could vary continuously between t-types, which limited the ability to predict specific t-types from other data modalities. Despite that, the data support the presence of at least 20 interneuron met-types that have congruent morphological, electrophysiological, and transcriptomic properties. HighlightsO_LIPatch-seq data obtained from >3,700 GABAergic cortical interneurons C_LIO_LIComprehensive characterization of morpho-electric features of transcriptomic types C_LIO_LI20 interneuron met-types that have congruent properties across data modalities C_LIO_LIDifferent Sst met-types preferentially innervate different cortical layers C_LI

neuroscience↗

bioRxiv2018

Classification of electrophysiological and morphological types in mouse visual cortex

Understanding the diversity of cell types in the brain has been an enduring challenge and requires detailed characterization of individual neurons in multiple dimensions. To profile morpho-electric properties of mammalian neurons systematically, we established a single cell characterization pipeline using standardized patch clamp recordings in brain slices and biocytin-based neuronal reconstructions. We built a publicly-accessible online database, the Allen Cell Types Database, to display these data sets. Intrinsic physiological and morphological properties were measured from over 1,800 neurons from the adult laboratory mouse visual cortex. Quantitative features were used to classify neurons into distinct types using unsupervised methods. We establish a taxonomy of morphologically- and electrophysiologically-defined cell types for this region of cortex with 17 e-types and 35 m-types, as well as an initial correspondence with previously-defined transcriptomic cell types using the same transgenic mouse lines.

neuroscience↗