bioRxiv Science⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2025.02.10.637387

Investigating the Role of Onchocerca ochengi in Epilepsy Development: A Gerbil Model Study

Ayiseh, R. B.·Ulrick, A. F.·Etaka, J. C.·Dobgima, G. S.·Njobinkir, B. C.·Ghogomu, S. M.·Cho-Ngwa, F.
View original source ↗Export metadata ↓

Abstract

BackgroundOnchocerca volvulus infection is linked to onchocerciasis-associated epilepsy (OAE) in humans, but the role of Onchocerca ochengi in epilepsy development remains unexplored. This study aimed to investigate whether O. ochengi infection contributes to epilepsy development. Methodology/Principal FindingsGerbils were implanted with O. ochengi worm masses (test group) or underwent sham surgery (control group). Behavioral and physical assessments were performed between days 15-19 using multiple tests, including the elevated plus maze, open-field, object recognition, and hanging wire tests. On day 21, gerbils were sacrificed, and body/organ weights were recorded, along with worm mass survival. Implantation of 15 worm masses resulted in 100% mortality in the test group, while implantation of 10 worm masses resulted in 53.3% mortality, with all control animals surviving. At day 21, worm mass survival averaged 1.4 out of 10, with a viability score of 93.3%. Test animals showed significant reductions in body weight and increased spleen weight compared to controls, but no significant behavioral differences were observed. Conclusions/SignificanceWhile O. ochengi infection caused notable physical effects, including high mortality and changes in body/organ weights, no behavioral evidence of epilepsy was observed. The high mortality rate and limited observation period restrict the interpretation of these findings. Further studies with larger cohorts and longer observation periods are needed to assess the potential role of Onchocerca spp. in epilepsy development. To the best of our knowledge, this study represents the first attempt to establish an animal model for OAE. Author SummaryOnchocerca volvulus infection is linked to onchocerciasis-associated epilepsy (OAE) in humans, but we know less about whether other types of Onchocerca, such as Onchocerca ochengi, might also contribute to epilepsy. Our study aimed to investigate this question by infecting gerbils with O. ochengi worm masses and observing the impact on their behavior and physical health. We found that while the infection caused significant physical changes, including high mortality rates and changes in body and organ weights, there were no signs of behavioral changes typical of epilepsy. In particular, we did not see any of the usual neurological symptoms that might indicate epilepsy. These results suggest that while O. ochengi can affect animal health in some ways, it might not be directly involved in causing epilepsy. However, the high mortality rate in the infected gerbils and the relatively short duration of the study mean that we cannot draw firm conclusions. Future research with more animals and a longer time frame will be important to better understand whether Onchocerca worms contribute to epilepsy development in humans.

Explore related subjects

neurosciencePreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Ayiseh, R. B., Ulrick, A. F., Etaka, J. C., Dobgima, G. S., Njobinkir, B. C., Ghogomu, S. M., Cho-Ngwa, F.. 2025-02-12. Investigating the Role of Onchocerca ochengi in Epilepsy Development: A Gerbil Model Study. https://doi.org/10.1101/2025.02.10.637387

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Same Movements, Different Skills: How Context Shapes Learning in Humans and Neural Networks

What determines whether experiences are integrated into shared representations or split? Motor skill learning offers a revealing test: when two tasks require an identical sequence of movements, both intuition and theory suggest that practice in one should generalize to the other. Yet we find that changing context can make identical movements different skills. In simple recurrent networks trained on the same sequence across contexts, splitting was greatest when strong contextual inputs coincided with a high initial weight scale; neither alone sufficed. Greater representational separation coincided with separate context-specific learning curves. Humans practicing the same finger sequence while alternating between two performance-irrelevant contexts likewise exhibited context-specific curves, rather than the single continuous trajectory observed when practicing in a single context. State-space modeling favored split learning states in humans and very weakly coupled states in the most context-dependent networks. These findings have broader implications for understanding how learning generalizes across contexts.

neuroscience↗
bioRxiv2026

Postpartum resource scarcity reshapes maternal care, offspring prioritization, and the steroid-sensitive medial preoptic area

Parental care requires balancing offspring needs with environmental constraints, yet how resource scarcity alters the organization of maternal responses remains poorly understood. Here, we examined maternal behavior, offspring prioritization, and steroid receptor-associated extracellular matrix organization in postpartum rats exposed to limited bedding and nesting (LBN) or control conditions with ample nesting materials. LBN increased pup-directed and reduced self-directed behaviors but also increased behavioral entropy, a measure of behavioral fragmentation, indicating less predictable caregiving sequences. LBN dams preferentially retrieved male pups first, whereas control dams preferentially retrieved females first. LBN also increased the proportion of pup-investigation time directed toward males compared with controls. In offspring on postnatal day 10, corticosterone was elevated in female but not male LBN pups, a pattern that paralleled the maternal male bias. To identify associated neurobiological changes, we assessed steroid receptors and extracellular matrix organization in the medial preoptic area (mPOA), a key region for maternal behavior. LBN increased numbers of estrogen receptor (ER)- and androgen receptor (AR)-immunoreactive cells, reduced perineuronal net (PNN) abundance, and decreased receptor-positive cell enwrapment. Because PNNs constrain structural plasticity, these findings suggest that the postpartum environment alters the organization of steroid receptor-associated extracellular matrix, potentially modulating experience-dependent plasticity in neurosteroid-sensitive circuits. In sum, LBN increases the levels of maternal engagement while reshaping its temporal organization and allocation, accompanied by selective remodeling of steroid-sensitive preoptic architecture. Therefore, maternal adaptation to adversity may be better understood as changes in caregiving allocation strategies rather than a simple gain or loss of maternal care.

neuroscience↗
bioRxiv2026

The Computational Grammar of Human Behaviour in a Biological Environment

Human behaviour unfolds as an extended stream of spontaneous actions shaped by environmental demands and the agent's goals. The organisation of these actions, situated between setting abstract goals and concrete movement execution, remains poorly characterised. Here, we introduce DynaClade, an unsupervised temporal action segmentation algorithm for human full-body motion capture data, and apply it to freely moving participants navigating ecologically realistic risky foraging environments in virtual reality. DynaClade identifies discrete actions whose kinematic characteristics and spatial distributions correspond to environmental affordances, supporting the validity of the approach. Among these actions, we discovered a hitherto undescribed movement pattern defined by increased body sway without locomotion. Action sequences were highly non-random and showed clear history dependence beyond first-order Markov structure, most of which was explained by a second-order prediction. This higher-order structure was well captured in a hidden Markov model, in which some of the observed actions were associated with more than one latent state. Each of these latent states corresponded to the same action in a distinct action context. These findings suggest that spontaneous human actions are predominantly selected based on the current action and context, rather than following pre-planned or habitually assembled sequences.

neuroscience↗