Biology subjects

Uyanik, I.

Publications and source records attributed to Uyanik, I..

4 recordsLinked to original sources

bioRxiv2023

The Effects of Flow Speeds on Smooth Pursuit Tracking and Active Sensing Movements of Weakly Electric Fish

Weakly electric fish employ refuge-tracking behavior to survive, seeking and utilizing hiding places to shield themselves from predators and unfavorable environmental conditions. This adaptive mechanism enables them to minimize the risk of predation, maintain optimal electrocommunication, and adapt to changing surroundings. While studies have explored smooth pursuit tracking and active sensing movements of these fish in stationary environments, limited emphasis has been given to how varying flow speeds in their natural habitats may impact these behaviors. This study addresses this gap by investigating the effects of different flow speeds on smooth pursuit tracking and active sensing movements in weakly electric fish. Active sensing provides sensory data and multisensory integration processes and combines this data to create a holistic perception of the environment. The synergy between these processes is fundamental for enhancing an organisms sensory capabilities and enabling it to adapt and interact effectively with its surroundings. For this study, a specialized experimental setup was designed and built to facilitate refuge-tracking behavior under controlled flow conditions. The experiments involved Apteronotus albifrons fish exposed to visual and complex electrosensory stimuli, which consisted of a sum of sine signals. Data was recorded for different sensory conditions, including variations in flow speeds, illumination levels, and refuge structures. The analysis revealed that increased flow speeds correlated with reduced tracking gain and phase lag in the fish. Additionally, it was observed that active sensing movements were more pronounced in dark conditions. These findings highlight the significant impact of flow speeds on smooth pursuit tracking and active sensing movements and emphasize the importance of studying these behaviors within the context of water flow. Understanding the biological motivations underlying these effects is vital for their potential application in engineering fields.

animal behavior and cognition↗

bioRxiv2023

Predictive Uncertainty in State-Estimation Drives Active Sensing in Weakly Electric Fish

Animals use active sensing movements to shape the spatiotemporal characteristics of sensory signals to better perceive their environment under varying conditions. However, the underlying mechanisms governing the generation of active sensing movements are not known. To address this, we investigated the role of active sensing movements in the refuge tracking behavior of Eigenmannia virescens, a species of weakly electric fish. These fish track the longitudinal movements of a refuge in which they hide by swimming back and forth in a single linear dimension. During refuge tracking, Eigenmannia exhibits stereotyped whole-body oscillations when the quality of the sensory signals degrades. We developed a feedback control model to examine the role of these ancillary movements on the task performance. Here, we show that the proposed model generates fish trajectories that are statistically indistinguishable from the actual fish, implying that active sensing movements are regulated to minimize the predictive uncertainty in state estimation.

animal behavior and cognition↗

bioRxiv2020

Knockout of zebrafish desmin genes does not cause skeletal muscle degeneration but alters calcium flux

Desmin is a muscle-specific intermediate filament protein that has fundamental role in muscle structure and force transmission. Whereas human desmin protein is encoded by a single gene, two desmin paralogs (desma and desmb) exist in zebrafish. Desma and desmb show differential spatiotemporal expression during zebrafish embryonic and larval development, being similarly expressed in skeletal muscle until hatching, after which expression of desmb shifts to gut smooth muscle. We generated knockout (KO) mutant lines carrying loss-of-function mutations for each gene by using CRISPR/Cas9. Mutants are viable and fertile, and lack obvious skeletal muscle, heart or intestinal defects. In contrast to morphants, knockout of each gene did not cause any overt muscular phenotype, but did alter calcium flux in myofibres. These results point to a possible compensation mechanism in these mutant lines generated by targeting nonsense mutations to the first coding exon.

developmental biology↗

bioRxiv2019

Variability in locomotor dynamics reveals the critical role of feedback in task control

Animals vary considerably in size, shape, and physiological features across individuals, but yet achieve behavioral performances that are virtually indistinguishable between conspecifics. We examined how animals compensate for morphophysiological variation by measuring the system dynamics of individual knifefish (Eigenmannia virescens) in a refuge tracking task. Kinematic measurements of Eigenmannia were used to generate individualized estimates of each fishs locomotor plant and controller revealing substantial variability between fish. To test the impact of this variability on behavioral performance, these models were used to perform simulated brain transplants--computationally swapping controllers and plants between individuals. We found that simulated closed-loop performance was robust to mismatch between plant and controller. This suggests that animals rely on feedback rather than precisely tuned neural controllers to compensate for morphophysiological variability.

neuroscience↗