Biology subjects

Matak, I.

Publications and source records attributed to Matak, I..

2 recordsLinked to original sources

bioRxiv2024

Experimental parkinsonism induced by tetanus toxin injected into basal ganglia

Background and ObjectivesLocal inhibitory circuits and long-range inhibitory projections within the interconnected basal ganglia nuclei are critical for control of voluntary movement and pathophysiology of different extrapyramidal movement disorders. Herein, we examined the major motor effects of tetanus neurotoxin (TeNT), a presynaptic neurotoxin that selectively targets the GABA-ergic synaptic transmission, when injected into individual basal ganglia nuclei. MethodsThe rats were injected with low-dose TeNT (0.4-0.8 ng) unilaterally into globus pallidus internus (GPi), substantia nigra (SN), or caudate putamen (CPu). The effects of TeNT-induced disinhibition were characterized by repeated assessments of motor coordination, gait, and rotational behavior, followed by measurement of regional protein content of major neuronal monoaminergic, GABA-ergic and glutamatergic population markers. ResultsIn the beamwalk test, the CPu injection of TeNT induced contralateral plantar misplacement. TeNT injections into GPi and CPu were associated with decreased stride length and increased duration of step cycle and induced a slight ipsiversive circling during open field observation, and more intensive rotational behavior during swimming, differentially affected by D-amphetamine. Unlike rotational behavior, the gait and motor control deficits during beamwalk recovered promptly by day 14 post TeNT, which, along with the lack of reduced neuronal marker protein contents, suggested the reversibility and lack of neuronal degeneration. Conclusion and ImplicationsTetanus toxin injected into basal ganglia evokes transient hypokinetic motor dysfunctions consistent with experimental parkinsonism, with differential occurrence of individual motor symptoms depending on the region targeted. These results suggest that TeNT might be a useful non-neurodegenerative pharmacological agent for investigating the motor control abnormalities involving GABA-ergic basal ganglia circuits.

pharmacology and toxicology↗

bioRxiv2020

griPASTA: A hacked kitchen scale for quantification of grip strength in rodents

Assessment of neuromuscular function is critical for understanding pathophysiological changes related to motor system dysfunction in many rodent disease models. Among methods used for quantification of grip performance in rodents, gauge-based grip strength meters provide the most reliable results, however, such instruments are unaffordable by many laboratories. Here we demonstrate how to build a rodent grip strength apparatus from scratch using a digital kitchen scale, an empty cage, and a microcontroller, with both hardware and software being completely open-source to enable maximal modularity and flexibility of the instrument in concordance with the principles of open-source bioinstrumentation. Furthermore, we test the griPASTA system for assessment of increased muscular rigidity in the proof-of-concept experiment in the rat model of Parkinsons disease induced by intrastriatal administration of 6-hydroxydopamine (6-OHDA). Finally, the importance of bioinstrumental customization is demonstrated by utilizing griPASTA for assessment of trial speed from initial-to-maximal deflection time segments and controlling for its potential confounding effects on the grip strength. Significance StatementNeuromuscular function analyzed by grip strength performance tests is an integral part of motor system neuroscience and neurotoxicology. Strain gauge-based grip strength meters provide the most reliable results, however, commercial solutions are unaffordable by many. Consequently, cheap semi-quantitative tests are often used at the expense of precision and reliability. We propose griPASTA - a simple and robust open-source grip strength platform made from an ordinary kitchen scale. griPASTA could improve the quality and reproducibility of grip strength experiments by enabling researchers to obtain quantitative grip strength data in high resolution using a highly customizable platform.

neuroscience↗