Animal muscle physiological function detection system

Animal muscle physiological function detection systemAt present, three different experimental methods (in vivo/in situ/ex vivo) are used to measure the muscle function and mechanical properties of rats and mice, measure the parameters of force length velocity, and explore the relationship between these parameters, as well as the reasons behind the relationship. Combining three different experiments is to meet different needs. Although traditional ex vivo experiments can be performed on a wide range of muscle types, all muscles are in an ex vivo artificial environment, and some thick and complex tendon structures are not suitable for ex vivo experiments and can be performed in situ. In vivo experiments are a type of functional expression that can express muscle function measured in physiological environments and have continuity.

Advantages:

1. Time and effort saving,Animal muscle physiological function detection systemAlthough it is applied to three different types of experiments, you only need to learn one set of hardware and one set of software. When you want to switch between experimental types, the replacement of accessories involved is very simple and precise. For example, converting a bathtub used for ex vivo experiments to an animal platform used for in situ or in vivo experiments only requires adjusting a few screws, and the process does not take more than 5 minutes.

2. Save money. The design of the system device is based on the three types of experiments mentioned above, each with different experimental plans that can be carried out. For example, in vitro experiments can be conducted with measurements such as equal length contraction tension, elongation contraction, fatigue, and the relationship between force and stimulus frequency. There are many things that can be done with the three different types of experiments combined. Therefore, the cost-effectiveness of the system is high, and a single system can perform multiple experimental plans.

3. We all know that every research topic will generate a lot of questions and doubts, and no single experiment or method can provide all the answers. Why does this system actually combine these three types of experiments together? It is because each experiment provides a complementary answer to another experiment, which allows you to have a more complete puzzle of the animals being tested.

Application fields

Muscle Physiology/Pathologist: Research the mechanism of muscle contraction, the influencing factors/channels of different mechanical properties of muscles, and use muscle disease models (such as those with muscle atrophy, muscle pain, spinal cord injury, etc.) to study the pathology of different muscle diseases. Study the mechanisms of onset, injury, fatigue, recovery, etc., and measure changes in muscle function before and after drug or gene therapy.

Some other examples:

Metabolist and Cardiologist: This system can be used to study the functional disorders caused by metabolism, such as diabetes

Sports scientist: Exploring how to optimize muscle function

Bioengineers: Can test the effectiveness of biomaterials and implants that improve muscle function

Geneticists and pharmacologists: can be used to test the efficacy of genetically modified or gene knockout mice after gene therapy, and used for drug screening

Neurologist: Can be used to study changes in electromyography (EMG) during muscle contraction

Biologists and biochemists: used to identify basic indicators of muscle function

Gerontology: Testing the effects of aging on muscle function, continuous in vivo experiments are of great help in this field

Principle:

In vivo experiments:

It mainly measures the torque generated by ankle flexion through plantar and dorsiflexion. The software, stimulator, dual-mode sensor, animal platform, and the first two experiments used for in vivo testing are the same. *The difference is that the cantilever connected to the dual-mode sensor needs to be replaced with a foot cover.

The animal is first anesthetized, then placed on an animal platform, and its feet are tied together with ankle cuffs. Finally, electrode needles are used to provide electrical stimulation to the muscle group through specific muscle nerves, and the entire process does not involve any surgical procedures.

In terms of electrical stimulation, which muscle groups will be stimulated depends on which nerves we stimulate. Generally speaking, stimulating the pulmonary nerve and total pulmonary nerve will induce dorsiflexion (tibialis anterior muscle and extensor digitorum longus muscle), while stimulating the sciatic nerve will induce plantarflexion (gastrocnemius muscle, soleus muscle).

After connecting your feet to the experimental device, you can complete the entire experiment through the operation of our software system. Based on only connecting one tendon, different contractions and measurements can be performed (such as centrifugal contraction, centripetal contraction, isometric contraction, etc.), fully describing the mechanical properties of the muscle strip.

In situ experiment:

In situ experiments are used to measure individual muscles or muscle groups, as one end of the muscle is connected to the animal's body and can remain active in physiological environments. Meanwhile, the software, stimulator, dual-mode sensor, and ex vivo system used in the in-situ testing system are the same. *The difference lies in the hardware aspect of the experimental setup, where the detached bathtub will be replaced with a controllable temperature platform.

On this platform, animals will be anesthetized first and then placed on the platform. The target leg will be fixed in the appropriate position using our customized clamp, and one end of the tendon will be connected to the cantilever of the dual-mode sensor using a line. Finally, two electrode needles will be used to stimulate the muscle nerves or directly provide electrical stimulation to the muscle.

After connecting the muscle strip to the experimental device, you can complete the entire experiment through the operation of our software system. Based on only connecting one tendon, different contractions and measurements can be performed (such as centrifugal contraction, centripetal contraction, isometric contraction, etc.), fully describing the mechanical properties of the muscle strip.

In vitro experiment:

Extract a single muscle through surgical procedures and place it in a bathtubPlace the muscle strips in a vertical bath bottle, which is filled with nutrient solution and continuously oxygenated. One end of the muscle tendon is connected to a fixed position, and the other end is connected to a cantilever of a dual-mode sensor. A dual-mode sensor allows you to simultaneously measure and control both force and length parameters while only connecting one end of the tendon.

After connecting the muscle strip to the experimental device, you can complete the entire experiment through the operation of our software system. Based on only connecting one tendon, different contractions and measurements can be performed (such as centrifugal contraction, centripetal contraction, isometric contraction, etc.), fully describing the mechanical properties of the muscle strip.

The core device of the 305C-FP series is a dual-mode sensor:

The meaning of dual-mode is that it is not only a force sensor, but also has the function of a position sensor. In addition to measuring both force and position (muscle tension and length changes) simultaneously, dual-mode sensors also have the ability to control force and length.

In this regard, dual-mode sensors can be considered very rare because they can simultaneously measure and control two parameters. Therefore, only one connection point is needed between the sensor and the sample, which means that only one end of the muscle tendon needs to be connected. This is very important, and the experimental steps are simpler and the time is shorter. This is also the reason for conducting both in situ and in vivo experiments.

Because dual-mode sensors are not only force sensors, but also have the function of position sensors, there are also a wider range of experimental schemes that can be performed in measurement: in addition to traditional schemes such as simple equal length twitching, rigid contraction, fatigue, tension stimulation frequency, etc., they can also perform centrifugal contraction, isobaric contraction, centripetal contraction, etc., as well as the relationship between force and contraction rate, etc