Nowadays besides using conventional mammal species, the zebrafish has became an equally important laboratory animal. Apart from its intensively popular cardiovascular usage, this species can also be efficiently used for neural and psycho-physiological/pharmacological basic- and applied researches. To enable such applications, our firm developed the PSYCHOFISH measuring system. This system is suitable for quantitative monitoring single individual motion and group behaviour.
The system, which was developed for monitoring the group cohesion (social interaction) and movement intensity (loco motor activity) of the zebra fish, consists of the next three main units:
- Mechanical unit
- Image recording unit
- Hardware/software allows storing, visualizing and evaluating the image sequence
While designing the system, we focused on its ability to be easily assembled. On the grounds of this, a workstation was created, which ensure easy learnability and usability of the system.
A 1260x500x1250mm anodized aluminium frame is providing the basis of the mechanical unit, which includes the pool-holding plate. This plate is made of white opal Plexiglas to provide an even light-distribution. The power supply unit, which insures the power supply of the lighting, is placed inside the frame.
The system provides a possibility for two different arrangements of lighting, which allows a wider range of methodical application:
- Lower light intensity with white background lighting
- Upper infra lighting
The infra lighting and the image recording unit are positioned on the horizontal level of the vertical aluminium frame. Both components can be adjusted on its own level. On the pool holding plate optimally 4 pieces of 100x200x50 mm fish pools can be placed.
The KOMI image evaluating program, belonging to the measurement systems, is made for the objective monitoring of group cohesion (social interaction) and movement intensity (locomotor activity) of the zebra fish. It provides an opportunity to process and evaluate previously recorded (image sequences). The two different measurement procedures are controlled by two different programme branches.
Examining group cohesion (social interaction)
When measuring the social interaction of offspring, one has to take into consideration the space need, water depth, entity- and group sizes, which are necessary for analysing the normal behaviour of the zebra fish. Owing to that, the fish are examined in a 20mm water depth. During the measurements, a digital video recording is made of the movement of the entities, which is processed by the Komi programme branch. This software function is available through the related icons.
After entering the programme the main screen shows up with the recorded image sequence. The recording can be calibrated by means of the controlling panel on the right side of the screen, as well as setting the exact length of the pool and the number of fish.
The software automatically performs the graphical and numerical processing of the video recording, while it also determines distance and area values. During the evaluation, the software identifies the position of the fish, and marks them with white crosses. The number of recognized fish appears on the screen, and the alteration of the area of the polygon (one of the index-number of the group cohesion, that contains the shoal, can be monitored, while the orbit line of the geometrical midline of the group stands out).
During the processing, the calculated data is gathers into an Excel table:
- Area of the bounding polygon
- Longest diagonal of the bounding polygon
- Coordinates of the centre of gravity of the bounding polygon (compared to the middle of the pot)
- Distance of the centre of gravity of the bounding polygon from a reference point.
- Distances averaged to all the fish: distances measured from the closest fish, distance measured from the farthest fish, and distance measured from all the other fish.
- Average of the distance of all the fish pairs.
Examining movement intensity (locomotor activity)
When measuring loco motor activity of offspring, one has to take into consideration the space need, water depth, that are necessary for the normal behaviour of the zebra fish. Owing to that, the fish are examined in a 20mm water depth, in maximum 4 pools. During the measurements, a digital video recording is made of the movement of the entities, which is processed by the KomiM programme branch. This software function is available through the related icons.
After entering the programme the main screen shows up with the recorded image sequence. The recording can be calibrated by means of the controlling panel on the right side of the screen, as well as setting the exact length and partition of the pools and the number of fish.
Taking these parameters into account, the software automatically performs the graphical and numerical processing of the video recording. The programme automatically identifies the position of the fish, and marks them (with colourful crosses). The number of recognized fish appears, and the orbit line of their movement stands out. Moreover the movement speed and the length of the covered distance of all the fish is calculated. All data are collected in an Excel table.
|Overall dimension:||1260x500x1250 mm|
|ze of pool holder plate:||450x350 mm|
|Material of pool holder plate:||
|Size of the pool:||200x100x50 mm|
|Material of the pool:||glass|
Height of camera holder:
|maximum 900 mm (adjustable)|
|Lower lighting:||12V DC/25W|
|Infra lighting:||12V DC/8W|
|monochrome DMK 23G274 HF 12.5 with optics|
How can it help?
The PsychoFish measuring system was developed and manufactured by our company to test behavioral patterns on adult (3 months old) and juvenile (1-2 months old) species. The developed measurement system is a highly integrated workstation, which contains mechanics, optics and a data display-, storage- and evaluating-software. The product was designed to test two fundamental group behaviors, the analogies of which can also be found in human behavior patterns:
- Social interaction
- Locomotor activity
The measuring system is based on the zebrafish (Danio rerio or Brachydanio rerio) model. The selection of the species was influenced by the fact that social life is regarded to be highly widespread among fish, as well as that lifelong group formation is the characteristic of a quarter of fish species (zebrafish belongs to this quarter).
In the zebrafish research social behavior primarily means group formation, the social attraction and the regulation of distancing from peer. The importance of this is not so much the topic of biological curiosity, but the fact that a phenomenon which is relatively easy to examine (social attraction to peers ), fish serve as a well-testable model even to human physiological, genetic and neurological research. Zebrafish became a popular experimental animal because of their relatively simple nervous system, well- known genome, and last but not least the strict animal welfare regulation of the different invasive and lethal interventions. To test group formation, in recent years a method has been developed, which combines the easily-manipulated fish behavior with a high degree of automation of data collection and analysis. Neurological researches carried out on the species are also significant, such as lateralization (the research of such neurological and neuroethological phenomena, which show a characteristic left-right separation on the expression level) (Halpern et al. 2003).
Neurophysiology techniques (the definition of quantity of certain neurotransmitters after the removal of the brain of the fish) revealed interesting relationships between the timing of group formation and the amount of certain neurological mediating materials. It turned out that in case of the Danio rerio, they are primarily the dopamine and dopamine-like neurotransmitters, which show a similar increasing production during ontogenesis, as well as an increasing tendency to form groups (Buske and Gerla, 2012). However, group formation tendency ceases in case of adult fish treated with dopamine D1 receptor blocking drug (vision and mobility, as well as other behaviors remain intact (Scerbina et al. 2012)). The relationship between dopamine system and social behavior was confirmed by the discovery, which was based on the differences found in the zebrafish lines. It turned out that the in case of phylum coded ' AB ', group formation tendency continues to grow during ontogenesis, while there is a sudden change in case of phylum coded ' TU ' between the ages of 25 and 50 days. Investigating the presence of neurotransmitters in the brain of the fish in the questioned period it turned out that while dopamine dopamine concentration shows a linear increase in case of phylum coded ' AB ', the dopamine level increases shows a sudden increase in case of phylum coded ' TU ' during the development of the species (Scerbina et al., 2012).
Unique technical solutions supporting the measurement
The mechanical and the imaging elements of the measuring system can be used in both studies (social interaction and locomotor activity).
The system, which is capable of measuring the social interaction and locomotor activity of the fish offspring takes into account the space and water depth requirements required for normal behavior, and the species and group sizes.
Examination pools with white background bottom lighting and top infrared lighting allows a wider range of methodological application. Any selected mechanism allows glint-free lighting. As a result of that the movement of the fish can be easily followed.
The background of the examinations is provided by the two branches of the KOMI software. In both cases the software uses the same algorithm to handle sequences capture, display, but there are substantial differences in the analysis.
This means that the user can quickly learn the necessary management skills and the purchasing costs of the necessary testing equipments are also reduced.
Other potential applications
An essential assistance to obtain further information is that dopamine-like transmitters, which trigger action, can also be examined in vitro. Our company can offer the ISN-01 release superfusion system to conduct the investigation.
An integral part of our company philosophy is to continuously follow-up the sold products, provide fast service and methodological trainings. Trainings can be organized in the following place:
|Szent Istvan University, Department of Aquaculture||Gödöllő, HUNGARY||Béla Urbányi, PhD|
You find details by clicking on the product code.
ZFS-02-02 Locomotor activity measurements add-on module for ZFS-02 PsychoFish system
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