-
Categories
-
Pharmaceutical Intermediates
-
Active Pharmaceutical Ingredients
-
Food Additives
- Industrial Coatings
- Agrochemicals
- Dyes and Pigments
- Surfactant
- Flavors and Fragrances
- Chemical Reagents
- Catalyst and Auxiliary
- Natural Products
- Inorganic Chemistry
-
Organic Chemistry
-
Biochemical Engineering
- Analytical Chemistry
- Cosmetic Ingredient
-
Pharmaceutical Intermediates
Promotion
ECHEMI Mall
Wholesale
Weekly Price
Exhibition
News
-
Trade Service
background component
Test Unique Unmatched Assay (TUNL)
- Before the test, male C57BL/6J mice entered the experiment when they were 10–18 weeks old, at which point they were housed individually
.
Rats had free access to water but were fed control (body weight maintained at 85-95% of baseline body weight)
.
, in a temperature-controlled environment (21 ± 1 °C) with a 12:12 light:dark cycle
. - Environmental adaptation training stage: the mouse must remember the presented stimulus image (1 white square stimulus), and make a choice, when the mouse accurately touches the white stimulus area, it disappears from the screen (after the stimulus appears in this stage, it is Unlimited time, the mouse will not disappear without touching it), the mouse can get 1 round food reward, and then the screen will automatically present the next stimulus During this period, the groove of the food feeding device will always light up with a yellow light (to prompt the reward occurrence), the memory of that location is quantified
. - Sample training phase: When the mouse gets at least 30 rewards after accurately touching the screen within 1h, it can enter the sample training phase: the mouse needs to select the white stimuli displayed on the black touch screen background, located randomly in the row and column matrix displayed location
.
Mice had to nose-poke the irritant to make it disappear from the screen
.
This is followed by a brief delay in duration (this time period is variable and controllable), usually in seconds, after which the stimulus automatically disappears after 20 seconds if the mouse does not touch the screen
.
When the mouse touches the stimulation area, it will be judged to be correct, and will receive a round particle reward, (at this stage, the groove for the food will only light up after the correct selection)
.
Initiating the next round of stimulation required the mouse to put its nose into the groove of the feeder to trigger it
. - TUNL test phase: When mice receive at least 30 rewards within 1h, they can enter the TUNL test phase, with 2 white stimuli presented on the touch screen: the previously presented sample stimulus and the new presented at a randomly selected location in the matrix.
stimulate
.
Mice must sniff new stimuli (i.
e.
stimuli not present in the sample phase) to receive a 1 pellet food reward
.
In each trial, the delay between the two stimuli was 2 seconds
.
If the mouse did not touch the previously presented sample stimuli within 10 seconds, it was judged as missed, and no new stimuli would appear, and it still started from the sample stimuli presented on the front line
.
When the mice reach the standard of 2-second delay learning and completion, they can continue to increase the difficulty of the experiment, randomly appear 2s, 4s and 8s delays in the experiment, manipulate the working memory through experiments, and manipulate sample stimuli and novel stimuli through experiments The distance between can detect mode separation
. - During the TUNL test, each trial started with the illumination of the chamber light and stimulus light
.
When mice nose-poked the food container located directly under the stimulus light, the stimulus light was turned off and the sample stimulus was randomly presented at one of ten locations in a 5×3 matrix on the touchscreen
.
When the mouse nose-pokes the irritant, it immediately disappears from the screen
.
After this, one of 3 delays (5, 10, 15 s) occurred
.
During the delay, the chamber light is on, the rear stimulation light is off, and nothing is displayed on the touchscreen
.
Delays were randomly selected in each trial
.
At the end of the delay, the rear stimulation light was illuminated to indicate that the selection phase could be initiated by nose poke of the food container
.
When the mice nose-poked the food container, the stimulus light was extinguished and the selection phase began
.
During the selection phase, two stimuli are presented on the screen simultaneously
.
The first is the sample stimulus (incorrect choice), which is presented in the same position as the sample stage presented
.
The second was a novel stimulus (the right choice), which was presented at random locations in a 5 × 3 matrix on the touchscreen
.
The horizontal and vertical distances between the sample stimuli and the novel stimuli varied randomly and independently on each trial
.
If the mouse sniffed the correct stimulus during the selection phase, 1 pellet of food was rewarded by giving the feeder
.
Provide a timeout by turning off the chamber light for 10 s if the mouse sniffs an incorrect stimulus during the selection phase
.
There was a 5-second trial interval after reward or timeout
.
The next trial starts after the trial interval
. - If necessary, a correction test can be added for the TUNL test
.
Specifically, if a wrong choice was made during the selection phase of a trial, the same stimulus pattern would appear on the next trial
.
This continues until the mouse makes the correct choice during the selection phase
.
This strategy is used to avoid the intractable side-biasing of the mouse, where all selections point to the right or left
.
In the KLIMBIC image setting interface, it is possible to perform the setting of continuously presenting the same image
.
To ensure that the mice were in a "task" state during the TUNL test, use 15 s after (1) presenting the sample stimulus, (2) lighting the stimulus light to indicate that the selection phase can be initiated, and (3) presenting the stimulus during the selection phase Hold in the middle
.
Specifically, at each time point during the trial, the trial was terminated if the mouse failed to poke the stimuli on the screen with the nose or initiate the selection phase by nose pokes on the food container within 15 s
.
Trials were terminated when mice completed 64 trials (excluding missed trials) or 60 minutes later, whichever occurred first
.
- There was no significant difference in the number of training sessions required to complete the training phase between C57BL/6J mice and DBA/2J mice
- C57BL/6J mice had significantly higher correct rates at 0, 5, and 10 s delay than DBA/2J mice (Fig.
3a)
.
The performance of C57BL/6J mice and DBA/2J mice was not significantly different on the 15-second delay
.
The largest difference between C57BL/6J and DBA/2J mice was 0 s latency, during which working memory had a negligible effect on performance
. - There was no difference in performance between C57BL/6J mice and DBA/2J mice when they were most discernible, during which the two alternative phase stimuli were shown at the widest distance
.
In contrast, DBA/2J mice showed significantly impaired performance on more difficult discrimination compared to C57BL/6J mice
- The performance of C57BL/6J mice and DBA/2J mice was equivalent at all latencies when the choice phase stimulus was presented at the widest horizontal distance (a, d)
.
Conversely, when the choice phase stimuli were presented at intermediate horizontal distances (b, e) and narrow horizontal distances (c, f), the performance of DBA/2J mice was significantly impaired relative to C57BL/6J mice
.
This performance impairment was observed across multiple latencies, most consistently at 0-second latency, when pattern separation rather than working memory was expected to explain the performance variation
.
This horizontal separation deficit (a vs.
d, b vs.
e, c vs.
f) was observed regardless of the vertical distance between the stimuli of the choice phase
.
