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Advanced Neurology Voluntary running effects in PTEN knockout mouse

Pten /Nse-Cre , Pten loxP/+ /Nse-Cre , - or Pten loxP/loxP / 2.2.3. Social behavior
+
+/+
Nse-Cre were considered wild-type (WT, PTEN ) since The social interaction test measures the integration between
-
+/+
they present a regular PTEN expression. individuals of the same species in the same environment for
[38]
Females of the Pten loxp/+ /Nse-Cre lineage were divided a certain period . Following the protocol by Nadler et al. ,
[37]
+
into four groups: WT sedentary (WTS), HT sedentary a box measuring 20 cm × 40.5 cm × 22 cm was used, with two
(HTS), WT exercise (WTE), and HT exercise (HTE). The partitions placed to form three chambers: one central and
voluntary physical exercise protocol involved providing two laterals. This division was made using two transparent
[31]
a rotating wheel inside the mouse home cage, allowing the plates with a 3.5 cm diameter opening, allowing the animals
mice to engage involuntary physical exercise for 10 days. to move from one chamber to another. Sociability was
Before starting the experimental procedure, the mice were measured in the first phase of the test. In the first phase, the
evaluated for 96 h to verify their motivation to walk on test mouse was placed in the center of the box for 5 min for
the wheels. An apparatus that detects the number of wheel habituation. After that, the test mouse was removed, and two
turns was used when the animals were in the cage. The grid cages were added to the lateral chambers of the box: An
body mass and food intake of each female were evaluated empty cage and another containing a non-familiar mouse
weekly throughout the experimental period. After 10 days (the non-familiar animal was previously habituated to the
of physical exercise, behavioral tests were performed, apparatus), which had not interacted previously with the test
starting with the open field test, followed by the elevated animal. The test mouse was then placed back in the center of
plus maze, social behavior, and passive avoidance tests. The the apparatus, and the time spent exploring the “empty” side
time interval between the behavior tests was 24 h. One day or the non-familiar mouse was measured. This observation
after the last behavior test, the mice were euthanized, and period lasted for 10 min. After each mouse, the apparatus was
the cerebral cortex was dissected and kept frozen at −80°C cleaned using 5% alcohol, and the arrangement of the empty
until protein extraction for western blotting assay. object with the one containing the non-familiar mouse
was alternated. The social novelty or social recognition
2.2. Behavioral tasks memory phase was conducted 10 min later. In this phase,
the previously encountered non-familiar mouse was placed
All behavioral tasks were recorded using a video camera on one of the sides of the apparatus, while a novel animal,
connected to a computerized digital system controlled which had been previously habituated to the apparatus but
through the software Anymaze (Stoelting. IL, USA).
®
had no prior contact with the test mouse, was placed on the
2.2.1. Open field other side. The time spent exploring the familiar or the novel
mouse was then measured, with observations conducted for
Following the methodology described by Kawamoto 10 min. After each mouse’s observation, the apparatus was
et al. , mice were positioned in the center of a 40 cm × cleaned using 5% alcohol.
[35]
40 cm open field apparatus, and their time spent in the
center or the periphery of the apparatus was recorded for 2.2.4. Passive avoidance
10 min. The main objective of this test was to evaluate The passive avoidance apparatus (Insight, São Paulo,
the preservation of the animal’s locomotor activity and Brazil) is a device composed of two same-sized chambers,
anxiety-like behavior, using the amount of time the animal one clear and the other dark, separated by an automatic
remained in the center or the periphery of the apparatus. door. The floor of the compartments was made of stainless-
2.2.2. Elevated plus maze steel rods, and only the dark chamber floor was electrified.
On the 1 day (exposure session), each mouse was placed
st
To evaluate anxiety-like behavior, we used an elevated in the clear chamber, and the automatic door was opened.
plus maze based on Texel et al. , with modifications. The Once the mouse entered the dark compartment, the door
[36]
maze used was a cross-shaped wooden apparatus with was closed, and the mouse received an electric foot shock
arms measuring 25 cm × 5 cm, elevated by a 60 cm holder. (0.5 mA, 2 s in duration) through the grid floor. Immediately
Two opposite arms were enclosed by a 20 cm wall, while after the shock, the mouse was removed from the dark
the other two arms were left open. Mice were individually compartment and returned to its home cage. After 24 h,
placed at the center of the maze, facing one of the closed the mouse was subjected to the test (probe session), and
arms. Their movements within the maze were observed the measurement of fear-motivated memory was obtained
for 5 min. The exploration profile regarding the areas of from the latency to move to the dark compartment. Mice
the apparatus (open and closed arms) was analyzed, with a that failed to enter the dark compartment within 5 min
particular focus on the profile of open-arm exploration to were removed from the apparatus and assigned a ceiling
assess anxiety-like behavior. score of 300 s .
[39]

Volume 2 Issue 3 (2023) 3 https://doi.org/10.36922/an.0872