Our experimental closed head injury paradigm followed procedures previously
described (Mouzon et al.,
2012 ). Procedures have been described in detail in Ojo et al., 2018 (link).
Briefly, we anesthetized sham/injury mice for 3 min with 1.5 L/min of oxygen and
3% isoflurane. We shaved the head of mice and placed them on a stereotaxic frame
(Just For Mice Stereotaxic, Stoelting, Wood Dale, IL) that was mounted with an
electromagnetic controlled impact device (Impact One Stereotaxic Motorized
Impactor, Richmond, IL). Their body temperature was maintained at 37°C on a
heating pad. A flat and blunt 5-mm metal impactor tip mounted onto the
electromagnetic motorized device was zeroed on the shaved scalp, positioned
above the midsagittal suture. After positioning, the metal tip was retracted and
adjusted to a 1-mm depth strike. Scalp of mice were stretched to avoid
delivering a trauma load that was inadequate and at an irregular angle.
Parameters of injury were 5 m/s velocity, depth of 1.0 mm, 200 ms dwell time,
and a projected 72 N strike force. This impact is sublethal; no skull fractures
or subdural hemorrhages have been observed with our injury paradigm. r-mTBI mice
were exposed to 5 hits over 9 days, with a 48-hr interinjury interval. r-sham
mice were exposed to 3 min of anesthesia of the same frequency (×5). After
injury, mice were placed on a 37°C heating pad before return to their normal
cages.
described (
2012
Briefly, we anesthetized sham/injury mice for 3 min with 1.5 L/min of oxygen and
3% isoflurane. We shaved the head of mice and placed them on a stereotaxic frame
(Just For Mice Stereotaxic, Stoelting, Wood Dale, IL) that was mounted with an
electromagnetic controlled impact device (Impact One Stereotaxic Motorized
Impactor, Richmond, IL). Their body temperature was maintained at 37°C on a
heating pad. A flat and blunt 5-mm metal impactor tip mounted onto the
electromagnetic motorized device was zeroed on the shaved scalp, positioned
above the midsagittal suture. After positioning, the metal tip was retracted and
adjusted to a 1-mm depth strike. Scalp of mice were stretched to avoid
delivering a trauma load that was inadequate and at an irregular angle.
Parameters of injury were 5 m/s velocity, depth of 1.0 mm, 200 ms dwell time,
and a projected 72 N strike force. This impact is sublethal; no skull fractures
or subdural hemorrhages have been observed with our injury paradigm. r-mTBI mice
were exposed to 5 hits over 9 days, with a 48-hr interinjury interval. r-sham
mice were exposed to 3 min of anesthesia of the same frequency (×5). After
injury, mice were placed on a 37°C heating pad before return to their normal
cages.