TY - JOUR
T1 - Dynamic changes in the recovery after traumatic brain injury in mice
T2 - Effect of injury severity on T2-weighted MRI abnormalities, and motor and cognitive functions
AU - Tsenter, Jeanna
AU - Beni-Adani, Liana
AU - Assaf, Yaniv
AU - Alexandrovich, Alexander G.
AU - Trembovler, Victoria
AU - Shohami, Esther
PY - 2008/4/1
Y1 - 2008/4/1
N2 - Memory and neurobehavioral dysfunctions are among the sequelae of traumatic brain injury (TBI). The Neurological Severity Score (NSS) includes 10 tasks and was previously designed to assess the functional status of mice after TBI. The object recognition task (ORT) measures specific episodic memory and is expressed by the percent time spent by an animal at a novel, unfamiliar object (Discrimination Index [DI]). It is an ideal tool for evaluating cognitive function after TBI. The present study sought to validate the use of the NSS and ORT in severe and mild focal TBI in mice, and to confirm that the spontaneous recovery and the radiological abnormalities, shown by T2-weighted magnetic resonance imaging (MRI), are dependent upon injury severity. Mice were subjected to severe and mild closed head injury (NSS at 1 h 7.52 ± 0.34 and 4.62 ± 0.14, respectively). NSS was evaluated for 25 days and showed a decrease by 3.86 ± 0.26 and 2.54 ± 0.35 units in the severely and mildly injured mice, respectively. ORT revealed DI in severely injured group of 51.7 ± 6.15%, (vs ∼75-80% in uninjured animal) on day 3 and 66.2 ± 6.81% on day 21. In contrast, the mildly injured mice did not show cognitive impairment throughout the same period. The damage seen by MRI at 24 h after injury, strongly correlated with NSS(1h) (R = 0.87, p < 0.001). We conclude that NSS is a reliable tool for evaluation of neurological damage in head-injured mice, NSS(1h) predicts the motor dysfunction, cognitive damage, and brain-damage characteristics as depicted by T2-weighted MRI. The combined assessment of neurobehavioral and cognitive function along with MRI is most useful in evaluating recovery from injury, especially when testing effectiveness of novel treatments or genetic manipulations.
AB - Memory and neurobehavioral dysfunctions are among the sequelae of traumatic brain injury (TBI). The Neurological Severity Score (NSS) includes 10 tasks and was previously designed to assess the functional status of mice after TBI. The object recognition task (ORT) measures specific episodic memory and is expressed by the percent time spent by an animal at a novel, unfamiliar object (Discrimination Index [DI]). It is an ideal tool for evaluating cognitive function after TBI. The present study sought to validate the use of the NSS and ORT in severe and mild focal TBI in mice, and to confirm that the spontaneous recovery and the radiological abnormalities, shown by T2-weighted magnetic resonance imaging (MRI), are dependent upon injury severity. Mice were subjected to severe and mild closed head injury (NSS at 1 h 7.52 ± 0.34 and 4.62 ± 0.14, respectively). NSS was evaluated for 25 days and showed a decrease by 3.86 ± 0.26 and 2.54 ± 0.35 units in the severely and mildly injured mice, respectively. ORT revealed DI in severely injured group of 51.7 ± 6.15%, (vs ∼75-80% in uninjured animal) on day 3 and 66.2 ± 6.81% on day 21. In contrast, the mildly injured mice did not show cognitive impairment throughout the same period. The damage seen by MRI at 24 h after injury, strongly correlated with NSS(1h) (R = 0.87, p < 0.001). We conclude that NSS is a reliable tool for evaluation of neurological damage in head-injured mice, NSS(1h) predicts the motor dysfunction, cognitive damage, and brain-damage characteristics as depicted by T2-weighted MRI. The combined assessment of neurobehavioral and cognitive function along with MRI is most useful in evaluating recovery from injury, especially when testing effectiveness of novel treatments or genetic manipulations.
KW - Closed head injury
KW - Memory
KW - Object recognition
KW - Outcome measures
UR - http://www.scopus.com/inward/record.url?scp=41449108080&partnerID=8YFLogxK
U2 - 10.1089/neu.2007.0452
DO - 10.1089/neu.2007.0452
M3 - Article
C2 - 18373482
AN - SCOPUS:41449108080
SN - 0897-7151
VL - 25
SP - 324
EP - 333
JO - Journal of Neurotrauma
JF - Journal of Neurotrauma
IS - 4
ER -