Citation

Heim LR, Badar M, Edut S, Rachmany L, Baratz R, Lin R, Elpaz A, Qubty D, Bikovski L, Rubovitch V, Schreiber S, Pick CG. J. Neurotrauma 2017; 34(17): 2518-2528.

Affiliation

The Dr. Miriam and Sheldon G. Adelson Chair and Center for the Biology of Addictive Diseases, Tel-Aviv, Israel ; pickc@post.tau.ac.il.

Copyright

(Copyright © 2017, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2016.4909

PMID

28514188

Abstract

The present study was designed to tackle two notorious features of mild Traumatic Brain Injury (mTBI) - heterogeneity and invisibility - by characterizing the full scope of mTBI symptoms. Mice were exposed to brain injuries of different intensities utilizing a weight-drop model (10, 30, 50, and 70g), and subsequently subjected to a comprehensive battery of behavioral tests at different time points, and immunohistochemical examination of cortical slices. While the physiological, neurological, emotional, and motor function of mTBI mice, i.e. their well-being, remained largely intact, cognitive deficits were identified by the y-maze and novel object recognition.

RESULTS from these two cognitive tests were combined and a dose-response relationship was established between injury intensity and cognitive impairment, ranging from an 85% decline following a 70g impact (p<0.001) to a 20% decline following a 10g impact (essentially no effect). In addition, higher intensities of injury were accompanied by decreased expression of axonal and synaptic markers. Thus, our mTBI mice showed a clear discrepancy between performance (poor cognitive function) and appearance (healthy demeanor). This is of major concern given that diagnosis of mTBI is established on the presence of clinical symptoms, and emphasizes the need for an alternative diagnostic modality.

Language: en

Keywords

ANIMAL STUDIES; BEHAVIORAL ASSESSMENTS; COGNITIVE FUNCTION; HEAD TRAUMA; TRAUMATIC BRAIN INJURY