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BrainSci. 2017,7, 11 respectively [2].Malesaged0–4yearshavethehighest rates forTBI-relatedemergencydepartment visits, hospitalizationsanddeaths combined. Regarding themilitary,DepartmentofDefensedata revealedthat from2000–2011,235,046servicemembers (4.2%of the5,603,720whoserved in theArmy, AirForce,NavyandMarineCorps)werediagnosedwithaTBI [5]. Thus,TBIafflictsmillionsofpeople eachyear, includingcivilianandmilitarypopulations. It ispertinent tonote that thesestatisticsdo notaccount for thosepeoplesufferingfromconcussion/mildTBIwhodidnot receivemedical careor hadoutpatient/office-basedvisits, estimatedbysometobehundredsof thousands, ifnotmillionsof peopleeachyear [3]. 1.2. ClassificationofTBI TheseverityofTBIs is typicallycategorizedusingtheGlasgowComaScaleandcanrangefrom: (a)mild; (b)moderate; to (c) severe [6]. TBIoutcomesareoftendeterminedbyusing theGlasgow OutcomeScale,whichcategorizesgrossneurobehavioral rangesof recovery: (a)dead; (b)vegetative state; (c) severedisability; (d)moderatedisability; (e) goodrecovery [7]. Analternativeprognosis, usingRussell andSmith’s classification, is divided as severe or very severe [8]. Considering that detailedclassificationhelps todetermine theseverityof injury, informstreatmentoptionsandisused toassessprognosisandfunctional recovery, recentsuggestionshave indicatedthatbetterdiagnostic andassessmentcriteriaareneededin theTBIfield[9,10]. 1.3. TBIPrognosis TheeffectsofTBIcanadverselyaffectqualityof life, includingcognitive,behavioral, emotional and physical deficiencies. Any one ormore of these can negatively impact interpersonal, social andoccupational functioning,aswellas families, communitiesandtheeconomyingeneral [11,12]. Impairmentofcognitivefunctioncanleadtodifficultieswithmemory,attention, learning,coordination andsleepdisturbances [12]andcanpersist fordays,monthsorevenyears followingthe initial injury. Other long-termdeficiencies include: languageandcommunicationproblems(19%),dysarthria (30%), dysphagia (17%)[13],mooddisorders [14,15]andcognitive impairment,evensixmonthsaftermild TBI [16].Anotherpost-traumatic syndromethatcanhavearelativelydelayedonset ispost-traumatic epilepsy [14,15,17].Whileall epilepsiesareseizuredisorders,notall seizuresareepilepsy.Assuch, the incidenceofearlypost-traumatic seizures (seizures immediately following,upto thefirst fewdays after theTBI) ishigher than the incidenceofpost-traumatic epilepsy. Notably, about 25%ofbrain contusionpatientsand32%–53%ofpatientswithpenetratingTBIdevelopdifferentdegreesofearly post-traumatic seizures. Post-traumatic seizuresalsoseemtobemoreprevalent followingsevereTBIs, althoughmildandmoderateTBIscanalsoresult inseizures [18]. Considering thenegative impact of thesenumerousdisorders associatedwithpost-traumaticdeficiencies, aswell as the significant numbersofpeople suffering fromthe chronic effects ofTBIs, researchefforts areunderway in the hopesofbetterunderstandingthepathogenicprogression,anddevelopingsuccessful treatmentsof anddiagnosticcriterionforTBI. 2.ABriefReviewofExperimentalTBIAnimalModels InviewoftheheterogeneousclinicalnatureofTBI,numerousanimalmodelshavebeendeveloped forexperimentation.Althoughlargeranimalsarecloser insizeandphysiologytohumans, rodents areavaluableandcommonly-usedmodel inTBIresearch. Theirmodestcost,biological similarities, moremanageablesizeandstandardizedoutcomemeasurementsarealladvantageous. Suchmodels havebeenincorporatedforstudiesaimedat improvingourunderstandingof thedetrimental, complex molecular cascades that are initiated by head trauma, aswell as the long-termneurological and behavioral consequences. Therefore, unlessotherwise indicated, this reviewfocusesondata from animalmodels (primarilyrodents)ofTBI.Amongthem,severalmodelsarewidelyusedinresearch: fluidpercussion injury (FPI) [19–22], cortical impact injury (CCI) [23–25], penetratingballistic-like brain injury[26],weightdrop/impactacceleration injury[27]andblastTBI injury[28,29].Although 131