Date of Graduation


Document Type


Degree Type



Eberly College of Arts and Sciences



Committee Chair

Cole Vonder Haar

Committee Co-Chair

Steven Kinsey

Committee Member

Elizabeth Engler-Chiurazzi


Traumatic brain injury (TBI) impacts millions worldwide and can cause lasting psychiatric symptoms. Chronic neuroinflammation is a characteristic of post-injury pathology and is positively associated with psychiatric conditions such as ADHD and bipolar disorder. Therefore, the current study sought to treat TBI-induced impulsivity and inattention using minocycline, an antibiotic with anti-inflammatory properties. Rats were trained on the five-choice serial reaction time task (5CSRT), a measure of motor impulsivity and attention. After behavior was stable on the 5CSRT, rats received either a bilateral frontal TBI or sham procedure. Minocycline was given at either 1 h post-injury or beginning at 8 weeks after injury. The minocycline treatment consisted of 45mg/kg via intraperitoneal injections given every 12 h for 5 days. Behavioral testing on the 5CSRT began again after one week of recovery and continued for 12 weeks post-injury, then rats were transcardially perfused. Impulsivity and inattention were both substantially increased following TBI. Minocycline at both the early (1 h post-injury) and late (8 weeks post-injury) time points failed to affect TBI-induced impulsivity and inattention. TBI rats had increased lesion volume, but minocycline did not attenuate the lesion size. Additionally, microglia levels measured by IBA-1+ cells did not differ between TBI and sham rats, and minocycline did not differentially change the number of microglia in TBI rats. Based on the results of this study, minocycline does not appear to be an effective treatment for post-injury psychiatric-like symptoms.