This study examined the effects of blast injury on parvalbumin expression in the visual cortex and retrosplenial cortex of mice. Mice received a nonlethal blast with or without the analgesic Buprenex. Immunocytochemistry showed levels of parvalbumin were statistically changed after blast. Buprenex decreased parvalbumin in sham mice but increased it in blasted mice. This suggests Buprenex confounds interpretation of traumatic brain injury studies.