1. Nitric oxide synthase mediates cerebellar dysfunction in mice exposed to repetitive blast-induced mild traumatic brain injury.
- Author
-
Logsdon AF, Schindler AG, Meabon JS, Yagi M, Herbert MJ, Banks WA, Raskind MA, Marshall DA, Keene CD, Perl DP, Peskind ER, and Cook DG
- Subjects
- Animals, Blast Injuries drug therapy, Blood-Brain Barrier metabolism, Blood-Brain Barrier physiopathology, Brain Concussion drug therapy, Brain Concussion metabolism, Cerebellar Diseases drug therapy, Cerebellum drug effects, Cerebellum metabolism, Disease Models, Animal, Intercellular Adhesion Molecule-1 metabolism, Male, Mice, Mice, Inbred C57BL, NG-Nitroarginine Methyl Ester pharmacology, Purkinje Cells drug effects, Purkinje Cells metabolism, Purkinje Cells pathology, Blast Injuries metabolism, Blast Injuries physiopathology, Brain Concussion physiopathology, Cerebellar Diseases metabolism, Cerebellar Diseases physiopathology, Cerebellum physiopathology, Nitric Oxide Synthase metabolism
- Abstract
We investigated the role of nitric oxide synthase (NOS) in mediating blood-brain barrier (BBB) disruption and peripheral immune cell infiltration in the cerebellum following blast exposure. Repetitive, but not single blast exposure, induced delayed-onset BBB disruption (72 hours post-blast) in cerebellum. The NOS inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) administered after blast blocked BBB disruption and prevented CD4
+ T-cell infiltration into cerebellum. L-NAME also blocked blast-induced increases in intercellular adhesion molecule-1 (ICAM-1), a molecule that plays a critical role in regulating blood-to-brain immune cell trafficking. Blocking NOS-mediated BBB dysfunction during this acute/subacute post-blast interval (24-71 hours after the last blast) also prevented sensorimotor impairment on a rotarod task 30 days later, long after L-NAME cleared the body. In postmortem brains from Veterans/military Servicemembers with blast-related TBI, we found marked Purkinje cell dendritic arbor structural abnormalities, which were comparable to neuropathologic findings in the blast-exposed mice. Taken collectively, these results indicate that blast provokes delayed-onset of NOS-dependent pathogenic cascades that can later emerge as behavioral dysfunction. These results also further implicate the cerebellum as a brain region vulnerable to blast-induced mTBI.- Published
- 2020
- Full Text
- View/download PDF