University of Kentucky
The Whisker Nuisance Task Identifies a Late Onset, Persistent Sensory Sensitivity in Diffuse Brain-Injured Rats
Institution
University of Kentucky
Faculty Advisor/ Mentor
Jonathan Lifshitz
Abstract
ost-traumatic morbidity reduces the quality of life for traumatic brain injury (TBI) survivors by altering neuropsychological function. After midline fluid percussion brain injury (FPI), diffuse pathology in the ventral posterior thalamus suggests that somatosensory whisker function may be impaired post-injury. The goals of the present study were (1) to design and validate a task to detect injury-induced behavioral morbidity and (2) to evaluate preliminary neurorehabilitative interventions to alleviate the morbidity. Male Sprague-Dawley rats were subjected to moderate FPI (~1.9 atm) or sham injury. Post-injury, the whiskers on both mystacial pads were stimulated (15 min) with an applicator stick in an open field. Behavioral responses were recorded using objective criteria (max score = 16). Sham animals were ambivalent or soothed by whisker stimulation (4.0 ±0.8), whereas brain-injured rats showed aggravated responses at 7 days (6.7 ±0.9), which became significant at 28 days (9.5 ±0.5) and 56 days (8.4 ±1.1) compared to sham, indicating chronic injury-induced sensory sensitivity. To implement the Whisker Nuisance Task, additional rats were subjected to mild injury, shaved whiskers, forced whisker stimulation, or tactile exploration of an enriched environment over 28 days post-injury. The Whisker Nuisance Task has the sensitivity to detect mild brain injury, but morbidity is not mitigated by the massed neurorehabilitative interventions. Following diffuse brain injury, the Whisker Nuisance Task is a promising tool to detect post-traumatic morbidity and the efficacy of therapeutic interventions which may translate to restoring discrete circuit function in brain-injured patients.
The Whisker Nuisance Task Identifies a Late Onset, Persistent Sensory Sensitivity in Diffuse Brain-Injured Rats
ost-traumatic morbidity reduces the quality of life for traumatic brain injury (TBI) survivors by altering neuropsychological function. After midline fluid percussion brain injury (FPI), diffuse pathology in the ventral posterior thalamus suggests that somatosensory whisker function may be impaired post-injury. The goals of the present study were (1) to design and validate a task to detect injury-induced behavioral morbidity and (2) to evaluate preliminary neurorehabilitative interventions to alleviate the morbidity. Male Sprague-Dawley rats were subjected to moderate FPI (~1.9 atm) or sham injury. Post-injury, the whiskers on both mystacial pads were stimulated (15 min) with an applicator stick in an open field. Behavioral responses were recorded using objective criteria (max score = 16). Sham animals were ambivalent or soothed by whisker stimulation (4.0 ±0.8), whereas brain-injured rats showed aggravated responses at 7 days (6.7 ±0.9), which became significant at 28 days (9.5 ±0.5) and 56 days (8.4 ±1.1) compared to sham, indicating chronic injury-induced sensory sensitivity. To implement the Whisker Nuisance Task, additional rats were subjected to mild injury, shaved whiskers, forced whisker stimulation, or tactile exploration of an enriched environment over 28 days post-injury. The Whisker Nuisance Task has the sensitivity to detect mild brain injury, but morbidity is not mitigated by the massed neurorehabilitative interventions. Following diffuse brain injury, the Whisker Nuisance Task is a promising tool to detect post-traumatic morbidity and the efficacy of therapeutic interventions which may translate to restoring discrete circuit function in brain-injured patients.