Effects of Repeated Mild Traumatic Brain Injury and Treatment with a Hepatocyte Growth Factor/MET Activator on Working Memory in Male and Female Long-Evans Rats

STUDY PURPOSE: Investigate the specific role of MET, the tyrosine kinase receptor for hepatocyte growth factor, in modulating working memory function following repeated mild traumatic brain injury (rmTBI). DATA COLLECTED: A total of 52 young adult (8-12 weeks) male (n=33) and female (n=19), Long-Evans rats were randomly assigned to each experimental group in this study. Animals were maintained at 85–100% free-feeding weight through food regulation (5-10% bodyweight of food/day) during training and testing in the T-maze task of working memory. Animals were allowed ad lib access to food during the series of 3 repeated mild closed head injury (CHI) or sham surgeries (every 3 days; e.g. Tues, Fri, Mon). The closed-head injury was conducted using the Custom Design & Fabrication eCCI model 6.3 device. A conical 5 mm diameter metal tip, at an angle perpendicular to the skull surface, was used to impact the skull midline, 2.5 mm caudal to bregma (5.5 m/s, 2.5mm depth, 100ms dwell) of the rat placed on a Marmarou foam block. Cannula was placed in the right lateral ventricle (26 ga.; unilateral right side; -1.0AP, -1.4ML, -1.4DV) during the third CHI surgery. T-maze performance and run time data were acquired manually by the blinded experimenter each day for 5-days after the final injury. Five minutes before behavioral testing, Vehicle (aCSF/Dulbecco's phosphate-buffered saline), Dihexa (1 pmol or 1 nmol in 2 uL vehicle) or Dihexa (1 nmol) + HINGE (KDYIRN, 300pmol / 2?L) was administered ICV. Exclusion criteria included missed placement of the cannula within the lateral ventricle, animals that demonstrated any signs of illness or stress, and/or experimenter error.
Three datasets are provided: the T-Maze behavioral data, the animal weights at the time of each surgery, and the righting reflex times after each CHI or sham injury. DATA USAGE NOTES: