Effects of Metals Exposure after Traumatic Brain Injury on Learning and Memory

Abstract

Traumatic brain injury (TBI) is a major reason of mortality around the world. TBI is linked with severe deficits in sensorimotor function, memory personality and cognitive behaviour. Heavy metals are known neurotoxicant, their chronic exposure cause cognitive and memory deficits. Aluminium, arsenic and lead are considered to be the most significant causes of neurological impairment. However, their combined effect is yet to be known. This study aims to evaluate the effects caused by the exposure of these metals on cognition, learning and memory. The design of the experiment included six groups of Balb/c mice. Except the control group the five group were induced with the focal head injury using the weight-drop technique. Control and Trauma were given normal saline water while PoTAl (aluminium 20 mg/kg),PoTPb (lead 20 mg/kg), PoTAs (arsenic 20 mg/kg) and PoTM (aluminium, lead and arsenic 20mg/kg each) were given metal doses in water. Neurological severity score (NSS) was measured at different time intervals to check severity of trauma. Effects of these metals exposure after trauma was assessed by behavioral tests like Morris water maze (MWM) , Novel object recognition (NOR), Elevated plus maze (EPM), Fear conditioning and contextual fear and open field test were conducted. The result of each test was presented by a graph. The graph of Morris water maze test, Fear conditioning and contextual fear and novel object recognition test revealed an aggravated level of learning and memory in metals treated mice. Elevated plus maze test and the open field test showed high level of anxiety and depression in metals treated mice. Further studies for in-vitro verification of these results and evaluation of neuronal effects of metals in combination after trauma is required to develop better regime of drug.