Behavioural and Motor Responses to Induced Fear in Wistar Rats

This study investigated the behavioral and motor responses of induced fear in Wistar rats. Twenty-five wister rats used in this experiment were divided into five groups with each group comprising of five rats. Group I received low dose of glutamate receptor antagonist (GRA), Group II received high dose of GRA, Group III were given low dose of adrenaline, Group IV were given high dose of adrenaline while Group V (control group) were given normal saline. These animals were made to undergo two sets of tests viz; One, Induced Fear and Emotional Reactivity (IFER) Test using light/dark automatic reflex conditioned box to test for their threshold for fear shortly after induction using foot-shock method. The degree of passivity, grooming and escape attempt were noted and recorded and their respective cognitive recovery potentials were measured. Two, the Elevated Plus Maze (EPM) Test was employed to assess their level of fear expression under drug influence. The results and extrapolations suggested that groups administered with glutamate receptor antagonist in both low and high concentrations expressed less enhanced alertness, mental cognition and general awareness in both the light and dark compartments on a short time basis with activities characterized with passivity, grooming and  attempt to escape when compared with those sets of observations in the adrenaline-administered groups both in short and long term durations with much significant influence (p< 0.05). The results of the elevated maze plus (EPM) test followed the same pattern. The present results indicate that induced fear significantly interfered with cognitive activities and normal patterned behaviour in animals and the consequence of this psychic interference played out apparently in after-fear potential (a set of relatively new set of behavioural patterns. The cognitive recovery potential was significantly (p< 0.05) slowest in the glutamate antagonist groups and fastest (p< 0.05) in the adrenaline groups. These observations suggest that excitatory agonists like thiopental (glutamate receptor antagonist) may lack the ability to ameliorate stress-laden influence on brain cognitive circuitry but stress hormones such as adrenaline do in extremely significant fashion.