Dynamics of Changes in GABA and Catecholamines Contents and MAO-A Activity in Experimental Post-Traumatic Stress Disorder in Rats

Post-traumatic stress disorder (PTSD) develops as a delayed consequence of psychological trauma and is accompanied by characteristic changes in the levels of biogenic amines. The aim of the present work was to carry out a complex study of the dynamics of changes in measures of behavioral activity and noradrenaline and dopamine contents taking cognizance of the activity of the enzyme metabolizing them, i.e., monoamine oxidase A (MAO-A), and the level of the inhibitory transmitter GABA in PTSD. PTSD was modeled in Wistar rats using cat odor. Behavioral changes were studied in the elevated plus maze test. Contents of GABA and catecholamines were determined, along with MAO-A activity levels. The development of poststress anxiety was found to be linked with changes in neurotransmitter levels in the brain. The onset of anxiogenic disorders was preceded by an anxiolytic phase, associated on day 3 with an increase in the GABA level and on day 7 with a decrease in the noradrenaline level in the brain. Only on day 10 was an increase in the noradrenaline content seen, this being synchronized with increases in anxiety. Thus, a significant relationship between the development of behavioral signs of PTSD and an increase in noradrenaline content in the brain was identified.