en Clinical Neuroscience Clinical Neuroscience Original Original <p align="left" ><p><b><font color="#221e1f" size="2"><font color="#221e1f" size="2">Introduction:</font></font></b></p><p><b><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2">This study examined the effects of administration of subcutaneous </font></font></font><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2">β-estradiol on PTSD-like symptoms (the enhanced conditioned fear response, CFR) that induced by a single-prolonged stress (SPS) and shock in rats. </font></font></font><b><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"></font></font></font><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2">Adult male Wistar rats were exposed to SPS procedure: restraint for 2 h, forced swim for 20 min, and ether anesthesia. Then the rats were placed in fear </font></font></font><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2">conditioning system and received 1 mA electric foot shock for 4 s. Following, stressed rats injected with β-estradiol (600 μg/kg) or sesame oil. For CFR testing, 24 h later animals were re-exposed to the shock chamber for 3-min without further shock application. Percent of freezing was scored. Following testing, the animals were anesthetized and their brains were removed for histological examination </font></font></font><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2">(cell count) of the hippocampus that stained with cresyl violet. </font></font></font><b><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><p align="justify"><font size="3">Results:</font> </p></font></font></font><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2">Our results indicated that rats who received electric shock after the SPS exhibited the CFR. β-estradiol significantly reduced the CFR in the SPS rats as compared with control rats. No significant differences were found in cell count in </font></font></font><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2">different regions of the hippocampus between experimental groups. </font></font></font><b><font color="#221e1f" size="2"><font color="#221e1f" size="2"><p><font size="3">Discussion:</font> </p></font></font><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2">Our findings indicated that β-estradiol administration after SPS </font></font></font><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2">prevents the enhanced CFR in an animal model of PTSD, suggesting a possible </font></font></font><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2"><font color="#221e1f" face="Times New Roman,Times New Roman" size="2">role for β-estradiol in the prevention of PTSD </font></font></font></b></b></b></b><p></p></p><p align="justify"><font size="3">Methods:</font> </p> Post-Traumatic Stress Disorder,Single-Prolonged Stress,β-Estradiol,Rat. 5 11 http://bcn.iums.ac.ir/browse.php?a_code=A-10-1-93&slc_lang=en&sid=1 Mahdi Mirshekar 1370031947532846001423 1370031947532846001423 Yes Kataneh Abrari 1370031947532846001424 1370031947532846001424 No Iran Goudarzi 1370031947532846001425 1370031947532846001425 No Ali Rashidy-Pour 1370031947532846001426 1370031947532846001426 No