en Behavioral Neuroscience Behavioral Neuroscience Original Original <p dir="ltr" style="text-align: justify;"><strong>Introduction:</strong> Several studies have reported the involvement of age-related changes in the&nbsp;development of neuropathic pain behaviors. However, limited data are available on the role of age in&nbsp;establishing and maintaining chronic neuropathic pain after peripheral nerve injury.<br> <strong>Methods:</strong> In the present study, we examined age-related neuropathic behavior among rats in 4 age&nbsp;groups: pups (4 weeks old; weight, 60&ndash;80 g), juvenile rats (6 weeks old; weight, 120&ndash;140 g), and&nbsp;mature rats (10&ndash;12 weeks old; weight, 200&ndash;250 g). Because the exact contribution of spinal microglia&nbsp;and its association with the development of neuropathic pain remains unknown, we also evaluated the&nbsp;expression of spinal Iba1, a microglial marker, by using western blotting before and 5 days after spinal&nbsp;nerve ligation (SNL) as well as after the daily IP administration of minocycline (30 mg/kg).<br> <strong>Results:</strong> Our results showed that SNL-induced mechanical allodynia but not thermal hyperalgesia&nbsp;in mature rats but not in pups (P<0.05 and P<0.01, respectively). The expression of spinal Iba1&nbsp;in the juvenile rats was significantly lower than that in pups and mature rats (P<0.01). Moreover,&nbsp;administration of minocycline decreased the expression of spinal Iba1 in the pup rats more than in&nbsp;juvenile rats (P<0.001) and in the juvenile rats more than in the mature rats (P<0.05).<br> <strong>Conclusion: </strong>These data suggest that the development of neuropathic behaviors and microglial&nbsp;activation after SNL could be age dependent.</p> Age- related, Hyperalgesia, Allodynia, Iba1 203 212 http://bcn.iums.ac.ir/browse.php?a_code=A-10-710-1&slc_lang=en&sid=1 Hossien Zeinali hzeinali53@gmail.com 1370031947532846007947 1370031947532846007947 No Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Homa Manaheji manahejih@sbmu.ac.ir 1370031947532846007948 1370031947532846007948 Yes Neurophysiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Jalal Zaringhalam Jzaringhalam@yahoo.com 1370031947532846007949 1370031947532846007949 No Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Zahra Bahari bahari_441@yahoo.com 1370031947532846007950 1370031947532846007950 No Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Samad Nazemi samadnazami@gmail.com 1370031947532846007951 1370031947532846007951 No Department of Physiology, School of Medicine, Sabzevar University of Medical Sciences, Sabzevar, Iran. Mehdi Sadeghi sadeghi_mehdi@yahoo.com 1370031947532846007952 1370031947532846007952 No Department of Physiology, Faculty of Medicine, Boushehr University of Medical Sciences, Boushehr, Iran.