Is inflammatory pulpal pain a risk factor for amnesia

Abstract

The aim of this study was to investigate the effect of inflammatory pulpal pain on spatial learning and memory in male Wistar rats. Fifty-six adult rats were divided into eight groups as follows (n=7 per group): control, sham-operated group that received normal saline, sham vehicle group that received vehicle of capsaicin, three capsaicin treated groups that received intradental injection of 10, 25 and 100 μg capsaicin, respectively, formalin treated group that received 10 μl formalin 2.5% and ibuprofen treated group that received ibuprofen 20 min before capsaicin (100 μg) injection. After preparing cavities via cutting 2 mm of the distal extremities of the mandibular incisors, the polyethylene crowns were placed on the teeth. Based on the study group, different algesics were administrated under the crowns. After recording the pain scores, spatial learning and memory was assessed using Morris water maze test. Capsaicin 25, 100 μg and formalin 2.5% applications induced significantly more painful stimulation compared with control groups (p< 0.001). Capsaicin 25, 100 μg and also formalin-treated groups significantly showed increased escape latency and traveled distance (p<0.05). Oral administration of ibuprofen, 20 min before capsaicin injection, caused significant decrease in pain scores, escape latency and traveled distance. Our data suggest that capsaicin- and formalin-induced pulpal pain can impair spatial learning and memory of male rats in Morris water maze task.