ABSTRACT
<p><b>OBJECTIVE</b>To observe changes of learning and memory ability (LMA) in burn rats with depression, and study the relationship between LMA and expression of hippocampal NMDA.</p><p><b>METHODS</b>According to simple random method, 46 Wistar rats were divided into burn group (B, with 30% TBSA deep partial-thickness burn, n = 10), depression group (D, with moderate stress stimulation in chronic and unpredictable, n = 12), B + D group (with the same stress stimulation inflicted to B group after burn, n = 12), healthy control group ( HC, without treatment, n = 12). Changes in escape latency was examined in water maze test. Expression of hippocampal NMDA in CA1, CA2 regions and dentate gyrus were observed with immunohistochemistry.</p><p><b>RESULTS</b>Compared with that of HC group (22 +/- 20 s), water maze escape latency in B, D, B + D groups on 2 day after training prolonged (38 +/- 31, 41 +/- 36, 42 +/- 33 s, respectively, P < 0.05 or P < 0.01). Water maze escape latency in B + D group on 4th day after training was longer than that of other groups (P < 0.01). There was no obvious difference in positive expression of NMDA in CA1, CA2 regions among groups (P > 0.05). The positive count of NMDA in dentate gyrus in D group (198 +/- 14) and B + D group (191 +/- 6) were lower than that of HC group (224 +/- 23, P < 0.05 or P < 0.01), but there was no obvious difference between HC group and B group (219 +/- 25, P > 0.05).</p><p><b>CONCLUSIONS</b>Burn complicated with depression can reduce LMA, which may be due to a decrease in NMDA in dentate gyrus.</p>