In the present study the protective effect of Nigella sativa (N. sativa)on synaptic plasticity impairment induced by lipopolysaccharide (LPS) in rats was investigated. Fifty-eight rats were grouped and treated as follows: 1) control (saline), 2) LPS, 3) LPS-N. sativa,and 4) N. sativa. In a Morris water maze test, the escape latency and traveled path to find t...