TLRs expression is determined by brain maturity. (a) Brain sections from P3 (first column), P5 (second column), and P7 (third column) old rat pups were processed for TLR-2 (top panel), -3 (middle panel), and -4 (bottom panel) immuno-staining as described in Methods. There was a higher cortical expression of TLR-3 in P5 rat brain compared to P3 and P7 whereas TLR-4 was highly expressed in P7 rat brain. Brown color (arrow) denotes positive cell. (b) Number of TLRs positive cortical cells was counted by blinded investigator in at least four high power microscopic fields (40×) in each specimen and compared between age groups. *
P <0.05 when compared to P7. ξ
P <0.05 when compared to the other two age groups. There was no significant difference in TLR-9 expression among the three age groups (n = 15-30 pups/age group).