Regional cerebral blood volume (rCBV) and trasversal relaxationtime (T2) mapping of the rat limbic system duringpre-puberal and adult age

We analyzed modifications in transversal relaxation time (T2) and regional cerebral blood volume (rCBV) in two areas of the limbic system, i.e., olfactory bulb (OB) and amygdala (AMY), in pre-puberty and post-puberty female rats. The aim of this work was to extend the knowledge about physiological modifications of these MRI parameters at different developmental phases. No significant difference was observed in T2 values of the OB between the two groups (pre-puberty: T2 = 86.92 ± 8.57 ms, post-puberty: T2 = 88.11 ± 13.06 ms; mean ± S.D.). On the contrary T2 values of the AMY were significantly different (P = 0.0001) between the two groups (pre-puberty 76.08 ± 3.2, post-puberty 81.77 ± 11.77 ms). rCBV values of OB were significantly different (P = 0.0025) between pre-puberty (0.38 ± 0.12 a.u.) and post-puberty female rats (0.15±0.09 a.u.). A significant decrease in rCBV (P = 5.1×10−13) between pre-puberty and post-puberty females (pre-puberty: 0.36 ± 0.12, post-puberty: 0.07 ± 0.05 a.u.) was also observed in the AMY. These findings suggest that in the limbic system, microvascular plasticity parallels neuronal maturation and indicate the importance of an appropriate baseline study in experiments dealing with the limbic system performed at different time-points.