Political Independence and Gifted Students

Detailed projection patterns of septal and diagonal band efferents to the hippocampus in the rat with emphasis on innervation of CA1 and dentate gyrus

“…In agreement with previous observations [18,27], the MS-VDB input pathways follow through the two main timbrial and fomical channels, providing efferents directly to the entire hippocampus or indirectly by traveling over some distance in the alveus. The topographically ordered innervation along the septo-hippocampal axis depends largely if not entirely on the balance between the fornical vs. Iimbrial routes.…”

“…Probably as a result of the lesser sensitivity of these methods though, other fields of hippocampal terminal innervation have either been neglected or have been described as projections of minor importance. This is in particular the case for the middle third Iayer of the stratum moleculare of the dentate gyrus, the stratum moleculare, lacunosum and radiatum of CA1 12 1,271, and the supragranular zone ] 27,29]. It is likely that with the use of degeneration and autoradiographic techniques, only the coarse type I fiber system could be detected more or less successfully, while the type II fibers have remained unobserved.…”

“…There were no significant differences in innervation patterns between the more dorsally (Exps. 29,28,27) or ventrally (Exps. 18,8,26) located injection sites within the medial-lateral group.…”

“…and stratum orient of the CA 1 region 12 I. 25,27,29,36,371. Probably as a result of the lesser sensitivity of these methods though, other fields of hippocampal terminal innervation have either been neglected or have been described as projections of minor importance.…”

“…Recently, with immunocytochemical techniques employing monoclonal antibodies to ChAT, a ChAT-positive lamination became visible in the dentate gyrus and hippocampus proper [ 12,151, which closely corresponds to the previously described distribution of AChE. The link between the origin and terminal arborization of septal afferentation including the cholinergic neurons, however, is still poorly understood despite results obtained with techniques using anterograde degeneration [25,29,361 or anterograde transport of labeled amino acids [21,27,371. This is mainly due to their inherent methodological limitations such as fibers-of-passage problems in degeneration procedures and the lack of distinction between fibers and terminals in 3H-amino acid tracing.…”