Granule cell (GC) neurogenesis in the dentate gyrus (DG) does not always proceed normally. After severe @entity410 (e.g., @entity159 [ @entity159 ]) and some other conditions, newborn GCs appear in the hilus. Hilar ectopic GCs (EGCs) can potentially provide insight into the effects of abnormal location and @entity410 on GC development. Additionally, hilar EGCs that develop after @entity159 may contribute to epileptogenesis and @entity73 that follow @entity159 . Thus, it is critical to understand how EGCs differ from normal GCs. Relatively little morphometric information is available on EGCs, especially those restricted to the hilus. This study quantitatively analyzed the structural morphology of hilar EGCs from adult male @entity35 several months after @entity2134 -induced @entity159 , when they are considered to have chronic @entity302 . Hilar EGCs were physiologically identified in slices, intracellularly labeled, processed for light microscopic reconstruction, and compared to GC layer GCs, from both the same post- @entity159 tissue and the NeuroMorpho database (normal GCs). Consistently, hilar EGC and GC layer GCs had similar dendritic lengths and field sizes, and identifiable apical dendrites. However, hilar EGC dendrites were topologically more complex, with more branch points and tortuous dendritic paths. Three-dimensional analysis revealed that, remarkably, hilar EGC dendrites often extended along the longitudinal DG axis, suggesting increased capacity for septotemporal integration. Axonal reconstruction demonstrated that hilar EGCs contributed to mossy fiber sprouting. This combination of preserved and aberrant morphological features, potentially supporting convergent afferent input to EGCs and broad, divergent efferent output, could help explain why the hilar EGC population could impair DG function.

Morphometry of hilar ectopic granule cells in the XXXX .

@entity410 :: ('MESH:D012640', 'Disease') :: ['seizures'] @entity73 :: ('MESH:D003072', 'Disease') :: ['cognitive impairments'] @entity2134 :: ('MESH:D010862', 'Chemical') :: ['pilocarpine'] @entity302 :: ('MESH:D004827', 'Disease') :: ['epilepsy'] @entity35 :: ('10116', 'Species') :: ['rats'] @entity159 :: ('MESH:D013226', 'Disease') :: ['status epilepticus', 'SE']
@entity35 :: (10116,Species) :: ['rat']
