Calbindin D28K expression in relation to granule cell dispersion, mossy fibre sprouting and memory impairment in hippocampal sclerosis: A surgical and post mortem series

Correlation between calbindin expression in granule cells of the resected hippocampal dentate gyrus and verbal memory in temporal lobe epilepsy

“…Our results seem to contradict recent results of Martinian et al [68] who could not detect a significant correlation between CB expression and memory function of patients with HS [68]. In HS, however, memory impairment is also influenced by neuronal loss, not only by the decreased CB expression of the granule cells.…”

“…In fact, in animal models of TLE, the decreased CB expression can be detected only ipsilaterally but not contralaterally [67]. Autopsy following TLE revealed that loss of CB in the granule cells was evident in the dentate gyrus only on the side of the focus [68].…”

Variability of sclerosis along the longitudinal hippocampal axis in epilepsy: A post mortem study

“…However, pathological alterations were observed along the hippocampal length extending into the hippocampal tail in some cases. We have also recently reported on distinct patterns of restricted absence of CB expression from basal granule cells in HS (Martinian et al, 2012) and that this may relate to early onset of seizures and impaired normal maturation (Abraham et al, 2009). In the present series, we showed similar alteration in CB expression in granule cells, even involving sections from the hippocampal tail.…”

“…(l–n) Calbindin in the dentate gyrus. The patterns of labelling in the granule cells was graded as recently described (Martinian et al, 2012): (l) normal pattern with labelling of majority of granule cell neurones and apical dendrites (Grade 0), (m) loss of CB expression (Grade 1), (n) basal granule cells negative and dispersed granule cells positive (Grade 2). Bar = 45 μm.…”

Revisiting hippocampal sclerosis in mesial temporal lobe epilepsy according to the “two-hit” hypothesis

“…In epileptic tissue, mossy fiber sprouting is thought to be triggered early by both hippocampal seizures and neuronal loss and confers to sprouting an important role in epileptogenesis [2,4,6,86]. Some recent data suggested that newly generated cells form a significant contribution to mossy fiber sprouting [82,87] and that hilar ectopic granule cells receive more excitatory inputs from other granule cells and generate spontaneous epileptiform bursts [83,88]. These ''hub cells'' may be able to synchronize network activity by receiving inputs from unusually large population of neurons and then excitating an aberrantly large target network [83,84,89].…”