Thus, synergistic astrocytic and neuronal GABAergic inhibition could ensure that vasopressin neuron firing is only transiently suppressed under hypoosmotic conditions. “
“Although hippocampal CA1 place cells can be strongly modulated by visual inputs, the effect of visual modulation on place cells in other areas of the hippocampal formation, such as the subiculum, has been less extensively explored. Here, we investigated the role of visual inputs
on CDK and cancer the activity of subicular place cells by manipulating ambient light levels while freely-moving rats foraged for food. Rats were implanted with tetrodes in the dorsal subiculum and units were recorded while the animal performed a pellet-chasing task during multiple light-to-dark and dark-to-light transitions. We found that subicular place fields presented a somewhat heterogeneous response to light–dark transitions, with 45% of pyramidal units showing stable locational firing across multiple light–dark–light transitions. These data suggest that visual inputs may participate in spatial information processing by the subiculum. However, as a plurality of units was stable across light–dark transitions, we suggest that the subiculum supports, probably
in association with the grid cells of the entorhinal cortex, the neurocognitive processing underlying path integration. “
“Temporal lobe epilepsy (TLE) is the most frequent form of epilepsy in adults. In addition to recurrent focal seizures, patients suffer from memory Small molecule library loss and depression. The factors contributing to these symptoms are unknown. In recent years, adult hippocampal neurogenesis has been implicated in certain aspects of learning and memory, as well as in depression and anhedonia. Here we investigated whether the adult hippocampal stem cell niche is affected by status epilepticus in a mouse model of TLE using unilateral intrahippocampal kainic acid injection. Eight days after status epilepticus, we found a strong diminution in Notch signalling, a key pathway involved
in stem cell maintenance, as assayed by hes5 reporter gene activity. In particular, hes5–GFP expression in the subgranular zone of the dentate gyrus was diminished. Furthermore, Sox2-positive cells as well as stem cell proliferation were pheromone reduced, thus pointing to a disruption of the stem cell niche in epilepsy under the present experimental conditions. “
“Following injury to the adult mammalian cochlea, hair cells cannot be spontaneously replaced. Nonetheless, the postnatal cochlea contains progenitor cells, distinguished by the expression of nestin, which are able to proliferate and form neurospheres in vitro. Such resident progenitors might be endowed with reparative potential. However, to date little is known about their behaviour in situ following hair cell injury.