In vivo blockade of neural activity alters dendritic development of neonatal XXXX pyramidal cells.

@entity1246 @entity11480 @entity1249 @entity1274 @entity35 @entity116
During development, neural activity has been proposed to promote neuronal growth. During the first postnatal week, the hippocampus is characterized by an oscillating @entity1274 and a rapid neuronal growth. In the present study we tested in vivo, by injecting @entity116 toxin into the hippocampus of P1 @entity35 , whether this neural activity indeed promotes growth of pyramidal cells. We have previously shown that @entity116 toxin injection leads to a strong reduction in the frequency of spontaneous @entity1246 and glutamatergic synaptic currents, and to a complete blockade of the early @entity1274 during the first postnatal week. Morphology of @entity11480 -filled @entity1249 pyramidal cells was analyzed at the end of the first postnatal week (P6-10). In activity-reduced neurons, the total length of basal dendritic tree was three times less than control. The number, but not the length, of basal dendritic branches was affected. The growth impairment was restricted to the basal dendrites. The apical dendrite, the axons, or the soma grew normally during activity deprivation. Thus, the in vivo neural activity in the neonate hippocampus seems to promote neuronal growth by initiating novel branches.
