TY - JOUR
T1 - Seizures accelerate functional integration of adult-generated granule cells
AU - Overstreet-Wadiche, Linda S.
AU - Bromberg, Daniel A.
AU - Bensen, Ae Soon L.
AU - Westbrook, Gary L.
PY - 2006
Y1 - 2006
N2 - In humans and experimental animals, structural and functional changes in neural circuits can accompany the development of epilepsy. In the dentate gyrus, seizures enhance adult neurogenesis, but it is unclear to what extent newborn granule cells participate in seizure-induced synaptic reorganization. During the first weeks of their existence, mouse newborn granule cells labeled with enhanced green fluorescent protein have only short dendrites that lack excitatory input. We report that pilocarpine-induced seizures accelerated the morphological development of labeled granule cells, causing their dendrites to extend through the molecular layer. In whole-cell recordings 5-16 d after seizure induction, perforant-path stimulation now evoked glutamatergic input to newborn granule cells. These synaptic responses were mediated by monosynaptic as well as recurrent polysynaptic input. Thus, seizures facilitated functional integration of adult-generated granule cells.Onemonthlater, subsequent generations of newborn cells also showed alterations in dendrite morphology, suggesting persistent effects of seizures on granule cell maturation. The sensitivity of newborn granule cells to seizures could contribute to hyperexcitability during the latent period.
AB - In humans and experimental animals, structural and functional changes in neural circuits can accompany the development of epilepsy. In the dentate gyrus, seizures enhance adult neurogenesis, but it is unclear to what extent newborn granule cells participate in seizure-induced synaptic reorganization. During the first weeks of their existence, mouse newborn granule cells labeled with enhanced green fluorescent protein have only short dendrites that lack excitatory input. We report that pilocarpine-induced seizures accelerated the morphological development of labeled granule cells, causing their dendrites to extend through the molecular layer. In whole-cell recordings 5-16 d after seizure induction, perforant-path stimulation now evoked glutamatergic input to newborn granule cells. These synaptic responses were mediated by monosynaptic as well as recurrent polysynaptic input. Thus, seizures facilitated functional integration of adult-generated granule cells.Onemonthlater, subsequent generations of newborn cells also showed alterations in dendrite morphology, suggesting persistent effects of seizures on granule cell maturation. The sensitivity of newborn granule cells to seizures could contribute to hyperexcitability during the latent period.
KW - Adult neurogenesis
KW - Dentate gyrus
KW - Epilepsy
KW - Mossy fiber sprouting
KW - Recurrent EPSCs
KW - Synaptic transmission
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UR - http://www.scopus.com/inward/citedby.url?scp=33646102681&partnerID=8YFLogxK
U2 - 10.1523/JNEUROSCI.5508-05.2006
DO - 10.1523/JNEUROSCI.5508-05.2006
M3 - Article
C2 - 16611826
AN - SCOPUS:33646102681
SN - 0270-6474
VL - 26
SP - 4095
EP - 4103
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 15
ER -