TrkB/BDNF-dependent striatal plasticity and behavior in a genetic model of epilepsy: modulation by valproic acid.
In mice lacking the central domain of the presynaptic scaffold Bassoon the occurrence of repeated cortical seizures induces cell-type-specific plasticity changes resulting in a general enhancement of the feedforward inhibition within the striatal microcircuit. Early antiepileptic treatment with valproic acid (VPA) reduces epileptic attacks, inhibits the emergence of pathological form of plasticity in fast-spiking (FS) interneurons and restores physiological striatal synaptic plasticity in medium spiny (MS) neurons. Brain-derived neurotrophic factor (BDNF) is a key factor for the induction and maintenance of synaptic plasticity and it is also implicated in the mechanisms underlying epilepsy-induced adaptive changes. In this study, we explore the possibility that the TrkB/BDNF system is involved in the striatal modifications associated with the Bassoon gene (Bsn) mutation. In epileptic mice abnormal striatum-dependent learning was paralleled by higher TrkB levels and an altered distribution of BDNF. Accordingly, subchronic intrastriatal administration of k252a, an inhibitor of TrkB receptor tyrosine kinase activity, reversed behavioral alterations in Bsn mutant mice. In addition, in vitro manipulations of the TrkB/BDNF complex by k252a, prevented the emergence of pathological plasticity in FS interneurons. Chronic treatment with VPA, by reducing seizures, was able to rebalance TrkB to control levels favoring a physiological redistribution of BDNF between MS neurons and FS interneurons with a concomitant recovery of striatal plasticity. Our results provide the first indication that BDNF is involved in determining the striatal alterations occurring in the early-onset epileptic syndrome associated with the absence of presynaptic protein Bassoon.
Ghiglieri
Veronica
V
Laboratorio di Neurofisiologia, Fondazione Santa Lucia, IRCCS, Rome, Italy.
Sgobio
Carmelo
C
Patassini
Stefano
S
Bagetta
Vincenza
V
Fejtova
Anna
A
Giampà
Carmela
C
Marinucci
Silvia
S
Heyden
Alexandra
A
Gundelfinger
Eckart D
ED
Fusco
Francesca R
FR
Calabresi
Paolo
P
Picconi
Barbara
B
D000704:Analysis of Variance; D000818:Animals; D000927:Anticonvulsants / Q000627:therapeutic use*; D001362:Avoidance Learning / Q000187:drug effects; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism*; D064026:Calbindins; D002227:Carbazoles / Q000494:pharmacology; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D004558:Electric Stimulation / Q000009:adverse effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004827:Epilepsy / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000235:genetics; D026121:Indole Alkaloids / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009154:Mutation / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000172:deficiency; D009473:Neuronal Plasticity / Q000187:drug effects* / Q000235:genetics; D010320:Parvalbumins / Q000378:metabolism; D018408:Patch-Clamp Techniques; D020813:Receptor, trkB / Q000378:metabolism*; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D014635:Valproic Acid / Q000627:therapeutic use*
D000927:Anticonvulsants; D019208:Brain-Derived Neurotrophic Factor; C498441:Bsn protein, mouse; D064026:Calbindins; D002227:Carbazoles; D004791:Enzyme Inhibitors; D026121:Indole Alkaloids; D009419:Nerve Tissue Proteins; D010320:Parvalbumins; D064030:S100 Calcium Binding Protein G; D014635:Valproic Acid; C049985:staurosporine aglycone; D020813:Receptor, trkB