Neuronal NT-3 is not required for synaptic transmission or long-term potentiation in area CA1 of the adult rat hippocampus.
Neurotrophic factors, including BDNF and NT-3, have been implicated in the regulation of synaptic transmission and plasticity. Previous attempts to analyze synaptic transmission and plasticity in mice lacking the NT-3 gene have been hampered by the early death of the NT-3 homozygous knockout animals. We have bypassed this problem by examining synaptic transmission in mice in which the NT-3 gene is deleted in neurons later in development, by crossing animals expressing the CRE recombinase driven by the synapsin I promoter to animals in which the NT-3 gene is floxed. We conducted blind field potential recordings at the Schaffer collateral-CA1 synapse in hippocampal slices from homozygous knockout and wild-type mice. We examined the following indices of synaptic transmission: (1) input-output relationship; (2) paired-pulse facilitation; (3) post-tetanic potentiation; and (4) long-term potentiation: induced by two different protocols: (a) two trains of 100-Hz stimulation and (b) theta burst stimulation. We found no difference between the knockout and wild-type mice in any of the above measurements. These results suggest that neuronal NT-3 does not play an essential role in normal synaptic transmission and some forms of plasticity in the mouse hippocampus.
Ma
L
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University of Texas, Southwestern Medical Center, Center for Developmental Biology, Dallas 75235-9133, USA.
Reis
G
G
Parada
L F
LF
Schuman
E M
EM
D000818:Animals; D015152:Blotting, Northern; D015139:Blotting, Southern; D004594:Electrophysiology; D017353:Gene Deletion; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D007091:Image Processing, Computer-Assisted; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D009414:Nerve Growth Factors / Q000235:genetics* / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D020933:Neurotrophin 3; D051381:Rats; D009435:Synaptic Transmission / Q000502:physiology*
D009414:Nerve Growth Factors; D020933:Neurotrophin 3