Hippocampal synaptic plasticity in mice devoid of cellular prion protein.
The cellular prion protein plays a role in the etiology of transmissible and inherited spongiform encephalopathies. However, the physiological role of the cellular prion protein is still under debate. Results regarding the synaptic transmission using the same strain of animals where the cellular prion protein gene was ablated are controversial, and need further investigation. In this work, we have studied the hippocampal synaptic transmission in mice devoid of normal cellular prion protein, and have shown that these animals present an increased excitability in this area by the lower threshold (20 Hz) to generate long-term potentiation (LTP) in hippocampal dentate gyrus when compared to wild-type animals. The mice devoid of normal cellular prion protein are also more sensitive to the blocking effects of dizocilpine and 2-amino-5-phosphonopentanoic acid on the hippocampal long-term potentiation generation. In situ hydridization experiments demonstrated overexpression of the mRNAs for the N-methyl-D-aspartate (NMDA) receptor NR2A and NR2B subunits in mice devoid of normal cellular prion protein. Therefore, our results indicate that these animals have an increased hippocampal synaptic plasticity which can be explained by a facilitated glutamatergic transmission. The higher expression of specific N-methyl-d-aspartate receptor subunits may account for these effects.
Maglio
Laura E
LE
Departamento de Farmacología, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, 5000 Córdoba, Argentina.
Perez
Mariela F
MF
Martins
Vilma R
VR
Brentani
Ricardo R
RR
Ramirez
Oscar A
OA
D000818:Animals; D018891:Dentate Gyrus / Q000502:physiology*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D015870:Gene Expression; D017403:In Situ Hybridization; D017774:Long-Term Potentiation / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009473:Neuronal Plasticity / Q000502:physiology*; D018621:PrPC Proteins / Q000235:genetics*; D016194:Receptors, N-Methyl-D-Aspartate / Q000235:genetics
D018691:Excitatory Amino Acid Antagonists; C120997:NR2A NMDA receptor; C121001:NR2B NMDA receptor; D018621:PrPC Proteins; D016194:Receptors, N-Methyl-D-Aspartate; D016291:Dizocilpine Maleate