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Authors & Affiliations
Jens Colitti-Klausnitzer, Hardy Hagena, Valentyna Dubovyk, Denise Manahan-Vaughan
Abstract
The medial (MPP) and lateral perforant path (LPP) inputs to the dentate gyrus (DG) comprise a prominent source of information for the hippocampus. Behavioral and anatomical studies have indicated that the MPP provides information about metric space and the LPP provides information about item identity to the hippocampus. This may influence how information is encoded in MPP and LPP inputs to the hippocampus.Here, we examined the frequency-dependency of synaptic plasticity in MPP-DG and LPP-DG synapses of the dorsal hippocampus of freely behaving adult male rats using patterned afferent stimulation at 1, 5, 10, 50, 100, 200Hz during electrophysiological recordings from the dentate gyrus.We observed a bias of MPP-DG synapses towards the expression of synaptic potentiation and a preference of LPP-DG synapses to express synaptic depression. Immunohistochemical analysis revealed no differences in NMDA receptor expression in the target synapses of the MPP and LPP in the DG. Metaplastic priming failed to alter the plasticity preferences of the MPP-DG and LPP- DG in puts indicating that effects are extremely robust and may support a functional differentiation of allocentric and item information processing provided to the DG by the MPP and LPP respectively. Supported by the Deutsche Forschungsgemeinschaft (SFB 1280/A04, project number: 316803389).