Showing papers by "Ole Paulsen published in 2003"
TL;DR: It is demonstrated that the postsynaptic requirements for induction of associative long-term potentiation (LTP) shift gradually, explained by a maturational change in GABAergic inhibition, and could have implications for the understanding of the role of inhibition in information processing in the brain.
Abstract: The induction rules of synaptic plasticity are important for the functional operation of a neural network. We asked whether such synaptic plasticity rules change during development from juvenile to adult animals. Using perforated patch and whole-cell recordings from CA1 pyramidal cells in hippocampal slices, we demonstrate here that the postsynaptic requirements for induction of associative long-term potentiation (LTP) shift gradually. Presynaptic stimulation paired with single postsynaptic action potentials became progressively less effective at inducing LTP with advancing developmental age until, in adult hippocampus, postsynaptic bursts of action potentials were necessary to induce synaptic potentiation. This developmental change might be accounted for by changes in GABA A receptor-mediated inhibition known to occur in the hippocampus during this postnatal period, because blocking GABA A receptor-mediated inhibition re-established the effectiveness of single postsynaptic action potentials at inducing LTP in adult hippocampus. These data reveal a gradual shift in the induction rules for LTP, explained by a maturational change in GABAergic inhibition, and could have implications for our understanding of the role of inhibition in information processing in the brain.
170 citations
TL;DR: It is suggested that GABA(B)Rs have an important modulatory role in the migration of cortical interneurons through pre-embedding immunocytochemistry and cell tracking in embryonic brain slice cultures.
Abstract: To better understand the role of neurotransmitter receptors in neuronal differentiation and maturation a detailed knowledge of their identity, location and function in the plasma membrane of specific neuronal populations during development is required. Combining pre-embedding immunocytochemistry with cell tracking in embryonic brain slice cultures we show that virtually all neurons (∼98%) migrating through the lower intermediate zone (LIZ) on their way from the medial ganglionic eminence to the cerebral cortex, express GABABR1. Blockade of GABABRs with a specific antagonist, CGP52432, resulted in a concentration-dependent accumulation of these tangentially migrating neurons in the ventricular/subventricular zones (VZ/SVZ) of the cortex and fewer cells were observed in the cortical plate/marginal zone (CP/MZ) and LIZ. Moreover, they had significantly shorter leading processes compared with similar migrating cells in control slices. Electrophysiological recording in LIZ and CP cells revealed no direct effect of either CGP52432 or the GABABR agonist, baclofen, on resting membrane properties suggesting that the effect of CGP52432 on migration might be mediated through a metabotropic action or the regulation of release of factors controlling migration. These results suggest that GABABRs have an important modulatory role in the migration of cortical interneurons.
139 citations