Abstract
The molecular and cellular mechanisms underlying experience-dependent plasticity of brain function are poorly understood. Recent in vitro studies have identified the regulated trafficking of AMPA receptors (-Rs) into synapses as a major molecular component of neural plasticity. Here we ask if experience-driven plasticity in the developing rat barrel cortex is accompanied by and/or requires AMPA-R delivery to synapses. By combining in vivo gene delivery with in vitro recordings, we show that experience drives recombinant GluR1, an AMPA-R subunit, into synapses formed between layer 4 and layer 2/3 neurons. Furthermore, expression of the GluR1 cytoplasmic tail in layer 2/3 neurons, a construct that inhibits synaptic delivery of endogenous AMPA receptors during long-term potentiation, blocks experience-driven synaptic potentiation. These studies show that synaptic delivery of AMPA-Rs contributes to plasticity driven by natural stimuli in the mammalian brain.Although social isolation early in life has been shown to alter behaviors including learning and emotion, how neonatal isolation affects synaptic connection is poorly understood. Since whisker-barrel system is involved in social interaction, we examined if social isolation changes experience-dependent synaptic delivery of AMPA receptors in the developing rat barrel cortex. We found that neonatal social isolation disrupted in vivo trafficking of GluR1 and GluR4 into synapses formed from layer 4 to layer 2/3 of developing rat barrel cortex. These data suggested that neonatal social isolation alters neuronal reorganization by disruption of experience-driven synaptic delivery of AMPA receptors. [J Physiol Sci. 2008;58 Suppl:S34]
