title: Postnatal development and sensory experience synergistically underlie the excitatory/inhibitory features of hippocampal neural circuits: Glutamatergic and GABAergic neurotransmission.
abstract: During a postnatal critical period balance of excitation/inhibition in the developing brain is highly regulated by environmental signals. Compared to the visual cortex, rare document includes effects of sensory experience on the hippocampus, which is also bombarded by sensory signals. In this study, basic and tetanized field excitatory postsynaptic potentials (fEPSPs) were recorded in CA1 area of hippocampus of light-(LR) and dark-reared (DR) rats (at 2, 4 and 6weeks of age). Also, we assessed age- and activity-dependent changes in the N-Methyl-d-aspartic acid (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors subunit compositions and, GABA producing enzymes. While the sensory deprivation increased amplitude of baseline fEPSPs, it decreased degree of potentiation of post-tetanus responses. Expression of GluA1 and GluA2 subunits of AMPA receptors was increased across age in DR rats. In contrast to LR rats, mRNA and protein expression of GluN1, GluN2A and GluN2B subunits of NMDA receptors was decreased in DR ones. Also, dark rearing diminished expression of GABA synthesis enzymes GAD65 and GAD67. These results indicate that, sensory experience adjusts synaptic plasticity and might also affect the balance of excitation/inhibition in the hippocampus.
authors.affiliation: Physiology Research Center, Kashan University of Medical Sciences, Kashan, Islamic Republic of Iran.
authors.forename: S A
authors.initials: SA
authors.lastname: Talaei
authors.affiliation: Anatomical Sciences Research Center, Kashan University of Medical Sciences, Kashan, Islamic Republic of Iran.
authors.forename: A
authors.initials: A
authors.lastname: Azami
authors.affiliation: Physiology Research Center, Kashan University of Medical Sciences, Kashan, Islamic Republic of Iran. Electronic address: salami-m@kaums.ac.ir.
authors.forename: M
authors.initials: M
authors.lastname: Salami
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects; D059330:GABAergic Neurons / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects*; D008297:Male; D009473:Neuronal Plasticity / Q000187:drug effects* / Q000502:physiology; D017966:Pyramidal Cells / Q000187:drug effects / Q000502:physiology; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000378:metabolism; D009435:Synaptic Transmission / Q000187:drug effects* / Q000502:physiology; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid / Q000494:pharmacology
chemical_list: D018091:Receptors, AMPA; D018350:alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid
keywords: excitatory/inhibitory neurotransmission; hippocampus; postnatal development; rat; synaptic plasticity; visual experience