title: Motor Training Promotes Both Synaptic and Intrinsic Plasticity of Layer II/III Pyramidal Neurons in the Primary Motor Cortex.
abstract: Motor skill training induces structural plasticity at dendritic spines in the primary motor cortex (M1). To further analyze both synaptic and intrinsic plasticity in the layer II/III area of M1, we subjected rats to a rotor rod test and then prepared acute brain slices. Motor skill consistently improved within 2 days of training. Voltage clamp analysis showed significantly higher α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid/N-methyl-d-aspartate (AMPA/NMDA) ratios and miniature EPSC amplitudes in 1-day trained rats compared with untrained rats, suggesting increased postsynaptic AMPA receptors in the early phase of motor learning. Compared with untrained controls, 2-days trained rats showed significantly higher miniature EPSC amplitude and frequency. Paired-pulse analysis further demonstrated lower rates in 2-days trained rats, suggesting increased presynaptic glutamate release during the late phase of learning. One-day trained rats showed decreased miniature IPSC frequency and increased paired-pulse analysis of evoked IPSC, suggesting a transient decrease in presynaptic γ-aminobutyric acid (GABA) release. Moreover, current clamp analysis revealed lower resting membrane potential, higher spike threshold, and deeper afterhyperpolarization in 1-day trained rats-while 2-days trained rats showed higher membrane potential, suggesting dynamic changes in intrinsic properties. Our present results indicate dynamic changes in glutamatergic, GABAergic, and intrinsic plasticity in M1 layer II/III neurons after the motor training.
authors.affiliation: Department of Physiology.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kida
authors.affiliation: Department of Physiology.
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Tsuda
authors.affiliation: Department of Physiology.
authors.forename: Nana
authors.initials: N
authors.lastname: Ito
authors.affiliation: Department of Organ Anatomy, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Yui
authors.initials: Y
authors.lastname: Yamamoto
authors.affiliation: Department of Organ Anatomy, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Owada
authors.affiliation: Uonuma Institute of Community Medicine, Niigata University Medical and Dental Hospital, 4132 Urasa, Minami-uonuma, Niigata 949-7302, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Kamiya
authors.affiliation: Department of Physiology.
authors.forename: Dai
authors.initials: D
authors.lastname: Mitsushima
mesh_terms: D000818:Animals; D018698:Glutamic Acid / Q000378:metabolism; D007858:Learning / Q000502:physiology*; D008297:Male; D008564:Membrane Potentials; D009044:Motor Cortex / Q000187:drug effects / Q000502:physiology*; D009048:Motor Skills / Q000502:physiology*; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D017966:Pyramidal Cells / Q000187:drug effects / Q000502:physiology*; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D045442:Rotarod Performance Test; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D046509:Tissue Culture Techniques; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
chemical_list: D018377:Neurotransmitter Agents; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid
keywords: AMPA receptor; GABA; glutamic acid; motor learning