Age-dependent long-term potentiation of inhibitory synaptic transmission in rat visual cortex. 1994

Y Komatsu
Department of Physiology, Kyoto Prefectural University of Medicine, Japan.

Long-term potentiation (LTP) of inhibitory synaptic transmission in rat visual cortex was investigated using intracellular recording in slice preparations. The inhibitory postsynaptic potential (IPSP) of layer V cells evoked monosynaptically by layer IV stimulation was recorded while excitatory postsynaptic potentials (EPSPs) were blocked by adding NMDA and non-NMDA receptor antagonists to the perfusate. Separate presynaptic fiber groups were activated by two stimulating electrodes placed in layer IV. One electrode was used to test the effect of conditioning stimulation; the other served as a control. Trains of high-frequency stimulation (50 Hz, 1 sec) were applied at an interval of 10 sec as a conditioning stimulation. The LTP of IPSP induced by the conditioning stimulation had properties similar to those known for LTP of EPSP in hippocampal CA1: (1) it was specific to the conditioned pathway; (2) repetitive application of the conditioning stimulation saturated the LTP; (3) LTP was induced by conditioning stimulation at intensities higher than a threshold; (4) weak conditioning stimulation to one pathway, which alone failed to induce LTP, induced associative LTP when strong conditioning stimulation was simultaneously applied to the other pathway; (5) weak conditioning stimulation sometimes induced short-term potentiation. In contrast to these similarities, LTP of IPSP was induced by a wider range of stimulus frequencies than that capable of generating LTP of EPSPs in CA1. It was induced not only by a brief high-frequency stimulation but also by an intermediate-frequency (2 Hz) stimulation continued for 5 min. In addition, the LTP induction was not dependent on postsynaptic membrane potential. Finally, the LTP of IPSP was more easily induced in developing than in mature rats. This age dependence suggests that LTP of IPSPs may contribute to the improvement of response selectivity of visual cortical cells through visual experience during postnatal development.

UI MeSH Term Description Entries
D009412 Nerve Fibers Slender processes of NEURONS, including the AXONS and their glial envelopes (MYELIN SHEATH). Nerve fibers conduct nerve impulses to and from the CENTRAL NERVOUS SYSTEM. Cerebellar Mossy Fibers,Mossy Fibers, Cerebellar,Cerebellar Mossy Fiber,Mossy Fiber, Cerebellar,Nerve Fiber
D009433 Neural Inhibition The function of opposing or restraining the excitation of neurons or their target excitable cells. Inhibition, Neural
D009435 Synaptic Transmission The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES. Neural Transmission,Neurotransmission,Transmission, Neural,Transmission, Synaptic
D003213 Conditioning, Psychological Simple form of learning involving the formation, strengthening, or weakening of an association between a stimulus and a response. Conditioning, Psychology,Psychological Conditioning,Social Learning Theory,Social Learning Theories,Theory, Social Learning
D004056 Differential Threshold The smallest difference which can be discriminated between two stimuli or one which is barely above the threshold. Difference Limen,Just-Noticeable Difference,Weber-Fechner Law,Difference Limens,Difference, Just-Noticeable,Differences, Just-Noticeable,Differential Thresholds,Just Noticeable Difference,Just-Noticeable Differences,Law, Weber-Fechner,Limen, Difference,Limens, Difference,Threshold, Differential,Thresholds, Differential,Weber Fechner Law
D004558 Electric Stimulation Use of electric potential or currents to elicit biological responses. Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D000375 Aging The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time. Senescence,Aging, Biological,Biological Aging
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D000831 Animals, Newborn Refers to animals in the period of time just after birth. Animals, Neonatal,Animal, Neonatal,Animal, Newborn,Neonatal Animal,Neonatal Animals,Newborn Animal,Newborn Animals
D014793 Visual Cortex Area of the OCCIPITAL LOBE concerned with the processing of visual information relayed via VISUAL PATHWAYS. Area V2,Area V3,Area V4,Area V5,Associative Visual Cortex,Brodmann Area 18,Brodmann Area 19,Brodmann's Area 18,Brodmann's Area 19,Cortical Area V2,Cortical Area V3,Cortical Area V4,Cortical Area V5,Secondary Visual Cortex,Visual Cortex Secondary,Visual Cortex V2,Visual Cortex V3,Visual Cortex V3, V4, V5,Visual Cortex V4,Visual Cortex V5,Visual Cortex, Associative,Visual Motion Area,Extrastriate Cortex,Area 18, Brodmann,Area 18, Brodmann's,Area 19, Brodmann,Area 19, Brodmann's,Area V2, Cortical,Area V3, Cortical,Area V4, Cortical,Area V5, Cortical,Area, Visual Motion,Associative Visual Cortices,Brodmanns Area 18,Brodmanns Area 19,Cortex Secondary, Visual,Cortex V2, Visual,Cortex V3, Visual,Cortex, Associative Visual,Cortex, Extrastriate,Cortex, Secondary Visual,Cortex, Visual,Cortical Area V3s,Extrastriate Cortices,Secondary Visual Cortices,V3, Cortical Area,V3, Visual Cortex,V4, Area,V4, Cortical Area,V5, Area,V5, Cortical Area,V5, Visual Cortex,Visual Cortex Secondaries,Visual Cortex, Secondary,Visual Motion Areas
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