Journal:

Article Title: Dynamic modulation of short term synaptic plasticity in the auditory cortex: the role of norepinephrine

doi: 10.1016/j.heares.2010.08.014

Figure Lengend Snippet: Short-term plasticity of GABAergic synaptic transmission in responses to electrical stimulation at different frequencies. A, B, and C: representative traces of synaptic responses evoked by electrical stimulation of layer I with a 1s-long pulse trains at 5, 10 Hz, and 20 Hz, respectively (n = 15). D, E, and F: representative traces of synaptic responses evoked by pulse trains at 5, 10 and 20 Hz in layer II/III (n = 15). Short term synaptic depression was observed in both LI-eIPSCs and LII/III eIPSCs. G–I, eIPSCs amplitude vs. pulse number at at 5, 10, and 20 Hz for LI and LII/III eIPSCs. J–L: normalized synaptic depression vs. pulse number at 5, 10, and 20 Hz, same sample as above.

Article Snippet: Electrically evoked IPSCs (eIPSCs) were measured by delivering trains of monophasic electric stimuli (ranges 90–180 μs, 10–50 μA) at 5, 10 or 20 Hz every 20 sec, with an isolation unit, through a glass stimulation monopolar electrode filled with ACSF, or with a concentric bipolar electrode (FHC Inc, ME), placed at about 100–200 μm lateral from the axis between the recorded neuron and the cortical neuropil, perpendicular to the latter, in either layer I (LI-eIPSCs), or layer II/III (LII/III-eIPSCs).

Techniques: Transmission Assay

Journal:

Article Title: Dynamic modulation of short term synaptic plasticity in the auditory cortex: the role of norepinephrine

doi: 10.1016/j.heares.2010.08.014

Figure Lengend Snippet: IPSC amplitude dependence on the extracellular concentration of Ca2+([Ca2+]o) A: representative traces of synaptic responses evoked in LI by 20 Hz stimulation in control (black) and low Ca2+ (red). B: decreasing [Ca2+]o from 1.5 mM to 0.5 mM (low Ca2+) reduced the eIPSCs amplitude during the initial part of the response, while recovering it at the end of the train. C: low Ca2+ converted synaptic depression into facilitation on LI-eIPSCs (n = 6). D–F: increasing [Ca2+]o from 1.5 mM to 2.5 mM (high Ca2+) increased eIPSCs amplitude during the initial part of the response. F: The high Ca2+ condition further accelerated the depression of LI-eIPSCs (n = 6). G–I: representative traces, eIPSCs amplitudes and ratios (IPSCn/IPSC1) as in A, B, and C, but for LII/III-eIPSCs in control and low Ca2+. Note that low Ca2+ converts synaptic depression into facilitation at the end of the train (fig. 2I, n = 6). J–L: As in D, E, and F, but for LII/III-eIPSCs. High Ca2+ accelerated the depression of LII/III-eIPSCs.

Article Snippet: Electrically evoked IPSCs (eIPSCs) were measured by delivering trains of monophasic electric stimuli (ranges 90–180 μs, 10–50 μA) at 5, 10 or 20 Hz every 20 sec, with an isolation unit, through a glass stimulation monopolar electrode filled with ACSF, or with a concentric bipolar electrode (FHC Inc, ME), placed at about 100–200 μm lateral from the axis between the recorded neuron and the cortical neuropil, perpendicular to the latter, in either layer I (LI-eIPSCs), or layer II/III (LII/III-eIPSCs).

Techniques: Concentration Assay, Control

Journal:

Article Title: Dynamic modulation of short term synaptic plasticity in the auditory cortex: the role of norepinephrine

doi: 10.1016/j.heares.2010.08.014

Figure Lengend Snippet: NE modulation of the absolute peak amplitudes of LI-eIPSCs and LII/III-eIPSCs. A: NE reduced homogeneously LI-eIPSCs amplitude during 5 Hz stimulation. B: At 10 Hz, NE depressed further the amplitude of LI-eIPSCs during the initial part of the response while it recovered at the end of the train. C: during 20 Hz, NE converted depression into facilitation, similar to low [Ca2+]o for LI-eIPSC. D and E: NE increased LII/III-eIPSCs amplitude conserving a depressing pattern at 5Hz (D) and at 10 Hz (E). F: NE increased LII/III-eIPSCs only for the first 4 responses of the 20 Hz pulse train.

Article Snippet: Electrically evoked IPSCs (eIPSCs) were measured by delivering trains of monophasic electric stimuli (ranges 90–180 μs, 10–50 μA) at 5, 10 or 20 Hz every 20 sec, with an isolation unit, through a glass stimulation monopolar electrode filled with ACSF, or with a concentric bipolar electrode (FHC Inc, ME), placed at about 100–200 μm lateral from the axis between the recorded neuron and the cortical neuropil, perpendicular to the latter, in either layer I (LI-eIPSCs), or layer II/III (LII/III-eIPSCs).

Techniques:

Journal:

Article Title: Dynamic modulation of short term synaptic plasticity in the auditory cortex: the role of norepinephrine

doi: 10.1016/j.heares.2010.08.014

Figure Lengend Snippet: Effect of NE on LI-eIPSCs. A: representative traces of synaptic responses evoked by 5 Hz in control (black) and NE (red). B: eIPSC amplitudes normalized to the amplitude of the first response (IPSCn/IPSC1). NE did not change normalized amplitudes. C and D: like A and B, but for 10 Hz stimulation, in control condition (black) and NE (red). D: IPSCs depression recovered at the end of the train (last 2 responses) in NE. E and F: like A and B, but for 20 Hz stimulation. E representative traces showing that NE (red) produced LI-eIPSCs facilitation throughout the whole pulse train while in control (black) only depression is present. F: IPSC normalized IPSC amplitude at 20 Hz. NE converted the depression in facilitation (n = 15).

Article Snippet: Electrically evoked IPSCs (eIPSCs) were measured by delivering trains of monophasic electric stimuli (ranges 90–180 μs, 10–50 μA) at 5, 10 or 20 Hz every 20 sec, with an isolation unit, through a glass stimulation monopolar electrode filled with ACSF, or with a concentric bipolar electrode (FHC Inc, ME), placed at about 100–200 μm lateral from the axis between the recorded neuron and the cortical neuropil, perpendicular to the latter, in either layer I (LI-eIPSCs), or layer II/III (LII/III-eIPSCs).

Techniques: Control, Produced

Journal:

Article Title: Dynamic modulation of short term synaptic plasticity in the auditory cortex: the role of norepinephrine

doi: 10.1016/j.heares.2010.08.014

Figure Lengend Snippet: Diagram representing the effect of the activation of noradrenergic receptors on inhibitory synapses in different layers at 20 Hz. A: LI-eIPSC. Diagram illustrating stimulation and recording site (left), effect of NE on the synapses (middle), on the GABAergic currents (upper right) and normalized amplitudes. NE decreases the absolute amplitude in the early part of the train, but increases the late amplitudes, converting a depressing into a facilitating response onto pyramidal cell apical dendrites. B: same as above but for LII/III-eIPSCs. NE increases the early absolute amplitudes and further decreases the amplitudes in the late part of the train. NE conserves and even increases its extent of synaptic depression onto the basal dendrites of the pyramidal cell.

Article Snippet: Electrically evoked IPSCs (eIPSCs) were measured by delivering trains of monophasic electric stimuli (ranges 90–180 μs, 10–50 μA) at 5, 10 or 20 Hz every 20 sec, with an isolation unit, through a glass stimulation monopolar electrode filled with ACSF, or with a concentric bipolar electrode (FHC Inc, ME), placed at about 100–200 μm lateral from the axis between the recorded neuron and the cortical neuropil, perpendicular to the latter, in either layer I (LI-eIPSCs), or layer II/III (LII/III-eIPSCs).

Techniques: Activation Assay