Effects of Noradrenaline on Frequency Tuning of Rat Auditory Cortex Neurons

Manunta, Yves; Edeline, Jean‐Marc

doi:10.1111/j.1460-9568.1997.tb01433.x

Cited by 105 publications

(106 citation statements)

References 50 publications

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Section: The Nb Cholinergic Systemmentioning

confidence: 99%

“…However, other neuromodulators affect the function of A1. For example, noradrenaline alters tuning 89,90 , serotonin can regulate intensity-dependent response functions 91 and its levels increase in A1 during initial stages of avoidance learning 92 , and dopamine is involved in the increased representation of a tone paired with stimulation of the VTA reward system 38 .The NB is the main source of cortical ACh 93,94 and there is extensive evidence for the importance of ACh and of the NB in particular in many aspects of learning (reviewed in REF. 33).…”

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confidence: 99%

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Specific long-term memory traces in primary auditory cortex

2004

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Learning and memory involve the storage of specific sensory experiences. However, until recently the idea that the primary sensory cortices could store specific memory traces had received little attention. Converging evidence obtained using techniques from sensory physiology and the neurobiology of learning and memory supports the idea that the primary auditory cortex acquires and retains specific memory traces about the behavioural significance of selected sounds. The cholinergic system of the nucleus basalis, when properly engaged, is sufficient to induce both specific memory traces and specific behavioural memory. A contemporary view of the primary auditory cortex should incorporate its mnemonic and other cognitive functions.Identifying the neural substrates of learning and memory is a core problem in neuroscience. As memories involve the representation of past sensory events, they may be stored, in part, within sensory systems. Sensory systems have traditionally been viewed as 'stimulus analysers', with learning and memory assigned to 'higher' cortical regions. Nonetheless, neurophysiological studies have produced evidence for learning-induced plasticity in sensory cortices, and in particular the auditory cortex. Galambos and colleagues first implicated the primary auditory cortex (A1) in learning in 1956, observing that pairing an auditory conditioned stimulus (CS) with a weak shock (a mildly aversive unconditioned stimulus (US)) produced a significant increase in the amplitude of CS-elicited evoked field potentials in A1 of the cat 1 . Subsequently, these findings were extended to other tasks (such as discrimination), types of learning (including instrumental conditioning), motivations (for example, food) and types of recording (such as single and multiple unit discharges) 2 .Although such results established associative plasticity in A1, neither they nor similar findings in other sensory cortices addressed the key issue of specificity of information storage. As memories have specific content, how could changes in the magnitude of sensory cortical responses adequately reflect the encoding of specific aspects of experiences? A solution was provided by the field of sensory neurophysiology, which focuses on stimulus specificity. Sensory physiology experiments use a wide range of stimulus values to NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript determine how specific sensory stimuli are processed and coded. In fact, the basic paradigms of sensory physiology and learning are complementary (Box 1).This article presents an overview of research that combines experimental designs from sensory physiology with those of learning and memory to search for specific memory traces in A1. A sign of a specific memory trace would be learning-induced physiological plasticity that has the key characteristics of behavioural memory and sufficient specificity to encode a canonical attribute of experience, such as a physical feature and its behavioural importance. Previous reviews have covered ot...

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Section: The Nb Cholinergic Systemmentioning

confidence: 99%

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confidence: 99%

Specific long-term memory traces in primary auditory cortex

2004

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“…As such, this study extends the idea that LC-mediated tonic release of NE can regulate postsynaptic neuronal responsiveness to synaptic inputs by revealing the inherent variability of these effects on individual cells, neighboring neurons, and local circuits along a sensory pathway. Evidence that LC output can simultaneously facilitate and suppress responses of individual neurons to somatosensory input and that modulatory effects are related to one another as a function of the level of LC efferent output begins to integrate discordant findings and opposing viewpoints regarding LC/NE suppression (Foote et al, 1975;Manunta and Edeline, 1997) versus absolute potentiation (Waterhouse and Woodward, 1980; Waterhouse et al, 1982Waterhouse et al, , 1990Waterhouse et al, , 1998Waterhouse et al, , 2000 of stimulus-evoked discharge. Figure 9.…”

Section: Present and Previous Findingsmentioning

confidence: 99%

“…As output from the LC increases, individual cells are suppressed and functionally removed from the pool of responsive neurons, while other neighboring neurons experience facilitation (and are functionally added to the responsive ensemble) over the same dynamic range of LC output. Such facilitation (Nawrot et al, 1999) and suppression (Manunta and Edeline, 1997) of sensory-responsive neurons in the functional ensemble may produce subtle, but important, changes in the sensory representation distributed across local populations of neurons.…”

Section: Present and Previous Findingsmentioning

confidence: 99%

The Effects of Tonic Locus Ceruleus Output on Sensory-Evoked Responses of Ventral Posterior Medial Thalamic and Barrel Field Cortical Neurons in the Awake Rat

Devilbiss¹,

Waterhouse²

2004

J. Neurosci.

145

111

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In mammals, the pontine nucleus locus ceruleus (LC) is the sole source of norepinephrine (NE) projections to the forebrain. Increasing tonic discharge of LC neurons elevates extracellular levels of NE in the cortex and thalamus. Tonic LC discharge is linked to the level of wakefulness and behavioral performance, demonstrating an optimal firing rate during sustained attention tasks. Iontophoretic application of NE to target neurons in the forebrain has been shown to produce a diverse set of neuromodulatory actions, including augmentation of synaptically evoked discharge as well as suppression of spontaneous and stimulus-evoked firing patterns. Iontophoretic studies cataloged potential NE effects; however, the context in which such actions could occur in awake behaving animals remained controversial. To address this issue, the current study examined the effects of increasing tonic LC output on spontaneous and stimulus-evoked discharge of neurons within the ventroposterior medial (VPM) thalamus and barrel field (BF) somatosensory cortex of awake animals using multichannel extracellular recording strategies. The present findings indicate two primary outcomes that result from increasing frequencies of LC stimulation, either an inverted-U facilitating response profile or monotonic suppression of sensory-evoked neuronal responses. Increased tonic LC output generally decreased neuronal response latency measures for both BF cortical and VPM thalamic cells. LC-mediated effects on target VPM and BF cortical neuron sensory processing are consistent with previous demonstrations of NE modulatory actions on central neurons but indicate that such actions are cell specific. Moreover, clear differences were observed between the modulation of VPM and BF cortical cells. These data suggest that sensory signal processing is continually altered over the range of tonic LC discharge frequencies that occur in the waking animal. Such changes may account for LC-mediated shifts in sensory network performance across multiple stages of arousal and attention.

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“…Neuromodulators typically have a diversity of effects among the neurons of a sensory neural circuit (for example, Rogawski and Aghajanian, 1980;Kossl and Vater, 1989;Ebert and Ostwald, 1992;Manunta and Edeline, 1997;Habbicht and Vater, 1996;Hurley et al, 2004). For a neuromodulator like serotonin, the effects of which are mediated by an exceptionally rich array of receptor types, understanding the roles played by these different receptors is especially significant.…”

Section: Introductionmentioning

confidence: 99%

Activation of the serotonin 1A receptor alters the temporal characteristics of auditory responses in the inferior colliculus

Hurley

2007

Brain Research

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Serotonin, like other neuromodulators, acts on a range of receptor types, but its effects also depend on the functional characteristics of the neurons responding to receptor activation. In the inferior colliculus (IC), an auditory midbrain nucleus, activation of a common serotonin (5-HT) receptor type, the 5-HT 1A receptor, depresses auditory-evoked responses in many neurons. Whether these effects occur differentially in different types of neurons is unknown. In the current study, the effects of iontophoretic application of the 5-HT 1A agonist 8-OH-DPAT on auditory responses were compared with the characteristic frequencies (CFs), recording depths, and control first-spike latencies of the same group of IC neurons. The 8-OH-DPAT-evoked change in response significantly correlated with first-spike latency across the population, so that response depressions were more prevalent in longer-latency neurons. The 8-OH-DPAT-evoked change in response did not correlate with CF or with recording depth. 8-OH-DPAT also altered the temporal characteristics of spike trains in a subset of neurons that fired multiple spikes in response to brief stimuli. For these neurons, activation of the 5-HT 1A receptor suppressed lagging spikes proportionally more than initial spikes. These results suggest that the 5-HT 1A receptor, by affecting the timing of the responses of both individual neurons and the neuron population, shifts the temporal profile of evoked activity within the IC.

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Effects of Noradrenaline on Frequency Tuning of Rat Auditory Cortex Neurons

Cited by 105 publications

References 50 publications

Specific long-term memory traces in primary auditory cortex

Specific long-term memory traces in primary auditory cortex

The Effects of Tonic Locus Ceruleus Output on Sensory-Evoked Responses of Ventral Posterior Medial Thalamic and Barrel Field Cortical Neurons in the Awake Rat

Activation of the serotonin 1A receptor alters the temporal characteristics of auditory responses in the inferior colliculus

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