Spectrotemporal Structure of Receptive Fields in Areas AI and AAF of Mouse Auditory Cortex

2003 ◽  
Vol 90 (4) ◽  
pp. 2660-2675 ◽  
Author(s):  
Jennifer F. Linden ◽  
Robert C. Liu ◽  
Maneesh Sahani ◽  
Christoph E. Schreiner ◽  
Michael M. Merzenich
Keyword(s):  
Receptive Field ◽  
Auditory Cortex ◽  
Receptive Fields ◽  
Primary Auditory Cortex ◽  
Dynamic Stimuli ◽  
Tuning Curves ◽  
Response Characteristics ◽  
Spectrotemporal Receptive Fields ◽  
Auditory Field ◽  
Tonal Stimuli

The mouse is a promising model system for auditory cortex research because of the powerful genetic tools available for manipulating its neural circuitry. Previous studies have identified two tonotopic auditory areas in the mouse—primary auditory cortex (AI) and anterior auditory field (AAF)— but auditory receptive fields in these areas have not yet been described. To establish a foundation for investigating auditory cortical circuitry and plasticity in the mouse, we characterized receptive-field structure in AI and AAF of anesthetized mice using spectrally complex and temporally dynamic stimuli as well as simple tonal stimuli. Spectrotemporal receptive fields (STRFs) were derived from extracellularly recorded responses to complex stimuli, and frequency-intensity tuning curves were constructed from responses to simple tonal stimuli. Both analyses revealed temporal differences between AI and AAF responses: peak latencies and receptive-field durations for STRFs and first-spike latencies for responses to tone bursts were significantly longer in AI than in AAF. Spectral properties of AI and AAF receptive fields were more similar, although STRF bandwidths were slightly broader in AI than in AAF. Finally, in both AI and AAF, a substantial minority of STRFs were spectrotemporally inseparable. The spectrotemporal interaction typically appeared in the form of clearly disjoint excitatory and inhibitory subfields or an obvious spectrotemporal slant in the STRF. These data provide the first detailed description of auditory receptive fields in the mouse and suggest that although neurons in areas AI and AAF share many response characteristics, area AAF may be specialized for faster temporal processing.

scholarly journals Dissociable influences of primary auditory cortex and the posterior auditory field on neuronal responses in the dorsal zone of auditory cortex

2015 ◽  
Vol 113 (2) ◽  
pp. 475-486
Author(s):  
Melanie A. Kok ◽  
Daniel Stolzberg ◽  
Trecia A. Brown ◽  
Stephen G. Lomber
Keyword(s):  
Auditory Cortex ◽  
Receptive Fields ◽  
Primary Auditory Cortex ◽  
Population Level ◽  
Noise Burst ◽  
Hierarchical Organization ◽  
Neuronal Responses ◽  
Tone Frequency ◽  
Hierarchical Processing ◽  
Auditory Field

Current models of hierarchical processing in auditory cortex have been based principally on anatomical connectivity while functional interactions between individual regions have remained largely unexplored. Previous cortical deactivation studies in the cat have addressed functional reciprocal connectivity between primary auditory cortex (A1) and other hierarchically lower level fields. The present study sought to assess the functional contribution of inputs along multiple stages of the current hierarchical model to a higher order area, the dorsal zone (DZ) of auditory cortex, in the anaesthetized cat. Cryoloops were placed over A1 and posterior auditory field (PAF). Multiunit neuronal responses to noise burst and tonal stimuli were recorded in DZ during cortical deactivation of each field individually and in concert. Deactivation of A1 suppressed peak neuronal responses in DZ regardless of stimulus and resulted in increased minimum thresholds and reduced absolute bandwidths for tone frequency receptive fields in DZ. PAF deactivation had less robust effects on DZ firing rates and receptive fields compared with A1 deactivation, and combined A1/PAF cooling was largely driven by the effects of A1 deactivation at the population level. These results provide physiological support for the current anatomically based model of both serial and parallel processing schemes in auditory cortical hierarchical organization.

scholarly journals Time Course of Forward Masking Tuning Curves in Cat Primary Auditory Cortex

1997 ◽  
Vol 77 (2) ◽  
pp. 923-943 ◽  
Author(s):  
Michael Brosch ◽  
Christoph E. Schreiner
Keyword(s):  
Receptive Field ◽  
Auditory Cortex ◽  
Stimulus Onset Asynchrony ◽  
Time Course ◽  
Tuning Curve ◽  
Primary Auditory Cortex ◽  
Stimulus Onset ◽  
Cortical Cells ◽  
Tuning Curves ◽  
Onset Asynchrony

Brosch, Michael and Christoph E. Schreiner. Time course of forward masking tuning curves in cat primary auditory cortex. J. Neurophysiol. 77: 923–943, 1997. Nonsimultaneous two-tone interactions were studied in the primary auditory cortex of anesthetized cats. Poststimulatory effects of pure tone bursts (masker) on the evoked activity of a fixed tone burst (probe) were investigated. The temporal interval from masker onset to probe onset (stimulus onset asynchrony), masker frequency, and intensity were parametrically varied. For all of the 53 single units and 58 multiple-unit clusters, the neural activity of the probe signal was either inhibited, facilitated, and/or delayed by a limited set of masker stimuli. The stimulus range from which forward inhibition of the probe was induced typically was centered at and had approximately the size of the neuron's excitatory receptive field. This “masking tuning curve” was usually V shaped, i.e., the frequency range of inhibiting masker stimuli increased with the masker intensity. Forward inhibition was induced at the shortest stimulus onset asynchrony between masker and probe. With longer stimulus onset asynchronies, the frequency range of inhibiting maskers gradually became smaller. Recovery from forward inhibition occurred first at the lower- and higher-frequency borders of the masking tuning curve and lasted the longest for frequencies close to the neuron's characteristic frequency. The maximal duration of forward inhibition was measured as the longest period over which reduction of probe responses was observed. It was in the range of 53–430 ms, with an average of 143 ± 71 (SD) ms. Amount, duration and type of forward inhibition were weakly but significantly correlated with “static” neural receptive field properties like characteristic frequency, bandwidth, and latency. For the majority of neurons, the minimal inhibitory masker intensity increased when the stimulus onset asynchrony became longer. In most cases the highest masker intensities induced the longest forward inhibition. A significant number of neurons, however, exhibited longest periods of inhibition after maskers of intermediate intensity. The results show that the ability of cortical cells to respond with an excitatory activity depends on the temporal stimulus context. Neurons can follow higher repetition rates of stimulus sequences when successive stimuli differ in their spectral content. The differential sensitivity to temporal sound sequences within the receptive field of cortical cells as well as across different cells could contribute to the neural processing of temporally structured stimuli like speech and animal vocalizations.

Frequency-Modulation Encoding in the Primary Auditory Cortex of the Awake Owl Monkey

2007 ◽  
Vol 98 (4) ◽  
pp. 2182-2195 ◽  
Author(s):  
Craig A. Atencio ◽  
David T. Blake ◽  
Fabrizio Strata ◽  
Steven W. Cheung ◽  
Michael M. Merzenich ◽  
...  
Keyword(s):  
Auditory Cortex ◽  
World Monkey ◽  
Receptive Fields ◽  
Primary Auditory Cortex ◽  
Direction Selectivity ◽  
Neural Responses ◽  
Population Distributions ◽  
Spectrotemporal Receptive Fields ◽  
Owl Monkey ◽  
Highly Correlated

Many communication sounds, such as New World monkey twitter calls, contain frequency-modulated (FM) sweeps. To determine how this prominent vocalization element is represented in the auditory cortex we examined neural responses to logarithmic FM sweep stimuli in the primary auditory cortex (AI) of two awake owl monkeys. Using an implanted array of microelectrodes we quantitatively characterized neuronal responses to FM sweeps and to random tone-pip stimuli. Tone-pip responses were used to construct spectrotemporal receptive fields (STRFs). Classification of FM sweep responses revealed few neurons with high direction and speed selectivity. Most neurons responded to sweeps in both directions and over a broad range of sweep speeds. Characteristic frequency estimates from FM responses were highly correlated with estimates from STRFs, although spectral receptive field bandwidth was consistently underestimated by FM stimuli. Predictions of FM direction selectivity and best speed from STRFs were significantly correlated with observed FM responses, although some systematic discrepancies existed. Last, the population distributions of FM responses in the awake owl monkey were similar to, although of longer temporal duration than, those in the anesthetized squirrel monkeys.

scholarly journals Laminar Diversity of Dynamic Sound Processing in Cat Primary Auditory Cortex

2010 ◽  
Vol 103 (1) ◽  
pp. 192-205 ◽  
Author(s):  
Craig A. Atencio ◽  
Christoph E. Schreiner
Keyword(s):  
Auditory Cortex ◽  
Transfer Functions ◽  
Receptive Fields ◽  
Primary Auditory Cortex ◽  
Functional Characteristic ◽  
Modulation Transfer ◽  
Spectral Modulation ◽  
Spectrotemporal Receptive Fields ◽  
Low Pass ◽  
Acoustic Modulation

For primary auditory cortex (AI) laminae, there is little evidence of functional specificity despite clearly expressed cellular and connectional differences. Natural sounds are dominated by dynamic temporal and spectral modulations and we used these properties to evaluate local functional differences or constancies across laminae. To examine the layer-specific processing of acoustic modulation information, we simultaneously recorded from multiple AI laminae in the anesthetized cat. Neurons were challenged with dynamic moving ripple stimuli and we subsequently computed spectrotemporal receptive fields (STRFs). From the STRFs, temporal and spectral modulation transfer functions (tMTFs, sMTFs) were calculated and compared across layers. Temporal and spectral modulation properties often differed between layers. On average, layer II/III and VI neurons responded to lower temporal modulations than those in layer IV. tMTFs were mainly band-pass in granular layer IV and became more low-pass in infragranular layers. Compared with layer IV, spectral MTFs were broader and their upper cutoff frequencies higher in layers V and VI. In individual penetrations, temporal modulation preference was similar across layers for roughly 70% of the penetrations, suggesting a common, columnar functional characteristic. By contrast, only about 30% of penetrations showed consistent spectral modulation preferences across layers, indicative of functional laminar diversity or specialization. Since local laminar differences in stimulus preference do not always parallel the main flow of information in the columnar cortical microcircuit, this indicates the influence of additional horizontal or thalamocortical inputs. AI layers that express differing modulation properties may serve distinct roles in the extraction of dynamic sound information, with the differing information specific to the targeted stations of each layer.

scholarly journals Spectrotemporal Receptive Fields in Anesthetized Cat Primary Auditory Cortex Are Context Dependent

2008 ◽  
Vol 19 (6) ◽  
pp. 1448-1461 ◽  
Author(s):  
Boris Gourévitch ◽  
Arnaud Noreña ◽  
Gregory Shaw ◽  
Jos J. Eggermont
Keyword(s):  
Auditory Cortex ◽  
Receptive Fields ◽  
Primary Auditory Cortex ◽  
Spectrotemporal Receptive Fields ◽  
Context Dependent ◽  
Anesthetized Cat

scholarly journals Comparison of responses in the anterior and primary auditory fields of the ferret cortex

1995 ◽  
Vol 73 (4) ◽  
pp. 1513-1523 ◽  
Author(s):  
N. Kowalski ◽  
H. Versnel ◽  
S. A. Shamma
Keyword(s):  
Auditory Cortex ◽  
Weighted Average ◽  
Primary Auditory Cortex ◽  
Directional Sensitivity ◽  
High Frequencies ◽  
Electrophysiological Responses ◽  
Range Rate ◽  
Auditory Field ◽  
The Relationship ◽  
Tonal Stimuli

1. Characteristics of an anterior auditory field (AAF) in the ferret auditory cortex are described in terms of its electrophysiological responses to tonal stimuli and compared with those of primary auditory cortex (AI). Ferrets were barbiturate-anesthetized and tungsten microelectrodes were used to record single-unit responses from both AI and AAF fields. Units in both areas were presented with the same stimulus paradigms and their responses analyzed in the same manner so that a direct comparison of responses was possible. 2. The AAF is located dorsal and rostral to AI on the ectosylvian gyrus and extends into the suprasylvian sulcus rostral to AI. The tonotopicity is organized with high frequencies at the top of the sulcus bordering the high-frequency area of AI, then reversing with lower BFs extending down into the sulcus. AAF contained single units that responded to a frequency range of 0.3-30 kHz. 3. Stimuli consisted of single-tone bursts, two-tone bursts and frequency-modulated (FM) stimuli swept in both directions at various rates. Best frequency (BF) range, rate-level functions at BF, FM directional sensitivity, and variation in asymmetries of response areas were all comparable characteristics between AAF and AI. Responses in both areas were primarily phasic. 4. The characteristics that were different between the two cortical areas were: latency to tone onset, excitatory bandwidth 20 dB above threshold (BW20), and preferred FM rate as parameterized with the centroid (a weighted average of spike counts). The mean latency of AAF units was shorter than in AI (AAF: 16.8 ms, AI: 19.4 ms). BW20 measurements in AAF were typically twice as large as those found in AI (AAF: 2.5 octaves, AI 1.3 octaves). The AI centroid population had a significantly larger standard deviation than the AAF centroid population. 5. We examined the relationship between centroid and BW20 to see whether wider bandwidths were a factor in a unit's ability to detect fast sweeps. There was significant (P < 0.05) linear correlation in AAF but not in AI. In both fields the variance of the centroid population decreased with increasing BW20. BW20 decreased as BF increased for units in both auditory fields.

Intracortical Pathways Determine Breadth of Subthreshold Frequency Receptive Fields in Primary Auditory Cortex

2004 ◽  
Vol 91 (6) ◽  
pp. 2551-2567 ◽  
Author(s):  
Simranjit Kaur ◽  
Ronit Lazar ◽  
Raju Metherate
Keyword(s):  
Receptive Field ◽  
Auditory Cortex ◽  
Receptive Fields ◽  
Field Potential ◽  
Primary Auditory Cortex ◽  
Response Threshold ◽  
Complex Stimuli ◽  
Cortical Receptive Fields ◽  
Local Field Potential Lfp ◽  
Integrated Responses

To examine the basis of frequency receptive fields in auditory cortex (ACx), we have recorded intracellular (whole cell) and extracellular (local field potential, LFP) responses to tones in anesthetized rats. Frequency receptive fields derived from excitatory postsynaptic potentials (EPSPs) and LFPs from the same location resembled each other in terms of characteristic frequency (CF) and breadth of tuning, suggesting that LFPs reflect local synaptic (including subthreshold) activity. Subthreshold EPSP and LFP receptive fields were remarkably broad, often spanning five octaves (the maximum tested) at moderate intensities (40–50 dB above threshold). To identify receptive-field features that are generated intracortically, we microinjected the GABAA receptor agonist muscimol (0.2–5.1 mM, 1–5 μl) into ACx. Muscimol dramatically reduced LFP amplitude and reduced receptive-field bandwidth, implicating intracortical contributions to these features but had lesser effects on CF response threshold or onset latency, suggesting minimal loss of thalamocortical input. Reversal of muscimol's inhibition preferentially at the recording site by diffusion from the recording pipette of the GABAA receptor antagonist picrotoxin (0.01–100 μM) disinhibited responses to CF stimuli more than responses to spectrally distant, non-CF stimuli. We propose that thalamocortical and intracortical pathways preferentially contribute to responses evoked by CF and non-CF stimuli, respectively, and that intracortical projections linking frequency representations determine the breadth of receptive fields in primary ACx. Broad, subthreshold receptive fields may distinguish ACx from subcortical auditory relay nuclei, promote integrated responses to spectrotemporally complex stimuli, and provide a substrate for plasticity of cortical receptive fields and maps.

scholarly journals Network Architecture, Receptive Fields, and Neuromodulation: Computational and Functional Implications of Cholinergic Modulation in Primary Auditory Cortex

2006 ◽  
Vol 96 (6) ◽  
pp. 2972-2983 ◽  
Author(s):  
Gabriel Soto ◽  
Nancy Kopell ◽  
Kamal Sen
Keyword(s):  
Auditory Cortex ◽  
Cortical Neurons ◽  
Network Architecture ◽  
Frequency Tuning ◽  
Receptive Fields ◽  
Primary Auditory Cortex ◽  
Physiological Data ◽  
Cholinergic Modulation ◽  
Tuning Curves ◽  
Intracortical Circuits

Two fundamental issues in auditory cortical processing are the relative importance of thalamocortical versus intracortical circuits in shaping response properties in primary auditory cortex (ACx), and how the effects of neuromodulators on these circuits affect dynamic changes in network and receptive field properties that enhance signal processing and adaptive behavior. To investigate these issues, we developed a computational model of layers III and IV (LIII/IV) of AI, constrained by anatomical and physiological data. We focus on how the local and global cortical architecture shape receptive fields (RFs) of cortical cells and on how different well-established cholinergic effects on the cortical network reshape frequency-tuning properties of cells in ACx. We identify key thalamocortical and intracortical circuits that strongly affect tuning curves of model cortical neurons and are also sensitive to cholinergic modulation. We then study how differential cholinergic modulation of network parameters change the tuning properties of our model cells and propose two different mechanisms: one intracortical (involving muscarinic receptors) and one thalamocortical (involving nicotinic receptors), which may be involved in rapid plasticity in ACx, as recently reported in a study by Fritz and coworkers.

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