Journal of Neurophysiology

E. S. Albert , J. M. Bec , G. Desmadryl , K. Chekroud , C. Travo , S. Gaboyard , F. Bardin , I. Marc , M. Dumas , G. Lenaers , C. Hamel , A. Muller , and C. Chabbert

doi: 10.1152/jn.00424.2011pmid: 22442563

Infrared laser irradiation has been established as an appropriate stimulus for primary sensory neurons under conditions where sensory receptor cells are impaired or lost. Yet, development of clinical applications has been impeded by lack of information about the molecular mechanisms underlying the laser-induced neural response. Here, we directly address this question through pharmacological characterization of the biological response evoked by midinfrared irradiation of isolated retinal and vestibular ganglion cells from rodents. Whole cell patch-clamp recordings reveal that both voltage-gated calcium and sodium channels contribute to the laser-evoked neuronal voltage variations (LEVV). In addition, selective blockade of the LEVV by micromolar concentrations of ruthenium red and RN 1734 identifies thermosensitive transient receptor potential vanilloid channels as the primary effectors of the chain reaction triggered by midinfrared laser irradiation. These results have the potential to facilitate greatly the design of future prosthetic devices aimed at restoring neurosensory capacities in disabled patients. transient receptor potential vanilloid 4 prosthesis Copyright © 2012 the American Physiological Society « Previous | Next Article » Table of Contents This Article Published online before print March 21, 2012 , doi: 10.​1152/​jn.​00424.​2011 AJP - JN Physiol June 15, 2012 vol. 107 no. 12 3227-3234 » Abstract Free Full Text Full Text (PDF) All Versions of this Article: jn.00424.2011v1 107/12/3227 most recent Classifications Article Services Email this article to a friend Alert me when this article is cited Alert me if a correction is posted Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Download to citation manager Citing Articles Load citing article information Citing articles via Web of Science Google Scholar Articles by Albert, E. S. Articles by Chabbert, C. PubMed PubMed citation Articles by Albert, E. S. Articles by Chabbert, C. Related Content Load related web page information Current Content June 15, 2012 Alert me to new issues of AJP - JN Physiol About the Journal Calls for Papers Information for Authors Submit a Manuscript Ethical Policies AuthorChoice PubMed Central Policy Reprints and Permissions Advertising Press Copyright © 2012 the American Physiological Society Print ISSN: 0022-3077 Online ISSN: 1522-1598

Thomas J. Foutz , Richard L. Arlow , and Cameron C. McIntyre

doi: 10.1152/jn.00501.2011pmid: 22442566

Optogenetics is an emerging field of neuromodulation that permits scaled, millisecond temporal control of the membrane dynamics of genetically targeted cells using light. Optogenetic technology has revolutionized neuroscience research; however, numerous biophysical questions remain on the optical and neuronal factors impacting the modulation of neural activity with photon-sensitive ion channels. To begin to address such questions, we developed a computational tool to explore the underlying principles of optogenetic neural stimulation. This “light-neuron” model consists of theoretical representations of the light dynamics generated by a fiber optic in brain tissue, coupled to a multicompartment cable model of a cortical pyramidal neuron embedded with channelrhodopsin-2 (ChR2) membrane dynamics. Simulations revealed that the large energies required to generate an action potential are primarily due to the limited conductivity of ChR2, and that the major determinants of stimulation threshold are the surface area of illuminated cell membrane and proximity to the light source. Our results predict that the activation threshold is sensitive to many of the properties of ChR2 (density, conductivity, and kinetics), tissue medium (scattering and absorbance), and the fiber-optic light source (diameter and numerical aperture). We also illustrate the impact of redistributing the ChR2 expression density (uniform vs. nonuniform) on the activation threshold. The model system developed in this study represents a scientific instrument to characterize the effects of optogenetic neuromodulation, as well as an engineering design tool to help guide future development of optogenetic technology. neuromodulation computer model optogenetic fiber optic Copyright © 2012 the American Physiological Society « Previous | Next Article » Table of Contents This Article Published online before print March 21, 2012 , doi: 10.​1152/​jn.​00501.​2011 AJP - JN Physiol June 15, 2012 vol. 107 no. 12 3235-3245 » Abstract Free Full Text Full Text (PDF) All Versions of this Article: jn.00501.2011v1 107/12/3235 most recent Classifications Article Services Email this article to a friend Alert me when this article is cited Alert me if a correction is posted Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Download to citation manager Citing Articles Load citing article information Citing articles via Web of Science Google Scholar Articles by Foutz, T. J. Articles by McIntyre, C. C. PubMed PubMed citation Articles by Foutz, T. J. Articles by McIntyre, C. C. Related Content Load related web page information Current Content June 15, 2012 Alert me to new issues of AJP - JN Physiol About the Journal Calls for Papers Information for Authors Submit a Manuscript Ethical Policies AuthorChoice PubMed Central Policy Reprints and Permissions Advertising Press Copyright © 2012 the American Physiological Society Print ISSN: 0022-3077 Online ISSN: 1522-1598

Michael Campos , Kari Koppitch , Richard A. Andersen , and Shinsuke Shimojo

doi: 10.1152/jn.00690.2010pmid: 22423007

Neurons in the orbitofrontal cortex (OFC) have been shown to encode subjective values, suggesting a role in preference-based decision-making, although the precise relation to choice behavior is unclear. In a repeated two-choice task, subjective values of each choice can account for aggregate choice behavior, which is the overall likelihood of choosing one option over the other. Individual choices, however, are impossible to predict with knowledge of relative subjective values alone. In this study we investigated the role of internal factors in choice behavior with a simple but novel free-choice task and simultaneous recording from individual neurons in nonhuman primate OFC. We found that, first, the observed sequences of choice behavior included periods of exceptionally long runs of each of two available options and periods of frequent switching. Neither a satiety-based mechanism nor a random selection process could explain the observed choice behavior. Second, OFC neurons encode important features of the choice behavior. These features include activity selective for exceptionally long runs of a given choice (stay selectivity) as well as activity selective for switches between choices (switch selectivity). These results suggest that OFC neural activity, in addition to encoding subjective values on a long timescale that is sensitive to satiety, also encodes a signal that fluctuates on a shorter timescale and thereby reflects some of the statistically improbable aspects of free-choice behavior. action selection frontal cortex reward preferences monkey Copyright © 2012 the American Physiological Society « Previous | Next Article » Table of Contents This Article Published online before print March 14, 2012 , doi: 10.​1152/​jn.​00690.​2010 AJP - JN Physiol June 15, 2012 vol. 107 no. 12 3246-3255 » Abstract Free Full Text Free to you Full Text (PDF) Free to you All Versions of this Article: jn.00690.2010v1 107/12/3246 most recent Classifications Article Services Email this article to a friend Alert me when this article is cited Alert me if a correction is posted Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Download to citation manager Citing Articles Load citing article information Citing articles via Web of Science Google Scholar Articles by Campos, M. Articles by Shimojo, S. PubMed PubMed citation Articles by Campos, M. Articles by Shimojo, S. Related Content Load related web page information Current Content June 15, 2012 Alert me to new issues of AJP - JN Physiol About the Journal Calls for Papers Information for Authors Submit a Manuscript Ethical Policies AuthorChoice PubMed Central Policy Reprints and Permissions Advertising Press Copyright © 2012 the American Physiological Society Print ISSN: 0022-3077 Online ISSN: 1522-1598

Jason Dyck , Guillermo M. Lanuza , and Simon Gosgnach

doi: 10.1152/jn.01132.2011pmid: 22442567

Our understanding of the neural control of locomotion has been greatly enhanced by the ability to identify and manipulate genetically defined populations of interneurons that comprise the locomotor central pattern generator (CPG). To date, the dI6 interneurons are one of the few populations that settle in the ventral region of the postnatal spinal cord that have not been investigated. In the present study, we utilized a novel transgenic mouse line to electrophysiologically characterize dI6 interneurons located close to the central canal and study their function during fictive locomotion. The majority of dI6 cells investigated were found to be rhythmically active during fictive locomotion and could be divided into two electrophysiologically distinct populations of interneurons. The first population fired rhythmic trains of action potentials that were loosely coupled to ventral root output and contained several intrinsic membrane properties of rhythm-generating neurons, raising the possibility that these cells may be involved in the generation of rhythmic activity in the locomotor CPG. The second population fired rhythmic trains of action potentials that were tightly coupled to ventral root output and lacked intrinsic oscillatory mechanisms, indicating that these neurons may be driven by a rhythm-generating network. Together these results indicate that dI6 neurons comprise an important component of the locomotor CPG that participate in multiple facets of motor behavior. central pattern generator neural circuit Copyright © 2012 the American Physiological Society « Previous | Next Article » Table of Contents This Article Published online before print March 21, 2012 , doi: 10.​1152/​jn.​01132.​2011 AJP - JN Physiol June 15, 2012 vol. 107 no. 12 3256-3266 » Abstract Free Full Text Full Text (PDF) All Versions of this Article: jn.01132.2011v1 107/12/3256 most recent Classifications Article Services Email this article to a friend Alert me when this article is cited Alert me if a correction is posted Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Download to citation manager Citing Articles Load citing article information Citing articles via Web of Science Google Scholar Articles by Dyck, J. Articles by Gosgnach, S. PubMed PubMed citation Articles by Dyck, J. Articles by Gosgnach, S. Related Content Load related web page information Current Content June 15, 2012 Alert me to new issues of AJP - JN Physiol About the Journal Calls for Papers Information for Authors Submit a Manuscript Ethical Policies AuthorChoice PubMed Central Policy Reprints and Permissions Advertising Press Copyright © 2012 the American Physiological Society Print ISSN: 0022-3077 Online ISSN: 1522-1598

T. I. Tóth , S. Knops , and S. Daun-Gruhn

doi: 10.1152/jn.01124.2011pmid: 22402652

The mechanism underlying the generation of stepping has been the object of intensive studies. Stepping involves the coordinated movement of different leg joints and is, in the case of insects, produced by antagonistic muscle pairs. In the stick insect, the coordinated actions of three such antagonistic muscle pairs produce leg movements and determine the stepping pattern of the limb. The activity of the muscles is controlled by the nervous system as a whole and more specifically by local neuronal networks for each muscle pair. While many basic properties of these control mechanisms have been uncovered, some important details of their interactions in various physiological conditions have so far remained unknown. In this study, we present a neuromechanical model of the coupled protractor-retractor and levator-depressor neuromuscular systems and use it to elucidate details of their coordinated actions during forward and backward walking. The switch from protraction to retraction is evoked at a critical angle of the femur during downward movement. This angle represents a sensory input that integrates load, motion, and ground contact. Using the model, we can make detailed suggestions as to how rhythmic stepping might be generated by the central pattern generators of the local neuronal networks, how this activity might be transmitted to the corresponding motoneurons, and how the latter might control the activity of the related muscles. The entirety of these processes yields the coordinated interaction between neuronal and mechanical parts of the system. Moreover, we put forward a mechanism by which motoneuron activity could be modified by a premotor network and suggest that this mechanism might serve as a basis for fast adaptive behavior, like switches between forward and backward stepping, which occur, for example, during curve walking, and especially sharp turning, of insects. central pattern generators locomotion motor systems neuronal control simulation Copyright © 2012 the American Physiological Society « Previous | Next Article » Table of Contents This Article Published online before print March 7, 2012 , doi: 10.​1152/​jn.​01124.​2011 AJP - JN Physiol June 15, 2012 vol. 107 no. 12 3267-3280 » Abstract Free Full Text Free to you Full Text (PDF) Free to you Supplemental Videos All Versions of this Article: jn.01124.2011v1 107/12/3267 most recent Classifications Article Services Email this article to a friend Alert me when this article is cited Alert me if a correction is posted Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Download to citation manager Citing Articles Load citing article information Citing articles via Web of Science Google Scholar Articles by Tóth, T. I. Articles by Daun-Gruhn, S. PubMed PubMed citation Articles by Tóth, T. I. Articles by Daun-Gruhn, S. Related Content Load related web page information Current Content June 15, 2012 Alert me to new issues of AJP - JN Physiol About the Journal Calls for Papers Information for Authors Submit a Manuscript Ethical Policies AuthorChoice PubMed Central Policy Reprints and Permissions Advertising Press Copyright © 2012 the American Physiological Society Print ISSN: 0022-3077 Online ISSN: 1522-1598

Yuzhi Chen , Chris R. Palmer , and Eyal Seidemann

doi: 10.1152/jn.00977.2011pmid: 22422999

Voltage-sensitive dye imaging (VSDI) is a powerful technique for measuring neural population responses from a large cortical region simultaneously with millisecond temporal resolution and columnar spatial resolution. However, the relationship between the average VSDI signal and the average spiking activity of neural populations is largely unknown. To better understand this relationship, we compared visual responses measured from V1 of behaving monkeys using VSDI and single-unit electrophysiology. We found large and systematic differences between position and orientation tuning properties obtained with these two techniques. We then determined that a simple computational model could explain these tuning differences. This model, together with our experimental results, allowed us to estimate the quantitative relationship between the average VSDI signal and local spiking activity. We found that this relationship is similar to the previously reported nonlinear relationship between average membrane potential and spike rate in single V1 neurons, suggesting that VSDI signals are dominated by subthreshold synaptic activity. This model, together with the VSDI measured maps for spatial position (retinotopy) and orientation, also allowed us to estimate the spatial integration area over which neural responses contribute to the VSDI signal at a given location. We found that the VSDI-integration area is consistent with a Gaussian envelope with a space constant of ∼230 μm. Finally, we show how this model and estimated parameters can be used to predict the pattern of population responses at the level of spiking activity from VSDI responses. nonlinear transfer function spatial integration topographic maps mammalian cortex Copyright © 2012 the American Physiological Society « Previous | Next Article » Table of Contents This Article Published online before print March 14, 2012 , doi: 10.​1152/​jn.​00977.​2011 AJP - JN Physiol June 15, 2012 vol. 107 no. 12 3281-3295 » Abstract Free Full Text Free to you Full Text (PDF) Free to you All Versions of this Article: jn.00977.2011v1 107/12/3281 most recent Classifications Article Services Email this article to a friend Alert me when this article is cited Alert me if a correction is posted Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Download to citation manager Citing Articles Load citing article information Citing articles via Web of Science Google Scholar Articles by Chen, Y. Articles by Seidemann, E. PubMed PubMed citation Articles by Chen, Y. Articles by Seidemann, E. Related Content Load related web page information Current Content June 15, 2012 Alert me to new issues of AJP - JN Physiol About the Journal Calls for Papers Information for Authors Submit a Manuscript Ethical Policies AuthorChoice PubMed Central Policy Reprints and Permissions Advertising Press Copyright © 2012 the American Physiological Society Print ISSN: 0022-3077 Online ISSN: 1522-1598

Nadja Schinkel-Bielefeld , Stephen V. David , Shihab A. Shamma , and Daniel A. Butts

doi: 10.1152/jn.01173.2011pmid: 22457454

Intracellular studies have revealed the importance of cotuned excitatory and inhibitory inputs to neurons in auditory cortex, but typical spectrotemporal receptive field models of neuronal processing cannot account for this overlapping tuning. Here, we apply a new nonlinear modeling framework to extracellular data recorded from primary auditory cortex (A1) that enables us to explore how the interplay of excitation and inhibition contributes to the processing of complex natural sounds. The resulting description produces more accurate predictions of observed spike trains than the linear spectrotemporal model, and the properties of excitation and inhibition inferred by the model are furthermore consistent with previous intracellular observations. It can also describe several nonlinear properties of A1 that are not captured by linear models, including intensity tuning and selectivity to sound onsets and offsets. These results thus offer a broader picture of the computational role of excitation and inhibition in A1 and support the hypothesis that their interactions play an important role in the processing of natural auditory stimuli. model nonlinear audition cortex Copyright © 2012 the American Physiological Society « Previous | Next Article » Table of Contents This Article Published online before print March 28, 2012 , doi: 10.​1152/​jn.​01173.​2011 AJP - JN Physiol June 15, 2012 vol. 107 no. 12 3296-3307 » Abstract Free Full Text Free to you Full Text (PDF) Free to you All Versions of this Article: jn.01173.2011v1 107/12/3296 most recent Classifications Article Services Email this article to a friend Alert me when this article is cited Alert me if a correction is posted Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Download to citation manager Citing Articles Load citing article information Citing articles via Web of Science Google Scholar Articles by Schinkel-Bielefeld, N. Articles by Butts, D. A. PubMed PubMed citation Articles by Schinkel-Bielefeld, N. Articles by Butts, D. A. Related Content Load related web page information Current Content June 15, 2012 Alert me to new issues of AJP - JN Physiol About the Journal Calls for Papers Information for Authors Submit a Manuscript Ethical Policies AuthorChoice PubMed Central Policy Reprints and Permissions Advertising Press Copyright © 2012 the American Physiological Society Print ISSN: 0022-3077 Online ISSN: 1522-1598

Brian E. Cairns , Xu-Dong Dong , Hayes Wong , and Peter Svensson

doi: 10.1152/jn.01118.2011pmid: 22402656

The nonsteroidal anti-inflammatory drug (NSAID) diclofenac has local anesthetic-like and peripheral N -methyl- d -aspartate (NMDA) receptor antagonist characteristics when administered at higher concentrations to masticatory muscle. It is not known if the ability to inhibit NMDA receptors is unique to diclofenac or shared by other NSAIDs. This study was undertaken to determine whether intramuscular injection of ketorolac or naproxen at concentrations that do not induce local anesthetic-like effects could attenuate jaw-closer muscle nociceptor discharge in anesthetized Sprague-Dawley rats. It was found that ketorolac (5 mM) inhibited hypertonic saline-evoked nociceptor discharge, which suggests that at this concentration, ketorolac has local anesthetic-like properties. A lower concentration of ketorolac (0.5 mM), which did not affect hypertonic saline-evoked discharge, did inhibit nociceptor discharge evoked by NMDA. In contrast, naproxen (5 mM) did not alter hypertonic saline- or NMDA-evoked nociceptor discharge. Subsequent experiments revealed that ketorolac (0.5 mM) had no effect on nociceptor discharge evoked by αβ-methylene ATP, 5-hydroxytryptamine, or AMPA. The inhibitory effect of ketorolac did not appear to be related to cyclooxygenase inhibition, because the concentration of prostaglandin E 2 in the masticatory muscles 10 min after injection of either NSAID was not significantly decreased. The present study indicates that in vivo, ketorolac, but not naproxen, can antagonize NMDA-evoked nociceptor discharge similarly to diclofenac. We speculate that structural similarities between ketorolac and diclofenac could account for the ability of these NSAIDs to inhibit NMDA-evoked nociceptor discharge. These properties may partly explain the analgesic effect of intramuscularly injected ketorolac in the clinic. masseter muscle N -methyl- d -aspartate receptor pain trigeminal Copyright © 2012 the American Physiological Society « Previous | Next Article » Table of Contents This Article Published online before print March 7, 2012 , doi: 10.​1152/​jn.​01118.​2011 AJP - JN Physiol June 15, 2012 vol. 107 no. 12 3308-3315 » Abstract Free Full Text Free to you Full Text (PDF) Free to you All Versions of this Article: jn.01118.2011v1 107/12/3308 most recent Classifications Article Services Email this article to a friend Alert me when this article is cited Alert me if a correction is posted Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Download to citation manager Citing Articles Load citing article information Citing articles via Web of Science Google Scholar Articles by Cairns, B. E. Articles by Svensson, P. PubMed PubMed citation Articles by Cairns, B. E. Articles by Svensson, P. Related Content Load related web page information Current Content June 15, 2012 Alert me to new issues of AJP - JN Physiol About the Journal Calls for Papers Information for Authors Submit a Manuscript Ethical Policies AuthorChoice PubMed Central Policy Reprints and Permissions Advertising Press Copyright © 2012 the American Physiological Society Print ISSN: 0022-3077 Online ISSN: 1522-1598

Stephanie A. H. Jones , Patrick A. Byrne , Katja Fiehler , and Denise Y. P. Henriques

doi: 10.1152/jn.00901.2011pmid: 22402658

Previous research has shown that reach endpoints vary with the starting position of the reaching hand and the location of the reach target in space. We examined the effect of movement direction of a proprioceptive target-hand, immediately preceding a reach, on reach endpoints to that target. Participants reached to visual, proprioceptive (left target-hand), or visual-proprioceptive targets (left target-hand illuminated for 1 s prior to reach onset) with their right hand. Six sites served as starting and final target locations (35 target movement directions in total). Reach endpoints do not vary with the movement direction of the proprioceptive target, but instead appear to be anchored to some other reference (e.g., body). We also compared reach endpoints across the single and dual modality conditions. Overall, the pattern of reaches for visual-proprioceptive targets resembled those for proprioceptive targets, while reach precision resembled those for the visual targets. We did not, however, find evidence for integration of vision and proprioception based on a maximum-likelihood estimator in these tasks. maximum-likelihood estimator integration proprioceptive target-hand Copyright © 2012 the American Physiological Society « Previous | Next Article » Table of Contents This Article Published online before print March 7, 2012 , doi: 10.​1152/​jn.​00901.​2011 AJP - JN Physiol June 15, 2012 vol. 107 no. 12 3316-3324 » Abstract Free Full Text Free to you Full Text (PDF) Free to you All Versions of this Article: jn.00901.2011v1 107/12/3316 most recent Classifications Article Services Email this article to a friend Alert me when this article is cited Alert me if a correction is posted Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Download to citation manager Citing Articles Load citing article information Citing articles via Web of Science Google Scholar Articles by Jones, S. A. H. Articles by Henriques, D. Y. P. PubMed PubMed citation Articles by Jones, S. A. H. Articles by Henriques, D. Y. P. Related Content Load related web page information Current Content June 15, 2012 Alert me to new issues of AJP - JN Physiol About the Journal Calls for Papers Information for Authors Submit a Manuscript Ethical Policies AuthorChoice PubMed Central Policy Reprints and Permissions Advertising Press Copyright © 2012 the American Physiological Society Print ISSN: 0022-3077 Online ISSN: 1522-1598

Jeffrey S. Johnson , Pingbo Yin , Kevin N. O'Connor , and Mitchell L. Sutter

doi: 10.1152/jn.00812.2011pmid: 22422997

Amplitude modulation (AM) is a common feature of natural sounds, and its detection is biologically important. Even though most sounds are not fully modulated, the majority of physiological studies have focused on fully modulated (100% modulation depth) sounds. We presented AM noise at a range of modulation depths to awake macaque monkeys while recording from neurons in primary auditory cortex (A1). The ability of neurons to detect partial AM with rate and temporal codes was assessed with signal detection methods. On average, single-cell synchrony was as or more sensitive than spike count in modulation detection. Cells are less sensitive to modulation depth if tested away from their best modulation frequency, particularly for temporal measures. Mean neural modulation detection thresholds in A1 are not as sensitive as behavioral thresholds, but with phase locking the most sensitive neurons are more sensitive, suggesting that for temporal measures the lower-envelope principle cannot account for thresholds. Three methods of preanalysis pooling of spike trains (multiunit, similar to convergence from a cortical column; within cell, similar to convergence of cells with matched response properties; across cell, similar to indiscriminate convergence of cells) all result in an increase in neural sensitivity to modulation depth for both temporal and rate codes. For the across-cell method, pooling of a few dozen cells can result in detection thresholds that approximate those of the behaving animal. With synchrony measures, indiscriminate pooling results in sensitive detection of modulation frequencies between 20 and 60 Hz, suggesting that differences in AM response phase are minor in A1. phase locking synchrony neuronal pooling Copyright © 2012 the American Physiological Society « Previous | Next Article » Table of Contents This Article Published online before print March 14, 2012 , doi: 10.​1152/​jn.​00812.​2011 AJP - JN Physiol June 15, 2012 vol. 107 no. 12 3325-3341 » Abstract Free Full Text Full Text (PDF) All Versions of this Article: jn.00812.2011v1 107/12/3325 most recent Classifications Article Services Email this article to a friend Alert me when this article is cited Alert me if a correction is posted Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Download to citation manager Citing Articles Load citing article information Citing articles via Web of Science Google Scholar Articles by Johnson, J. S. Articles by Sutter, M. L. PubMed PubMed citation Articles by Johnson, J. S. Articles by Sutter, M. L. Related Content Load related web page information Current Content June 15, 2012 Alert me to new issues of AJP - JN Physiol About the Journal Calls for Papers Information for Authors Submit a Manuscript Ethical Policies AuthorChoice PubMed Central Policy Reprints and Permissions Advertising Press Copyright © 2012 the American Physiological Society Print ISSN: 0022-3077 Online ISSN: 1522-1598