Responses to Binary Taste Mixtures in the Nucleus of the Solitary Tract: Neural Coding With Firing Rate

Chen, Jen-Yung; Lorenzo, Patricia M. Di

doi:10.1152/jn.01020.2007

Cited by 20 publications

(12 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1, 4, and 5), are not atypical for medullary neurons. Other studies of NTS units in mice and rats have shown latencies to response, and to maximal activation, to room temperature sucrose of near 1 s from stimulus onset (Chen and Di Lorenzo 2008;McCaughey 2007). Considering the present effects of cooling on latency, these lags would be expected to further increase with reduction in solution temperature.…”

Section: Considerations and Conclusionmentioning

confidence: 81%

Temperature systematically modifies neural activity for sweet taste

Wilson

Lemon

2014

Journal of Neurophysiology

View full text Add to dashboard Cite

Wilson DM, Lemon CH. Temperature systematically modifies neural activity for sweet taste. J Neurophysiol 112: 1667-1677, 2014. First published June 25, 2014 doi:10.1152 doi:10. /jn.00368.2014 can modify neural and behavioral responses to taste stimuli that elicit "sweetness," a perception linked to intake of calorie-laden foods. However, the role of temperature in the neural representation of sweet taste is poorly understood. Here we made electrophysiological recordings from gustatory neurons in the medulla of inbred mice to study how adjustments in taste solution temperature to cool (18°C), ambient (22°C), and warm (30°C and 37°C) values changed the magnitude and latency of gustatory activity to sucrose (0, 0.05, 0.1, 0.17, 0.31, and 0.56 M). Analysis of 22 sucrose-best neurons revealed that temperature markedly influenced responses to sucrose, which, across concentrations, were largest when solutions were warmed to 30°C. However, reducing solution temperature from warm to ambient to cool progressively steepened the slope of the sucrose concentrationresponse function computed across cells (P Ͻ 0.05), indicating that mean activity to sucrose increased more rapidly with concentration steps under cooling than with warming. Thus the slope of the sucrose concentration-response function shows an inverse relation with temperature. Temperature also influenced latency to the first spike of the sucrose response. Across neurons, latencies were shorter when sucrose solutions were warmed and longer, by hundreds of milliseconds, when solutions were cooled (P Ͻ 0.05), indicating that temperature is also a temporal parameter of sucrose activity. Our findings reveal that temperature systematically modifies the timing of gustatory activity to sucrose in the mammalian brain and how this activity changes with concentration. Results further highlight how oral somatosensory cues function as physiological modulators of gustatory processing. taste; sucrose; temperature; latency; coding THE STUDY OF NEURAL CODING involves, in part, relating features of sensory stimuli to neural activity. For taste, this pursuit has largely focused on two stimulus features: the perceptual quality of the taste chemical and its concentration while dissolved in solution. Taste quality is a descriptive characteristic of taste stimuli transmitted, in part, through substitution (cf. Stevens 1961) of responses by different neurons. For instance, exchanging a taste stimulus of one quality (e.g., "sweet") for another (e.g., "salty") can cause a substitutive change in the neurons that respond maximally to the stimulus, leading to an associated change in the evoked response pattern. Concentration, on the other hand, is a physical property of taste stimuli that guides the magnitude of gustatory responses.Temperature is an additional physical property of taste stimuli that can modulate gustatory processing. Temperature strongly influences neural and behavioral responses to sweet stimuli. Gustatory activity to sucrose in peripheral nerves carrying sensory input fro...

show abstract

Section: Considerations and Conclusionmentioning

confidence: 81%

Temperature systematically modifies neural activity for sweet taste

Wilson

Lemon

2014

Journal of Neurophysiology

View full text Add to dashboard Cite

show abstract

“…Spontaneous firing rate was 1.9 ± 0.3 spikes per sec (sps). These cells were a subset of a dataset whose detailed tuning characteristics are described in another paper (Chen and Di Lorenzo, 2008). Cells in the present paper were those that had a sufficient number of stimulus presentations of all 10 tastants for temporal coding analyses.…”

Section: Resultsmentioning

confidence: 99%

“…Presentation of mixtures of tastants of different qualities only adds to the confusion. We have shown that the across neuron pattern (ANP) of responses can go a long way toward resolving these ambiguities by providing a reasonable representation of the taste world (Chen and Di Lorenzo, 2008). Because the ANP is based on taste-evoked spike counts, it relies on the contribution of narrowly tuned cells; more broadly tuned cells in this model only add noise to the message.…”

Section: Introductionmentioning

confidence: 99%

Quality Time: Representation of a Multidimensional Sensory Domain through Temporal Coding

Lorenzo

Chen²,

Victor³

2009

J. Neurosci.

View full text Add to dashboard Cite

Receptive fields of sensory neurons in the brain are usually restricted to a portion of the entire stimulus domain. At all levels of the gustatory neuraxis, however, there are many cells that are broadly tuned, i.e., they respond well to each of the basic taste qualities (sweet, sour, salty, and bitter). Although it might seem that this broad tuning precludes a major role for these cells in representing taste space, here we show the opposite-namely, that the tastant-specific temporal aspects (firing rate envelope and spike timing) of their responses enable each cell to represent the entire stimulus domain. Specifically, we recorded the response patterns of cells in the nucleus of the solitary tract (NTS) to representatives of four basic taste qualities and their binary mixtures. We analyzed the temporal aspects of these responses, and used their similarities and differences to construct the taste space represented by each neuron. We found that for the more broadly tuned neurons in the NTS, the taste space is a systematic representation of the entire taste domain. That is, the taste space of these broadly tuned neurons is three dimensional, with basic taste qualities widely separated and binary mixtures placed close to their components. Further, the way that taste quality is represented by the firing rate envelope is consistent across the population of cells. Thus, the temporal characteristics of responses in the population of NTS neurons, especially those that are more broadly tuned, produce a comprehensive and logical representation of the taste world.

show abstract

“…5). Peripheral taste neurons, like rat brainstem taste neurons (Chen and Di Lorenzo, 2008), may naturally respond to multi-quality aversive stimuli. Rodents are assisted in discriminating among aversive chemosensory stimuli by sensations derived from trigeminal sensory nerves (Wang et al ., 1993; Pittman and Contreras, 1998); and, reflex salivation, elicited by sour tasting acids (Matsuo and Yamamoto, 1989; Bradley et al ., 2005), may contribute additional taste and texture cues to amplify or modify ongoing acid-elicited CT responses.…”

Section: Best-stimulus–behavior Consonancementioning

confidence: 99%

Cracking taste codes by tapping into sensory neuron impulse traffic

Frank

Lundy

Contreras

2008

Progress in Neurobiology

View full text Add to dashboard Cite

Insights into the biological basis for mammalian taste quality coding began with electrophysiological recordings from "taste" nerves and this technique continues to produce essential information today. Chorda tympani (geniculate ganglion) neurons, which are particularly involved in taste quality discrimination, are specialists or generalists. Specialists respond to stimuli characterized by a single taste quality as defined by behavioral cross-generalization in conditioned taste tests. Generalists respond to electrolytes that elicit multiple aversive qualities. Na + -salt (N) specialists in rodents and sweet-stimulus (S) specialists in multiple orders of mammals are well-characterized. Specialists are associated with species' nutritional needs and their activation is known to be malleable by internal physiological conditions and contaminated external caloric sources. S specialists, associated with the heterodimeric G-protein coupled receptor: T1R, and N specialists, associated with the epithelial sodium channel: ENaC, are consistent with labeled line coding from taste bud to afferent neuron. Yet, S-specialist neurons and behavior are less specific thanT1R2-3 in encompassing glutamate and E generalist neurons are much less specific than a candidate, PDK TRP channel, sour receptor in encompassing salts and bitter stimuli. Specialist labeled lines for nutrients and generalist patterns for aversive electrolytes may be transmitting taste information to the brain side by side. However, specific roles of generalists in taste quality coding may be resolved by selecting stimuli and stimulus levels found in natural situations. T2Rs, participating in reflexes via the glossopharynygeal nerve, became highly diversified in mammalian phylogenesis as they evolved to deal with dangerous substances within specific environmental niches. Establishing the information afferent neurons traffic to the brain about natural taste stimuli imbedded in dynamic complex mixtures will ultimately "crack taste codes."

show abstract

Responses to Binary Taste Mixtures in the Nucleus of the Solitary Tract: Neural Coding With Firing Rate

Cited by 20 publications

References 40 publications

Temperature systematically modifies neural activity for sweet taste

Temperature systematically modifies neural activity for sweet taste

Quality Time: Representation of a Multidimensional Sensory Domain through Temporal Coding

Cracking taste codes by tapping into sensory neuron impulse traffic

Contact Info

Product

Resources

About