Developmental decrease in size of peripheral receptive fields of single chorda tympani nerve fibers and relation to increasing NaCl taste sensitivity.

T Nagai; C M Mistretta; R M Bradley

Home/Archive/PubMed

PubMed · 3339419

Developmental decrease in size of peripheral receptive fields of single chorda tympani nerve fibers and relation to increasing NaCl taste sensitivity.

T Nagai·C M Mistretta·R M Bradley

View original source ↗Export metadata ↓

Abstract

During development in rats, sheep, and humans, the taste system acquires increasing responsiveness to NaCl, compared with a variety of other salts and chemicals. To better understand the neural basis of changes in salt taste responses, we studied receptive field size and response properties of single chorda tympani nerve fibers in fetal, perinatal, and postnatal sheep. Individual fungiform papillae were stimulated electrically with 5 microA anodal current to determine the location and number of papillae in receptive fields. Response characteristics of NH4Cl, NaCl, and KCl were determined for the entire field. Receptive fields were dissected for later histological reconstruction and taste bud identification. Median receptive field size decreased during development. Field sizes in lambs were smaller than those in younger animals. This decrease was accompanied by an increase in the NaCl/NH4Cl response ratio of single fibers and an increase in the proportion of fibers and associated fields that responded with higher frequency to NaCl, compared with NH4Cl. In addition, for fibers across all age groups, receptive field size correlated negatively with the NaCl/NH4Cl response ratio; that is, fields most responsive to NaCl had fewer papillae than those most responsive to NH4Cl. For all fibers, receptive field size correlated with response frequencies to NH4Cl and KCl but not NaCl. For NaCl-best fibers, receptive field size correlated with the response frequencies to all 3 salts. There was no relation between number of taste buds in a single fungiform papilla and the response frequency elicited during electrical stimulation of the papilla.(ABSTRACT TRUNCATED AT 250 WORDS)

Explore related subjects

Aging Animals Animals, Newborn Chorda Tympani Nerve Electric Stimulation Female Fetus Nerve Fibers Pregnancy Sheep Sodium Chloride Taste Journal Article Research Support, U.S. Gov't, Non-P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

T Nagai, C M Mistretta, R M Bradley. 1988. Developmental decrease in size of peripheral receptive fields of single chorda tympani nerve fibers and relation to increasing NaCl taste sensitivity.. https://pubmed.ncbi.nlm.nih.gov/3339419/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2026

An open benchmark and language models for AI in aging biology.

Over the past two decades, human aging has been characterized across DNA methylation, transcriptomic, proteomic, and clinical modalities, yet no benchmark evaluates whether AI systems can interpret these heterogeneous data types in the context of aging biology. We introduce LongevityBench, an open suite of 17 tasks spanning five biodata domains, and use it to assess 18 frontier AI systems from six developer teams. Despite recent advances in AI, no single model dominates all tasks, with omics-based age prediction being the hardest task regardless of scale. To test whether these gaps can be closed without frontier-scale resources, we fine-tuned a family of five multitask Longevity-LLMs on domain-specific aging data. The compact (0.6B-9B parameters) Longevity-LLMs matched or exceeded far larger frontier systems on LongevityBench, showing that general-purpose language models can be adapted to structured-omics tasks. We publicly release the benchmark, models, and Longevity Claw, an agentic research interface for aging researchers.

Aging↗

PubMed2026

Association between sirtuin 1 and markers of oxidative stress in master athletes.

BACKGROUND: Lifelong training in master athletes confers protective effects, promoting higher sirtuin levels and enhanced antioxidant capacity. Although Sirtuin 1 (SIRT1) is well studied, no previous study has examined the relationship between circulating SIRT1 levels and antioxidant defense variables in master athletes. PURPOSE: To compare and analyze the relationships between circulating levels of SIRT1 and variables related to antioxidant defense in master athletes (MA) and untrained middle-aged individuals (UMA). METHODS: Male MA (n = 42; 51.62 ± 7.33 years; ≥10 years of training and competition in running) and UMA (n = 15; 47.73 ± 8.52 years) were evaluated. Venous blood samples were collected for biochemical analyses of SIRT1, antioxidant enzymes, TBARS and F2-isoprostanes, 8-OHdG, and redox balance indexes. RESULTS: MA showed higher levels of SIRT1 (18.22 ± 4.53 vs. 6.08 ± 2.11 ng/mL; p < 0.0001), as well as of SOD, CAT, and GSH (p < 0.001), indicating a more favorable antioxidant profile. After adjustment for body fat percentage, differences in SOD, CAT, GSH and TBARS, remained significant. SIRT1 was positively correlated with SOD (r = 0.279; p = 0.031), CAT (r = 0.485; p < 0.001), GSH (r = 0.476; p < 0.001) and CAT/8-OHdG (r = 0.430; p = 0.032), and negatively correlated with TBARS (r = - 0.518; p < 0.001). CONCLUSION: Master athletes exhibited higher circulating SIRT1 concentrations and a more favorable systemic redox profile than untrained individuals, with SIRT1 being associated with markers of antioxidant defense, lipid peroxidation, and redox balance.

Aging↗

PubMed2026

Decoding SUMOylation as a metabolic stress sensor in aging and age-related disorders: Mechanisms, tissue specificity and therapeutic potential.

SUMOylation is a reversible post-translational modification increasingly recognized for its role in coordinating cellular responses to metabolic stress during aging. Emerging evidence indicates that it functions beyond a conventional modification, representing an adaptive stress‑responsive regulatory network that integrates metabolic, oxidative, inflammatory, and proteotoxic signals. Rather than acting on isolated pathways, this network finely tunes mitochondrial function, proteostasis, genome maintenance, immune balance, and epigenetic regulation. Accumulating evidence indicates that SUMO-dependent regulation exhibits remarkable tissue specificity, supporting mitochondrial adaptation and contractile integrity in skeletal muscle, shaping lipid and glucose metabolism in the liver, modulating proteotoxic stress and neuronal resilience in the brain, and contributing to immune cell differentiation and chronic low-grade inflammation during aging. In this review, we summarize current mechanistic insights into SUMO signaling across aging-relevant tissues, with particular emphasis on its functional interplay with other post-translational modifications, including ubiquitination and acetylation. We discuss how SUMOylation operates as a shared regulatory layer while enabling context-dependent outcomes that underlie diverse aging phenotypes and age-related disorders. Finally, we evaluate emerging translational approaches-ranging from pharmacological modulation of SUMO enzymes to lifestyle interventions such as caloric restriction and exercise-that highlight both the opportunities and challenges of targeting SUMO-regulated stress responses in aging. Together, this synthesis provides a framework for understanding how SUMOylation links metabolic stress to tissue-specific aging trajectories and therapeutic potential.

Aging↗