{"doi":"10.1016/j.bj.2019.07.007","title":"Novel human models for elucidating mechanisms of rate-sensitive H-reflex depression","abstract":"BACKGROUND: This study used novel human neurophysiologic models to investigate whether the mechanism of rate-sensitive H-reflex depression lies in the pre-synaptic or post-synaptic locus in humans. We hypothesized that pre-synaptic inhibition would suppress Ia afferents and H-reflexes without suppressing alpha motor neurons or motor evoked potentials (MEPs). In contrast, post-synaptic inhibition would suppress alpha motor neurons, thereby reducing H-reflexes and MEPs. METHODS: We recruited 23 healthy adults with typical rate-sensitive H-reflex depression, 2 participants with acute sensory-impaired spinal cord injury (SCI) (to rule out influence of sensory stimulation on supra-spinal excitability), and an atypical cohort of 5 healthy adults without rate-sensitive depression. After a single electrical stimulation to the tibial nerve, we administered either a testing H-reflex or a testing MEP at 50-5000 ms intervals. RESULTS: Testing MEPs were not diminished in healthy subjects with or without typical rate-sensitive H-reflex depression, or in subjects with sensory-impaired SCI. MEP responses were similar in healthy subjects with versus without rate-sensitive H-reflex depression. CONCLUSIONS: Results from these novel in vivo human models support a pre-synaptic locus of rate-sensitive H-reflex depression for the first time in humans. Spinal reflex excitability can be modulated separately from descending corticospinal influence. Each represents a potential target for neuromodulatory intervention.","journal":"Biomedical Journal","year":2020,"id":88015,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":10,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.962,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":446900,"name":"Yu‐Ching Liu","orcid":"0000-0001-7747-4376","position":1,"is_corresponding":false},{"id":446901,"name":"Miao‐Ju Hsu","orcid":"0000-0002-4944-9920","position":2,"is_corresponding":false},{"id":448064,"name":"Chia-Ying Fang","orcid":null,"position":3,"is_corresponding":false},{"id":446902,"name":"May‐Kuen Wong","orcid":"0000-0003-3586-1292","position":4,"is_corresponding":false},{"id":446903,"name":"Stacey L. DeJong","orcid":"0000-0001-6929-5693","position":5,"is_corresponding":false},{"id":446904,"name":"Richard K. Shields","orcid":"0000-0002-5838-9317","position":6,"is_corresponding":false},{"id":254300,"name":"Ya‐Ju Chang","orcid":"0000-0002-9102-4352","position":0,"is_corresponding":true}],"reference_count":47,"raw_metadata":null,"created_at":"2026-07-18T22:00:56.736935Z","pmid":"32200955","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}