Evidence map›Paper›PMID 42670046›Full record

ArticleBrain and behavior2026

The Impact of Overtraining on Anxiety-Like Behavior and Tight Junction Proteins of the Blood-Brain Barrier in Mice.

Eunseon Hwang, Minyoung Shin, Taeeon Park, Jeremy J Kim, Dongheon Yi, Jeayeon Park, Hyo Youl Moon

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Article in Brain and behavior, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

7 authors.

Eunseon HwangDepartment of Physical Education, Seoul National University, Seoul, South Korea.
Minyoung ShinDepartment of Physical Education, Seoul National University, Seoul, South Korea.
Taeeon ParkDepartment of Physical Education, Seoul National University, Seoul, South Korea.
Jeremy J KimDepartment of Physical Education, Seoul National University, Seoul, South Korea.
Dongheon YiDepartment of Physical Education, Seoul National University, Seoul, South Korea.
Jeayeon ParkDepartment of Physical Education, Seoul National University, Seoul, South Korea.
Hyo Youl MoonDepartment of Physical Education, Seoul National University, Seoul, South Korea.

Funding

National Research Foundation of Korea (NRF) NRF-2026S1A5A2A01005211National Research Foundation of Korea (NRF) RS-2022-NR070859National Research Foundation of Korea (NRF) RS-2025-16066994
6 · The paper itself

Abstract

purposeOvertraining Syndrome (OTS) is a chronic maladaptive condition characterized by persistent performance decline due to excessive training and inadequate recovery. OTS is associated with mood disturbances, but the underlying neurobiological mechanisms remain unclear. This study investigated whether a 6-week overtraining (OT) protocol induces anxiety-like behavior and changes in hippocampal BBB-related tight junction proteins in mice.

methodsEight-week-old male C57BL/6J mice were assigned to sedentary (SED, n = 5), moderate exercise (ME, n = 5), or overtraining (OT; downhill treadmill running, initially n = 10) groups and completed a 6-week training protocol. The final OT sample size was n = 4 after 6 of the 10 mice were excluded due to tail or hindlimb injuries. Endurance capacity was assessed using an incremental loading test (ILT). Anxiety-like behaviors were evaluated using the nest building test (NBT), open-field test (OFT), and elevated plus maze (EPM). Hippocampal tight junction (TJ) proteins zonula occludens-1 (ZO-1), occludin, claudin-5, as well as tumor necrosis factor-alpha (TNF-α) were quantified by Western blot analysis.

resultsAfter 6 weeks, endurance performance in the OT group significantly decreased from baseline (p < 0.01) and was lower than that of the ME group at Week 6 (p < 0.0001). In the quadriceps, TNF-α protein levels were significantly elevated in the OT group compared with both the SED (p < 0.05) and ME groups (p < 0.01). In the OFT, OT mice exhibited fewer center entries and reduced time spent in the center zone versus the SED and ME groups (p < 0.05), indicating increased anxiety related behavioral change. In the hippocampus, zonula occludens-1 (ZO-1) levels were reduced and TNF-α levels were elevated in OT compared with SED (p < 0.01 and p < 0.05, respectively), whereas claudin-5 levels were higher in ME than SED (p < 0.05).

conclusionOT was associated with anxiety-like behavioral alterations and changes in hippocampal BBB-related tight junction proteins. Reduced expression of TJ proteins and increased neuroinflammation may contribute to affective symptoms observed in OTS. However, given the small final sample size in the OT group, these findings should be interpreted with caution.

Indexed as

AnxietyBehavior, AnimalBlood-Brain BarrierOvertraining SyndromePhysical Conditioning, AnimalTight Junction ProteinsAnimalsHippocampusMaleMiceMice, Inbred C57BLTight Junction Proteinsanxiety‐like behaviorblood–brain barrierneuroinflammationOvertraining Syndrome

Identifiers

PMID42670046
PMCPMC13527226

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.