scholarly journals Hypothesized mechanisms through which acute exercise influences episodic memory

2018 ◽  
Vol 105 (4) ◽  
pp. 285-297 ◽  
Author(s):  
PD Loprinzi ◽  
P Ponce ◽  
E Frith

Emerging research demonstrates that exercise is favorably associated with several cognitive outcomes, including episodic memory function. The majority of the mechanistic work describing the underlying mechanisms of this effect has focused on chronic exercise engagement. Such mechanisms include, e.g., chronic exercise-induced neurogenesis, gliogenesis, angiogenesis, cerebral circulation, and growth factor production. Less research has examined the mechanisms through which acute (vs. chronic) exercise subserves episodic memory function. The purpose of this review is to discuss these potential underlying mechanisms, which include, e.g., acute exercise-induced (via several pathways, such as vagus nerve and muscle spindle stimulation) alterations in neurotransmitters, synaptic tagging/capturing, associativity, and psychological attention.

2019 ◽  
Vol 9 (2) ◽  
pp. 99-104 ◽  
Author(s):  
Lauren Johnson ◽  
Paul D. Loprinzi

Background: The objective of this study was to evaluate potential sex-specific differences on episodic memory function and determine whether sex moderates the effects of acute exercise on episodic memory.Methods: A randomized controlled intervention was employed. This experiment was conducted among young University students (mean age = 21 years). Both males (n=20) and females (n=20)completed two counterbalanced laboratory visits, with one visit involving a 15-minute bout of moderate-intensity exercise prior to the memory task. The control visit engaged in a time matched seated task. Memory function (including short-term memory, learning, and long-term memory) was assessed from the RAVLT (Rey Auditory Verbal Learning Test).Results: We observed a significant main effect for time (P<0.001, ƞ2p= 0.77) and a marginally significant main effect for sex (P=0.06, ƞ2p= 0.09), but no time by sex by condition interaction(P=0.91, ƞ2p= 0.01). We also observed some suggestive evidence of a more beneficial effect of acute exercise on memory for females. Conclusion: In conclusion, females outperformed males in verbal memory function. Additional research is needed to further evaluate whether sex moderates the effects of acute exercise on memory function.


1999 ◽  
Vol 277 (6) ◽  
pp. H2247-H2252 ◽  
Author(s):  
R. S. Richardson ◽  
H. Wagner ◽  
S. R. D. Mudaliar ◽  
R. Henry ◽  
E. A. Noyszewski ◽  
...  

Vascular endothelial growth factor (VEGF) is involved in extracellular matrix changes and endothelial cell proliferation, both of which are precursors to new capillary growth. Angiogenesis is a vital adaptation to exercise training, and the exercise-induced reduction in intracellular[Formula: see text] has been proposed as a stimulus for this process. Thus we studied muscle cell[Formula: see text] [myoglobin[Formula: see text]([Formula: see text])] during exercise in normoxia and in hypoxia (12% O2) and studied the mRNA levels of VEGF in six untrained subjects after a single bout of exercise by quantitative Northern analysis. Single-leg knee extension provided the acute exercise stimulus: a maximal test followed by 30 min at 50% of the peak work rate achieved in this graded test. Because peak work rate was not affected by hypoxia, the absolute and relative work rates were identical in hypoxia and normoxia. Three pericutaneous needle biopsies were collected from the vastus lateralis muscle, one at rest and then the others at 1 h after exercise in normoxia or hypoxia. At rest (control), VEGF mRNA levels were very low (0.38 ± 0.04 VEGF/18S). After exercise in normoxia or hypoxia, VEGF mRNA levels were much greater (16.9 ± 6.7 or 7.1 ± 1.8 VEGF/18S, respectively). In contrast, there was no measurable basic fibroblast growth factor mRNA response to exercise at this 1-h postexercise time point. Magnetic resonance spectroscopy of myoglobin confirmed a reduction in[Formula: see text] in hypoxia (3.8 ± 0.3 mmHg) compared with normoxia (7.2 ± 0.6 mmHg) but failed to reveal a relationship between [Formula: see text] during exercise and VEGF expression. This VEGF mRNA increase in response to acute exercise supports the concept that VEGF is involved in exercise-induced skeletal muscle angiogenesis but questions the importance of a reduced cellular [Formula: see text]as a stimulus for this response.


2004 ◽  
Vol 68 (4) ◽  
pp. 304-307 ◽  
Author(s):  
Satoshi Yasuda ◽  
Yoichi Goto ◽  
Hiroshi Takaki ◽  
Yasuhide Asaumi ◽  
Takeshi Baba ◽  
...  

2000 ◽  
Vol 88 (4) ◽  
pp. 1192-1198 ◽  
Author(s):  
Timothy P. Gavin ◽  
David A. Spector ◽  
Harrieth Wagner ◽  
Ellen C. Breen ◽  
Peter D. Wagner

Vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and transforming growth factor-β1 (TGF-β1) mRNA increase in rat skeletal muscle in response to a single acute exercise bout. Nitric oxide (NO) is released locally by muscle vascular endothelium and muscle fibers during exercise, contributes to the blood flow response to exercise, and regulates mitochondrial respiration. We hypothesized that a reduction in NO production, via NO synthase inhibition, would demonstrate a link between NO and the VEGF, bFGF, and TGF-β1 gene responses to exercise. To investigate this hypothesis, 9-wk-old female Wistar rats were divided into eight treatment groups ( n = 6 each): 1) saline + rest, 2) saline + exercise, 3) 30 mg/kg N ω-nitro-l-arginine methyl ester (l-NAME, a known NOS inhibitor) + rest, 4) 30 mg/kgl-NAME + exercise, 5) 300 mg/kg l-NAME + rest, 6) 300 mg/kg l-NAME + exercise, 7) 300 mg/kg N ω-nitro-d-arginine methyl ester (d-NAME, inactive enantiomer of l-NAME) + rest, and 8) 300 mg/kg d-NAME + exercise. Exercise consisted of 1 h of running at 20 m/min on a 10° incline. VEGF, TGF-β1, and bFGF mRNA from left gastrocnemius were analyzed by quantitative Northern blot. Submaximal exercise for 1 h increased VEGF mRNA 4.2-fold and TGF-β1 mRNA 1.5-fold in untreated rats but did not increase bFGF mRNA. The exercise-induced increase in VEGF mRNA was attenuated ∼50% by 30 and 300 mg/kgl-NAME; the TGF-β1 mRNA increase was unaffected by 300 mg/kg l-NAME. In addition, 300 mg/kgd-NAME had no effect on the exercise-induced increase in VEGF mRNA. Administration of 300 mg/kg l-NAME had no effect on bFGF mRNA. These findings suggest that NO is important in the regulation of the VEGF gene response to exercise through increases in VEGF transcription or by increases in the VEGF mRNA half-life.


Author(s):  
Logan K. Townsend ◽  
Kyle D. Medak ◽  
Alyssa J. Weber ◽  
Hana Dibe ◽  
Hesham Shamshoum ◽  
...  

Growth differentiating factor-15 (GDF15) is expressed, and secreted, from a wide range of tissues and serves as a marker of cellular stress. A key transcriptional regulator of this hormone is the endoplasmic reticulum stress protein, CHOP (C/EBP Homologous Protein). Exercise increases GDF15 levels but the underlying mechanisms of this are not known. To test whether CHOP regulates GDF15 during exercise we used various models of altered ER stress. We examined the effects of acute exercise on circulating GDF15 and GDF15 mRNA expression in liver, triceps skeletal muscle, and epididymal white adipose tissue and examined the GDF15 response to acute exercise in lean and high-fat diet-induced obese mice, sedentary and exercise trained mice, and CHOP deficient mice. We found that obesity augments exercise-induced circulating GDF15 although ER stress markers were similar in lean and obese mice. Exercise-induced GDF15 was increased in trained and sedentary mice that ran at the same relative exercise intensity, despite trained mice being protected against increased markers of ER stress. Finally, exercise-induced increases in GDF15 at the tissue and whole-body level were intact in CHOP deficient mice. Together, these results provide evidence that exercise-induced GDF15 expression and secretion occurs independent of ER stress/CHOP.


2017 ◽  
Vol 123 (2) ◽  
pp. 434-441 ◽  
Author(s):  
Daniel D. Shill ◽  
Kristine R. Polley ◽  
T. Bradley Willingham ◽  
Jarrod A. Call ◽  
Jonathan R. Murrow ◽  
...  

Acute exercise-induced inflammation is implicated in mediating the beneficial adaptations to regular exercise. Evidence suggests that reduced oxygen and/or blood flow to contracting muscle alters cytokine appearance. However, the acute inflammatory responses to hypoxic/ischemic exercise have been documented with inconsistent results and may not accurately reflect the ischemia produced during exercise in patients with ischemic cardiovascular diseases. Therefore, we determined the extent to which local inflammation is involved in the response to ischemic exercise. Fourteen healthy males performed unilateral isometric forearm contractions for 30 min with and without experimental ischemia. Blood was drawn at baseline, 5 and 10 min into exercise, at the end of exercise, and 30, 60, and 120 min after exercise. Oxygen saturation levels, as measured by near-infrared spectroscopy, were reduced by 10% and 41% during nonischemic and ischemic exercise, respectively. Nonischemic exercise did not affect cytokine values. Ischemia enhanced concentrations of basic fibroblast growth factor, interleukin (IL)-6, IL-10, tumor necrosis factor-alpha, and vascular endothelial growth factor during exercise, but IL-8 was not influenced by ischemic exercise. In conclusion, the present study demonstrates that ischemic, small-muscle endurance exercise elicits local inflammatory cytokine production compared with nonischemic exercise. NEW & NOTEWORTHY We demonstrate that ischemic, small-muscle endurance exercise elicits local inflammatory cytokine production compared with nonischemic exercise. The present study advances our knowledge of the inflammatory response to exercise in a partial ischemic state, which may be relevant for understanding the therapeutic effects of exercise training for people with ischemic cardiovascular disease-associated comorbidities.


2019 ◽  
Vol 9 (4) ◽  
pp. 87 ◽  
Author(s):  
Paul Loprinzi ◽  
Jeremiah Blough ◽  
Lindsay Crawford ◽  
Seungho Ryu ◽  
Liye Zou ◽  
...  

Background: Accumulating research demonstrates that the timing of exercise plays an important role in influencing episodic memory. However, we have a limited understanding as to the factors that moderate this temporal effect. Thus, the purpose of this systematic review with meta-analysis was to evaluate the effects of study characteristics (e.g., exercise modality, intensity and duration of acute exercise) and participant attributes (e.g., age, sex) across each of the temporal periods of acute exercise on episodic memory (i.e., acute exercise occurring before memory encoding, and during memory encoding, early consolidation, and late consolidation). Methods: The following databases were used for our computerized searches: Embase/PubMed, Web of Science, Google Scholar, Sports Discus and PsychInfo. Studies were included if they: (1) Employed an experimental design with a comparison to a control group/visit, (2) included human participants, (3) evaluated exercise as the independent variable, (4) employed an acute bout of exercise (defined as a single bout of exercise), (5) evaluated episodic memory as the outcome variable (defined as the retrospective recall of information either in a spatial or temporal manner), and (6) provided sufficient data (e.g., mean, SD, and sample size) for a pooled effect size estimate. Results: In total, 25 articles met our inclusionary criteria and were meta-analyzed. Acute exercise occurring before memory encoding (d = 0.11, 95% CI: −0.01, 0.23, p = 0.08), during early memory consolidation (d = 0.47, 95% CI: 0.28, 0.67; p < 0.001) and during late memory consolidation (d = 1.05, 95% CI: 0.32, 1.78; p = 0.005) enhanced episodic memory function. Conversely, acute exercise occurring during memory encoding had a negative effect on episodic memory (d = −0.12, 95% CI: −0.22, −0.02; p = 0.02). Various study designs and participant characteristics moderated the temporal effects of acute exercise on episodic memory function. For example, vigorous-intensity acute exercise, and acute exercise among young adults, had greater effects when the acute bout of exercise occurred before memory encoding or during the early memory consolidation period. Conclusions: The timing of acute exercise plays an important role in the exercise-memory interaction. Various exercise- and participant-related characteristics moderate this temporal relationship.


2021 ◽  
pp. 174702182199457
Author(s):  
Paul D Loprinzi ◽  
Jeremy P Loenneke ◽  
Benjamin C Storm

Accumulating research provides suggestive evidence that acute aerobic exercise may, potentially, enhance episodic memory function post-exercise. Limited research has evaluated whether acute resistance exercise may also enhance episodic memory post-exercise. Furthermore, whether these two exercise modalities have a differential effect on post-exercise episodic memory is relatively unknown. To address these research questions, three experimental studies were conducted ( N = 104) among young adults (18–25 years). The experiments implemented acute bouts of aerobic or resistance exercise for 15 min. Episodic memory was comprehensively evaluated post-exercise with a list-learning paradigm and a computerised assessment of what-where-when aspects of episodic memory. Various manipulations (e.g., between vs. within-group) of the study design were implemented across the experiments. Across these three experiments, we failed to find consistent evidence of either type of acute exercise affecting episodic memory performance post-exercise.


2018 ◽  
Vol 122 (5) ◽  
pp. 1744-1754 ◽  
Author(s):  
James T. Haynes ◽  
Emily Frith ◽  
Eveleen Sng ◽  
Paul D. Loprinzi

Our previous work employing a between-subject randomized controlled trial design suggests that exercising prior to memory encoding is more advantageous in enhancing retrospective episodic memory function when compared to exercise occurring during or after memory encoding. The present experiment evaluates this potential temporal effect of acute exercise on memory function while employing a within-subject, counterbalanced design. In a counterbalanced order (via Latin squares), 24 participants completed four visits including (1) exercising (moderate-intensity walking) prior to memory encoding, (2) exercising during memory encoding, (3) exercising after memory encoding, and (4) a control visit (no exercise). Retrospective memory function (short term and long term; 24-hour follow-up) was assessed from a multitrial word list. Prospective memory was assessed from a time-based task. Compared to all other visits, short-term memory was greater in the visit that involved exercising prior to memory encoding (F = 3.76; P = .01; η2 = .79). Similar results occurred for long-term memory, with no significant effects for prospective memory performance. We provide robust evidence demonstrating that acute moderate-intensity exercise prior to memory encoding is optimal in enhancing short-term and long-term memory function when compared to no exercise as well as exercising during and after memory encoding.


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