Hypothesized mechanisms through which acute exercise influences episodic memory

Abstract

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.

Effects of Intensity-Specific Acute Exercise on Paired-Associative Memory and Memory Interference

“…To address these gaps in the literature, our study implemented a within-subject design to examine the potential intensity-specific effects of acute exercise on paired-associative memory and memory interference. Previous literature demonstrates that acute exercise can enhance memory function [6,10,15,20,21,38,69]. Our findings align with these previous experiments.…”

“…Notably, however, as we have demonstrated in a recent systematic review [20], there may be an intensity-specific effect of acute exercise on enhancing episodic memory, with higher-intensity exercise potentially being optimal. Further, as we thoroughly addressed elsewhere [20,21], higher-intensity exercise may enhance long-term potentiation (LTP) to a greater extent than lower-intensity exercise, which may explain these potential intensity-specific effects, as LTP is considered an underlying mechanistic correlate of episodic memory [22]. However, as we discussed recently [20], higher-intensity acute exercise may impair working memory by increasing the levels of dopamine and norepinephrine in the prefrontal cortex and, ultimately, dampen neural activity via cAMP opening of nearby K+ channels [20,23].…”

Experimental Manipulation of Psychological Control Scenarios: Implications for Exercise and Memory Research

“…As stated in the methods section, we intentionally did not employ a cognitive disengagement control because of the time period (i.e., 20 min), but for future studies that are evaluating the effects of very short bouts of exercise (e.g., 5 min of walking [45] or high-intensity interval training), this cognitive disengagement control may be more appropriate to evaluate. As we have thoroughly discussed elsewhere [46,47], one of the postulated mechanisms through which exercise may influence memory function is via exercise-induced increases in long-term potentiation, or sustained neuronal excitability. Hippocampal long-term potentiation from acute exercise is thought to occur through several pathways, including activation of the muscle stretch receptors and the vagus nerve.…”

Does Engaging in Acute Exercise Prior to Memory Encoding and During Memory Consolidation have an Additive Effect on Long-Term Memory Function?

“…Acute exercise during both of these time periods may activate unique mechanisms to enhance long-term memory. For example, as thoroughly detailed elsewhere [18,21], acute exercise prior to memory encoding may induce neuronal excitability in key memory structures (e.g., hippocampus), ultimately facilitating long-term potentiation [15], or enhanced communication across neurons. Further, acute exercise prior to memory encoding may increase psychological arousal, which may help facilitate memory encoding via enhanced attention on the task [21].…”

“…For example, as thoroughly detailed elsewhere [18,21], acute exercise prior to memory encoding may induce neuronal excitability in key memory structures (e.g., hippocampus), ultimately facilitating long-term potentiation [15], or enhanced communication across neurons. Further, acute exercise prior to memory encoding may increase psychological arousal, which may help facilitate memory encoding via enhanced attention on the task [21]. Acute exercise during the early consolidation period (i.e., after memory encoding), however, may augment neurotrophic factors (e.g., brain-derived neurotropic factor [14,19], insulin-like growth factor-1 [16]), which in turn may help to stabilize the memory trace, ultimately helping facilitate the consolidation of the memory.…”