title: Different types of exercise induce differential effects on neuronal adaptations and memory performance.
abstract: Different exercise paradigms show differential effects on various forms of memory. We hypothesize that the differential effects of exercises on memory performance are caused by different neuroplasticity changes in relevant brain regions in response to different exercise trainings. We examined the effects of treadmill running (TR) and wheel running (WR) on the Pavlovian fear conditioning task that assesses learning and memory performance associated with the amygdala (cued conditioning) and both the amygdala and hippocampus (contextual conditioning). The skeletal muscle citrate synthase activity, an indicator of aerobic capacity, was elevated in rats received 4 w of TR, but not WR. While both TR and WR elevated the contextual conditional response, only TR facilitated the cued conditional response. Using a single-neuron labeling technique, we found that while both TR and MR enlarged the dendritic field and increased the spine density in hippocampal CA3 neurons, only TR showed these effects in basolateral amygdalar neurons. Moreover, both types of exercise upregulated synaptic proteins (i.e., TrkB and SNAP-25) in the hippocampus; however only TR showed similar effects in the amygdala. Injection of K252a, a TrkB kinase inhibitor, in the dorsal hippocampus or basolateral amygdala abolished the exercise-facilitated contextual or cued fear learning and memory performance, respectively, regardless of the types of exercise. In summary, our results supported that different types of exercise affect the performance of learning and memory via BDNF-TrkB signaling and neuroplasticity in specific brain regions. The brain region-specific neuronal adaptations are possibly induced by various levels of intensity/stress elicited by different types of exercise.
authors.affiliation: Department of Physiology, National Cheng Kung University, Tainan, Taiwan.
authors.forename: Tzu-Wei
authors.initials: TW
authors.lastname: Lin
authors.forename: Shean-Jen
authors.initials: SJ
authors.lastname: Chen
authors.forename: Tung-Yi
authors.initials: TY
authors.lastname: Huang
authors.forename: Chia-Yuan
authors.initials: CY
authors.lastname: Chang
authors.forename: Jih-Ing
authors.initials: JI
authors.lastname: Chuang
authors.forename: Fong-Sen
authors.initials: FS
authors.lastname: Wu
authors.forename: Yu-Min
authors.initials: YM
authors.lastname: Kuo
authors.forename: Chauying J
authors.initials: CJ
authors.lastname: Jen
mesh_terms: D000679:Amygdala / Q000502:physiology; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D003214:Conditioning, Classical / Q000502:physiology*; D003463:Cues; D049229:Dendritic Spines / Q000502:physiology*; D005239:Fear / Q000502:physiology; D006624:Hippocampus / Q000502:physiology; D008568:Memory / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000379:methods* / Q000502:physiology; D051381:Rats; D020813:Receptor, trkB / Q000378:metabolism; D050825:Synaptosomal-Associated Protein 25 / Q000378:metabolism; D050863:Synaptotagmin I / Q000378:metabolism
chemical_list: D019208:Brain-Derived Neurotrophic Factor; C494210:Snap25 protein, rat; D050825:Synaptosomal-Associated Protein 25; D050863:Synaptotagmin I; C494312:Syt1 protein, rat; D020813:Receptor, trkB