title: Ambient temperature influences the neural benefits of exercise.
abstract: Many of the neural benefits of exercise require weeks to manifest. It would be useful to accelerate onset of exercise-driven plastic changes, such as increased hippocampal neurogenesis. Exercise represents a significant challenge to the brain because it produces heat, but brain temperature does not rise during exercise in the cold. This study tested the hypothesis that exercise in cold ambient temperature would stimulate hippocampal neurogenesis more than exercise in room or hot conditions. Adult female rats had exercise access 2h per day for 5 days at either room (20 °C), cold (4.5 °C) or hot (37.5 °C) temperature. To label dividing hippocampal precursor cells, animals received daily injections of BrdU. Brains were immunohistochemically processed for dividing cells (Ki67+), surviving cells (BrdU+) and new neurons (doublecortin, DCX) in the hippocampal dentate gyrus. Animals exercising at room temperature ran significantly farther than animals exercising in cold or hot conditions (room 1490 ± 400 m; cold 440 ± 102 m; hot 291 ± 56 m). We therefore analyzed the number of Ki67+, BrdU+ and DCX+ cells normalized for shortest distance run. Contrary to our hypothesis, exercise in either cold or hot conditions generated significantly more Ki67+, BrdU+ and DCX+ cells compared to exercise at room temperature. Thus, a limited amount of running in either cold or hot ambient conditions generates more new cells than a much greater distance run at room temperature. Taken together, our results suggest a simple means by which to augment exercise effects, yet minimize exercise time.
authors.affiliation: Department of Psychology, University of Houston, Houston, TX 77204-5022, United States.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Maynard
authors.affiliation: Department of Psychology, University of Houston, Houston, TX 77204-5022, United States.
authors.forename: Chasity
authors.initials: C
authors.lastname: Chung
authors.affiliation: Department of Psychology, University of Houston, Houston, TX 77204-5022, United States.
authors.forename: Ashley
authors.initials: A
authors.lastname: Comer
authors.affiliation: Department of Psychology, University of Houston, Houston, TX 77204-5022, United States.
authors.forename: Katharine
authors.initials: K
authors.lastname: Nelson
authors.affiliation: Department of Psychology, University of Houston, Houston, TX 77204-5022, United States.
authors.forename: Jamie
authors.initials: J
authors.lastname: Tran
authors.affiliation: Department of Psychology, University of Houston, Houston, TX 77204-5022, United States.
authors.forename: Nadja
authors.initials: N
authors.lastname: Werries
authors.affiliation: Department of Psychology, University of Houston, Houston, TX 77204-5022, United States.
authors.forename: Emily A
authors.initials: EA
authors.lastname: Barton
authors.affiliation: Department of Psychology, Seattle University, Seattle, WA 98122, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Spinetta
authors.affiliation: Department of Psychology, University of Houston, Houston, TX 77204-5022, United States; Department of Biology & Biochemistry, University of Houston, Houston, TX 77204-5022, United States. Electronic address: jlleasure@uh.edu.
authors.forename: J Leigh
authors.initials: JL
authors.lastname: Leasure
mesh_terms: D000305:Adrenal Cortex Hormones / Q000032:analysis; D000818:Animals; D000963:Antimetabolites / Q000008:administration & dosage; D001973:Bromodeoxyuridine / Q000008:administration & dosage; D018891:Dentate Gyrus / Q000187:drug effects; D000089662:Doublecortin Protein; D005243:Feces / Q000737:chemistry; D005260:Female; D006624:Hippocampus / Q000187:drug effects; D055495:Neurogenesis / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D020318:Rats, Long-Evans; D013696:Temperature
chemical_list: D000305:Adrenal Cortex Hormones; D000963:Antimetabolites; C000714848:Dcx protein, rat; D000089662:Doublecortin Protein; D001973:Bromodeoxyuridine
keywords: Brain injury; Exercise; Hippocampus; Neurogenesis; Temperature