Biomaterial Database

Voluntary running-wheel exercise decreases the threshold for rewarding intracranial self-stimulation. 2012

Michael J Morris, and Elisa S Na, and Alan Kim Johnson

Department of Psychology, The University of Iowa, Iowa City 52242-1407, USA.

Physical exercise has mood-enhancing and antidepressant properties although the mechanisms underlying these effects are not known. The present experiment investigated the effects of prolonged access to a running wheel on electrical self-stimulation of the lateral hypothalamus (LHSS), a measure of hedonic state, in rats. Rats with continuous voluntary access to a running wheel for either 2 or 5 weeks exhibited dramatic leftward shifts in the effective current 50 (ECu50; current value that supports half of maximum responding) of their LHSS current-response functions compared to their baselines, indicating a decrease in reward threshold, whereas control rats current-response functions after 2 or 5 weeks were not significantly different from baseline. An inverse correlation existed between the change in ECu50 from baseline and the amount an animal had run in the day prior to LHSS testing, indicating that animals that exhibited higher levels of running showed a more robust decrease in LHSS threshold. We conclude that long-term voluntary exercise increases sensitivity to rewarding stimuli, which may contribute to its antidepressant properties.

UI	MeSH Term	Description	Entries
D007026	Hypothalamic Area, Lateral	Area in the hypothalamus bounded medially by the mammillothalamic tract and the anterior column of the FORNIX (BRAIN). The medial edge of the INTERNAL CAPSULE and the subthalamic region form its lateral boundary. It contains the lateral hypothalamic nucleus, tuberomammillary nucleus, lateral tuberal nuclei, and fibers of the MEDIAL FOREBRAIN BUNDLE.	Lateral Hypothalamic Area,Lateral Hypothalamic Nucleus,Tuberomammillary Nucleus,Accessory Nucleus of the Ventral Horn,Area Hypothalamica Lateralis,Area Lateralis Hypothalami,Lateral Hypothalamus,Lateral Tuberal Nuclei,Lateral Tuberal Nucleus,Area Hypothalamica Laterali,Area Lateralis Hypothalamus,Area, Lateral Hypothalamic,Areas, Lateral Hypothalamic,Hypothalami, Area Lateralis,Hypothalamic Areas, Lateral,Hypothalamic Nucleus, Lateral,Hypothalamica Laterali, Area,Hypothalamica Lateralis, Area,Hypothalamus, Area Lateralis,Hypothalamus, Lateral,Lateral Hypothalamic Areas,Laterali, Area Hypothalamica,Lateralis Hypothalami, Area,Lateralis Hypothalamus, Area,Lateralis, Area Hypothalamica,Nuclei, Lateral Tuberal,Nucleus, Lateral Hypothalamic,Nucleus, Lateral Tuberal,Nucleus, Tuberomammillary,Tuberal Nuclei, Lateral,Tuberal Nucleus, Lateral
D008297	Male		Males
D010805	Physical Conditioning, Animal	Diet modification and physical exercise to improve the ability of animals to perform physical activities.	Animal Physical Conditioning,Animal Physical Conditionings,Conditioning, Animal Physical,Conditionings, Animal Physical,Physical Conditionings, Animal
D011897	Random Allocation	A process involving chance used in therapeutic trials or other research endeavor for allocating experimental subjects, human or animal, between treatment and control groups, or among treatment groups. It may also apply to experiments on inanimate objects.	Randomization,Allocation, Random
D001835	Body Weight	The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.	Body Weights,Weight, Body,Weights, Body
D003216	Conditioning, Operant	Learning situations in which the sequence responses of the subject are instrumental in producing reinforcement. When the correct response occurs, which involves the selection from among a repertoire of responses, the subject is immediately reinforced.	Instrumental Learning,Learning, Instrumental,Operant Conditioning,Conditionings, Operant,Instrumental Learnings,Learnings, Instrumental,Operant Conditionings
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D000704	Analysis of Variance	A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.	ANOVA,Analysis, Variance,Variance Analysis,Analyses, Variance,Variance Analyses
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001522	Behavior, Animal	The observable response an animal makes to any situation.	Autotomy Animal,Animal Behavior,Animal Behaviors