Chronic response of rat brain norepinephrine and serotonin levels to endurance training

Abstract

Norepinephrine (NE) and serotonin (5-HT) concentrations were determined in three areas of the rat brain following 8 wk exposure to differing physical activity and dietary regimens. Animals were divided into sedentary and exercise groups, and one-half of each received either a normal or atherogenic diet. The exercise consisted of 30 min of treadmill running, 5 days/wk, for 8 wk. Brains were weighed and sectioned into cerebral cortex, cerebellum, and remainder (midbrain), and fluorometrically analyzed for NE and 5-HT content. In most brain areas, NE and 5-HT levels were significantly greater among exercise-normal diet and exercise-fat diet compared to both sedentary groups. In the cerebral cortex, exercise-normal diet rats possessed higher levels of NE and lower concentrations of 5-HT than sedentary animals. The atherogenic diet did not affect amine levels other than 5-HT in the cortex among exercise rats. The NE results are consistent with prior research indicating its control of sympathetic function. Increased levels of 5-HT in the midbrain may be the neurotransmittal adaptation responsible for decreased appetite and enhanced weight loss following chronic endurance exercise.

Endurance training effects on striatal D2 dopamine receptor binding and striatal dopamine metabolites in presenescent older rats

“…More recently, Semenova et al (1981) and Lukaszyk et al (1983) observed that 30 rain exercise in untrained animals increased NE levels in cortex and hippocampus while reducing levels in the hypothalamus; serotonin levels decreased in striatum, cortex and midbrain; DA levels decreased m hypothalamus, striatum, cortex and midbrain. In cerebrum, levels of NE were increased as were levels of serotonin in midbrain following 8 weeks of continuous treadmill running (Brown et al 1979). Similarly, recent studies have suggested that the response to cholinergic blocking drugs is altered by acute and chronic exercise (McMaster and Carney 1985a, b).…”

Effect of Treadmill Exercise on Serotonin Immunoreactivity in Medullary Raphe Nuclei and Spinal Cord Following Sciatic Nerve Transection in Rats

“…Moreover, it is known that exercise training modifies 5-HT activity in different central nervous system regions. Brown [38] observed increased serotonin concentration in rat midbrain and cortex 8 weeks after treadmill exercise training. In addition, 4 weeks swimming training has also increased 5-HT and 5HIAA (main serotonin metabolite) concentrations in the brain stem of trained rats [35].…”

The Effect of Endurance Training on Regional Serotonin Metabolism in the Brain During Early Stage of Detraining Period in the Female Rat

“…There are data showing elevation in resting concentrations, decreases in postexercise content, and elevated turnover of brain 5-HT in endurance-trained rats (Brown et al, 1979;Acworth et al, 1986;Dey et al, 1992;Hoffmann et al, 1994). Human central serotonergic function that was estimated in most experiments by a neuroendocrine response (e.g., by changes in blood prolactin level) was reduced or unaffected by aerobic exercise training (Jakeman et al, 1994;Dwyer and Flynn, 2002).…”