Connection Between Dopamine, Noradrenaline, and Hippocampal Activity During Mild Exercise

Recent research from the University of Tsukuba has unveiled the involvement of monoamine neurotransmitters, specifically dopamine and noradrenaline, in activating the hippocampus during light physical activity. This study, published in The FASEB Journal, indicates that even minimal exercise, such as light jogging and yoga, can stimulate the hippocampus, which is crucial for enhancing neuronal growth and memory function.

The precise mechanisms through which light exercise influences brain function, particularly the specific neural pathways activated, have remained largely unexplored. The researchers focused on dopamine, noradrenaline, and serotonin, collectively referred to as monoamines. These neurotransmitters are essential for modulating neuronal activity and promoting synaptic plasticity, and they originate from clusters of neurons located in the brainstem.

To investigate the hypothesis that the monoaminergic system from the brainstem contributes to hippocampal activation during physical activity, the research team employed a rat treadmill model designed to replicate human exercise responses. They assessed the impact of varying exercise intensities on the concentrations of monoamines in the hippocampus, alongside the activation of brainstem monoaminergic neurons.

The findings revealed that both dopamine and noradrenaline levels in the hippocampus increased as a result of light exercise. Additionally, the activation of dopamine-producing neurons in the ventral tegmental area and noradrenaline-producing neurons in the locus coeruleus--key sources of these neurotransmitters--was confirmed. This activation was found to be positively correlated with neuronal activity in the hippocampus.

Consequently, the study suggests that dopamine from the ventral tegmental area and noradrenaline from the locus coeruleus play a significant role in the neural circuits that facilitate hippocampal activation during mild physical activity. Further investigations are necessary to elucidate the neural circuit mechanisms that enhance memory function through light exercise and to bolster the efficacy of exercise prescriptions aimed at improving cognitive function and brain plasticity.