Recent advances in basic aging research on the nervous system in Japan

Area of Science:

• Neuroscience
• Gerontology

Background:

• Aging affects the nervous system, including neuronal cell death and compensatory mechanisms.
• Key areas of focus include trophic factors, brain cholinergic systems, and the autonomic nervous system.

Purpose of the Study:

• To review recent studies on the aging nervous system.
• To examine age-related changes in neuronal survival, trophic factor effects, and autonomic nervous system function.

Main Methods:

• Retrograde tracer studies on spinal motoneurons.
• Investigation of nerve growth factor (NGF) and acidic fibroblast growth factor (aFGF) effects.
• Microneurography and neurochemical analyses of the autonomic nervous system.

Main Results:

• Differential age effects observed on spinal motoneuron types, with compensatory reactions in surviving neurons.
• NGF effects on certain neurons appear preserved in aged individuals, though controversial.
• aFGF may prevent cholinergic neuron degeneration and improve cognitive function in aged animals.
• Cholinergic system's regulation of cerebral blood flow is maintained in aged rats.
• Increased sympathetic nerve activity and noradrenaline levels noted in aged rats, potentially linked to hypertension.

Conclusions:

• Neuronal survival may correlate with activity, but causality is unclear.
• Trophic factors show potential for neuroprotection and cognitive enhancement in aging.
• Autonomic nervous system alterations in aging may contribute to conditions like hypertension, with species-specific differences observed.