Calcium homeostasis in aged neurones

Area of Science:

• Neuroscience
• Cell Biology
• Aging Research

Background:

• Cytoplasmic calcium homeostasis is crucial for neuronal function.
• Age-related changes in neuronal physiology are not fully understood.
• Calcium dysregulation is implicated in neurodegenerative processes.

Purpose of the Study:

• To investigate age-associated alterations in cytoplasmic calcium homeostasis in neurons.
• To compare calcium handling in peripheral and central neurons across different age groups.
• To elucidate the impact of aging on neuronal calcium signaling dynamics.

Main Methods:

• Isolation of peripheral and central neurons from rats of different ages (neonatal, adult, old).
• Preparation of cerebellar slices from adult and old mice.
• Measurement of cytoplasmic calcium concentration ([Ca2+]i) using indo-1/fura-2 microfluorimetry.
• Assessment of depolarization-induced calcium transients and calcium release from endoplasmic reticulum stores.

Main Results:

• Senile neurons exhibited significantly higher resting [Ca2+]i.
• Old neurons showed decreased amplitudes, prolonged rising phases, and slower recovery of [Ca2+]i transients upon depolarization.
• Calcium release from endoplasmic reticulum stores diminished in old central neurons but not peripheral neurons.

Conclusions:

• Neuronal aging is associated with significant disruptions in calcium homeostasis mechanisms.
• These changes result in elevated resting [Ca2+]i and prolonged calcium signals.
• Aged neurons demonstrate impaired calcium load handling, potentially increasing their susceptibility to calcium toxicity.