Biology Reference
In-Depth Information
CHAPTER TWO
Role of Electrical Activity of
Neurons for Neuroprotection
Takeshi Morimoto
1
Department of Applied Visual Science, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
1
Corresponding author: e-mail address: takeshi.morimoto@ophthal.med.osaka-u.ac.jp
Contents
1.
Introduction
20
2.
Importance of Neuronal Activity During Normal Development
20
3. CNS Neurons Lose Neuronal Activity After Injury
22
4. Survival-Promoting Effects of Electrical Activity on Neurons
In Vitro
22
4.1 Depolarization
23
4.2 Depolarization and cAMP elevation
23
4.3 Electrical stimulation
24
5. Survival-Promoting Effects of Electrical Activity on Neurons In Vivo
24
5.1 Neuroprotective effect of electrical stimulation on nervous system
25
5.2 Effects of normal physiological stimulation on CNS
27
6. Mechanism of Neuroprotective Effects of Electrical Activity on CNS
29
6.1 Production of neurotrophic factors
29
6.2 Neuronal activity controls cerebral blood flow
29
7. Conclusions: Significance of Activity-Dependent Survival
30
References
32
Abstract
Neurons of the central nervous system (CNS) of adult mammals can be damaged in a
variety of ways. Most neurons rapidly die after injury. Even if the injured CNS neurons
do not die in a short time, the neurons eventually die because they are not able to regen-
erate their axons to reconnect with their normal targets. In addition, neurons are normally
not replaced. Therefore, much work has been directed toward understanding of the mo-
lecular regulation of the CNS degeneration following injury, and different experimental
strategies are being used to try to protect the damaged neurons. Following axonal lesion,
theneurons not onlyneed to survivebut also to reconnect tobe functionally relevant, and
efforts are directed toward not only survival but also axonal regeneration and proper
rewiring of injured neurons. Recent experimental data suggest that electrical activity, en-
dogenous or exogenous, can enhance neuronal survival and regeneration in vitro and
in vivo. This chapter reviews the evidence that have been obtained on the role of
neuronal electrical activity on neuroprotection. We will develop perspectives toward
