Biology Reference
In-Depth Information
5.1.1 Neuroprosthetic electrical stimulation as a neuroprotective device
Advances in microfabrication, microelectronics, material science, wireless
technology, and high-speed computer processing have allowed the develop-
ment of neuroprosthetic devices designed to assist individuals living with
sensory loss and/or motor impairment. The basic premise underlying all neu-
roprosthetic approaches is that targeted and controlled delivery of electrical
stimulation to nerves or muscles can restore physiological function to a dam-
aged organ or limb. The success of cochlear implants, developed over 30 years
ago, is well known. This neuroprosthetic device has helped thousands of pro-
foundly deaf individuals regain hearing and develop speech communication
(
Jones,Harris, Estill, &Mikulec, 2008
). Similarly, advanced artificial limbs have
led to improved mobility and even grasping skills for amputees (
Allin, Baker,
Eckel, & Ramanan, 2010
). The continued development of BMIs is also pro-
viding exciting hope for paralyzed patients. Thus, electrical stimulation of the
nervous systems has become more clinically relevant. These neuroprosthetic
devices may also provide neuroprotection as shown by the cochlear implants
(
Hartshorn et al., 1991; Lousteau, 1987
). Data are being collected on the use
of these advanced devices, and the relationship between neuroprotection
and neuroprostheses will be determined.
5.2. Effects of normal physiological stimulation on CNS
There are other approaches to increase the electrical activity of neurons such
as normal physiological stimulation or environmental stimulation. There is
evidence that normal physiological levels of electrical activity also help reg-
ulate the survival of neurons.
5.2.1 Exercise
Normal physical activity or exercise is related to neuronal activity. The beneficial
effects of exercise on the brain range from neuroprotection to the induction of
neural plasticity (
D¨br¨ssy & Dunnett, 2003; G´mez-Pinilla, Ying, Roy,
Molteni, & Edgerton, 2002
). It also affects the behavior and reduces the neuro-
degenerative symptoms (
Ang, Wong, Mochhala, & Ng, 2003; Cotman &
Berchtold, 2002
). Chronic physical activity increases the expression of brain
growth factors (
Molteni, Ying, & G´mez-Pinilla, 2002; Tong, Shen, Perreau,
Balazs, &Cotman, 2001
). Chronic exercise can increase the expression of genes
that encode several brain neurotrophins, for example, BDNF (
Neeper, Gomez-
Pinilla, Choi, & Cotman, 1995; Oliff, Berchtold, Isackson, & Cotman, 1998
)
and NGF (
Neeper,Gomez-Pinilla,Choi,&Cotman,1996
).
Chronic physical activity can also have neurogenerative and neuro-
protective influences on the brain by stimulating the growth and development
