How the Brain Works The Facts Visually Explained by DK (z-lib.org)

THE BRAIN OF THE FUTURE

Wiring the Brain 184 185

Wiring the Brain

Vagus nerve stimulation

The vagus nerve, one of the

cranial nerves (see p.12) connects

the brain with organs in the chest

and abdomen. In vagus nerve

stimulation (VNS), a small signal

generator in the chest, similar to

a heart pacemaker, is connected

by wires to electrodes around the

left vagus nerve in the neck. The

nerve’s sensory fibers are stimulated

to send impulses into the brain, where

they are distributed along various

neural pathways. VNS is

mainly used to treat forms

of epilepsy and depression.

Deep brain stimulation (DBS)

In DBS, electrode wires are implanted in various parts

of the brain (see below) to treat a range of disorders.

These send pulses of electricity from a generator and

battery in the chest, connected to the electrodes.

A remote controller adjusts the pulses. In adaptive

DBS, the electrodes have sensors and the generator

automatically responds to the brain’s electrical activity.

Movement disorders

DBS is well established

to treat movement

problems, such as the

tremors and “freezing”

of Parkinson’s disease

and the spasms and

contractions of dystonia.

Psychiatric disorders

DBS may be used in

severe anxiety, depression,

and obsessive-compulsive

disorder, where other

treatments such as drug

medication have not

proved effective.

Cognitive disorders

Research explores DBS

for problems such as

Alzheimer’s disease,

targeting specific

structures involved in

memory and cognitive

neural networks.

Subthalamic

nucleus

Caudate

nucleus

SPINAL CORDSIGNAL GENERATOR

CAROTID

SHEATH

Cable carries

pulse to stimulate

nerve

Subcallosal

cingulate

Globus

pallidus

THE BAT TERIE S USED IN PULSE

GENERATORS FOR DEEP BRAIN

STIMULATION LAST UP TO

ABOUT NINE YEARS

Thalamus Orbitofrontal

cortex

Fornix

Electrodes

wrap around

nerve

Brain releases

neurotransmitters

when stimulated

Signal generator

sends pulses

along cable

WHEN WAS THE

FIRST BIONIC LIMB

CRE ATE D?

In 1993, a team of bioengineers

at the Margaret Rose Hospital

in Edinburgh created the first

bionic arm for amputee

Robert Campbell Aird.

VAGUS NERVE

SPINAL CORD

US_184-185_Wiring_the_brain.indd 185 20/09/2019 12:38