Biology Reference
In-Depth Information
the hypothalamus, in the activity of separate components of the immune response.
These investigations demonstrated the important fact that lesioning or destruction
of the hypothalamus and of some other—but by no means all—brain areas affects
immune function.
The development of the concept of multilevel hierarchical organization of the sys-
tem of regulation of immunity opened new prospects for studying the system
[33]
.
This concept stimulated experimental studies of the role of the nervous system in
regulation of bone marrow activity. It was shown for the first time that the brain influ-
ences colony forming in the spleen; in particular, that lesioning of the posterior hypo-
thalamic field decreases the colony-forming activity of bone marrow
[34]
. Similar
disorders develop following craniocerebral trauma
[35]
. Some therapeutic approaches
were attempted to correct or prevent such disorders. The use of melatonin, delargin,
and some other drugs has been proposed
[30,34,36]
.
The possibility of influencing immunological processes by stimulation of
hypothalamic structures was demonstrated for the first time by Groot and Harris
[37]
, who stimulated the tuber cinereum and mamillary bodies in the hypothala-
mus and observed an inhibition of allergic reactions. This was confirmed later by
Szentivanyi, who used an anaphylactic shock model
[38]
. Initial studies investi-
gating the effects of stimulation of the hypothalamic area on blood antibody titers
suggested either stimulatory or suppressive (in case of a high current intensity)
effects
[37-39]
.
An obvious and logical further step in the development of immunophysiology was
to study brain functions during the course of the development of the body's response
to an antigen. The employment of electrophysiological methods in investigation of
this problem was a significant achievement. This approach was pioneered by Braun
[40]
, who showed that the number of active neurons in the hypothalamus, along a
track passing through the posterior hypothalamic area, increased upon immuniza-
tion. Subsequent experiments used mainly electrophysiological methods
[40-44]
and
neurochemical methods to detect changes that occurred in the brain after antigenic
challenges
[45-48]
. These investigators primarily studied activity of hypothalamic
structures and neurons.
The difficulties of obtaining meaningful results by using extracellular analysis of
the impulse activity of neurons made it necessary to use mathematical methods. With
these latter methods, huge amounts of data could be processed to elucidate the dynam-
ics of changes in the activity of hypothalamic neurons after immunization. These stud-
ies established a spatio-temporal pattern of changes in the electrical activity of defined
cerebral structures during the course of the development of body response to anti-
genic challenge. It has been shown that, under natural conditions, the brain becomes
involved in the response to immunization within the first 10-30 minutes after the
introduction of an antigen, and that this involvement is followed by further dynamic
interactions between the nervous and immune systems
[41,43,49,50]
.
These results are of fundamental importance for the understanding of the interac-
tion of the neuroimmune system, because the initial idea of brain influence on immu-
nity gradually developed into the concept of a
neuroimmune regulatory circuit
. With
