<s>
Ponto-geniculo-occipital	B-Algorithm
waves	I-Algorithm
or	O
PGO	B-Algorithm
waves	I-Algorithm
are	O
distinctive	O
wave	O
forms	O
of	O
propagating	O
activity	O
between	O
three	O
key	O
brain	O
regions	O
:	O
the	O
pons	O
,	O
lateral	O
geniculate	O
nucleus	O
,	O
and	O
occipital	O
lobe	O
;	O
specifically	O
,	O
they	O
are	O
phasic	O
field	B-Algorithm
potentials	I-Algorithm
.	O
</s>
<s>
The	O
discovery	O
of	O
PGO	B-Algorithm
waves	I-Algorithm
goes	O
back	O
to	O
1959	O
,	O
when	O
three	O
French	O
scientists	O
released	O
their	O
scientific	O
article	O
of	O
their	O
study	O
of	O
these	O
waves	O
in	O
animal	O
test	O
subjects	O
.	O
</s>
<s>
It	O
was	O
not	O
until	O
the	O
published	O
work	O
of	O
Brooks	O
and	O
Bizzi	O
that	O
these	O
waves	O
became	O
known	O
as	O
PGO	B-Algorithm
waves	I-Algorithm
.	O
</s>
<s>
Their	O
research	O
focused	O
on	O
the	O
propagation	O
of	O
these	O
waves	O
in	O
cats	O
,	O
noticing	O
that	O
these	O
field	B-Algorithm
potentials	I-Algorithm
started	O
in	O
the	O
pons	O
,	O
propagating	O
down	O
to	O
the	O
lateral	O
geniculate	O
nucleus	O
and	O
the	O
occipital	O
lobe	O
.	O
</s>
<s>
Scientists	O
tried	O
to	O
discern	O
whether	O
the	O
rats	O
had	O
PGO	B-Algorithm
waves	I-Algorithm
,	O
but	O
learned	O
that	O
they	O
are	O
present	O
only	O
in	O
the	O
pons	O
,	O
and	O
wave	O
propagation	O
does	O
not	O
excite	O
any	O
neurons	O
in	O
the	O
lateral	O
geniculate	O
nucleus	O
.	O
</s>
<s>
As	O
a	O
result	O
of	O
this	O
study	O
,	O
PGO	B-Algorithm
waves	I-Algorithm
are	O
known	O
as	O
P	O
waves	O
in	O
rodents	O
.	O
</s>
<s>
PGO	B-Algorithm
waves	I-Algorithm
have	O
been	O
studied	O
mostly	O
through	O
cat	O
and	O
rodent	O
animal	O
models	O
.	O
</s>
<s>
Despite	O
the	O
focus	O
of	O
the	O
research	O
,	O
PGO	B-Algorithm
waves	I-Algorithm
have	O
been	O
found	O
to	O
exist	O
in	O
other	O
mammalian	O
species	O
including	O
humans	O
and	O
nonhuman	O
primates	O
,	O
such	O
as	O
the	O
macaque	O
and	O
baboon	O
.	O
</s>
<s>
In	O
the	O
original	O
experiments	O
,	O
PGO	B-Algorithm
waves	I-Algorithm
(	O
or	O
P	O
waves	O
in	O
rodent	O
models	O
)	O
are	O
found	O
by	O
placing	O
electrodes	O
inside	O
the	O
brain	O
,	O
next	O
to	O
either	O
the	O
pons	O
,	O
lateral	O
geniculate	O
nuclei	O
,	O
or	O
occipital	O
lobe	O
.	O
</s>
<s>
Along	O
with	O
electroencephalography	B-Application
(	O
EEG	B-Application
)	O
recording	O
techniques	O
,	O
scientists	O
are	O
also	O
able	O
to	O
show	O
the	O
correlation	O
between	O
other	O
brain	O
waves	O
associated	O
with	O
REM	O
sleep	O
and	O
PGO	B-Algorithm
waves	I-Algorithm
.	O
</s>
<s>
Although	O
scientists	O
know	O
they	O
exist	O
,	O
PGO	B-Algorithm
waves	I-Algorithm
have	O
not	O
been	O
detected	O
in	O
healthy	O
humans	O
due	O
to	O
the	O
ethical	O
concerns	O
about	O
accessing	O
these	O
areas	O
where	O
the	O
readings	O
need	O
to	O
be	O
taken	O
from	O
.	O
</s>
<s>
However	O
,	O
advances	O
in	O
deep	O
brain	O
stimulation	O
has	O
made	O
it	O
possible	O
to	O
put	O
electrodes	O
inside	O
the	O
brains	O
of	O
humans	O
with	O
different	O
pathologies	O
and	O
make	O
EEG	B-Application
recordings	O
of	O
different	O
nuclei	O
.	O
</s>
<s>
Due	O
to	O
the	O
similarities	O
with	O
the	O
animal	O
models	O
,	O
we	O
can	O
infer	O
that	O
PGO	B-Algorithm
waves	I-Algorithm
are	O
happening	O
at	O
the	O
same	O
frequency	O
in	O
human	O
EEGs	B-Application
.	O
</s>
<s>
Thus	O
,	O
scientists	O
can	O
infer	O
that	O
PGO	B-Algorithm
waves	I-Algorithm
exist	O
in	O
humans	O
.	O
</s>
<s>
The	O
neurophysiological	O
studies	O
on	O
PGO	B-Algorithm
waves	I-Algorithm
conclude	O
that	O
the	O
generation	O
of	O
these	O
waves	O
resides	O
in	O
a	O
collection	O
of	O
neurons	O
located	O
in	O
the	O
pons	O
,	O
regardless	O
of	O
species	O
research	O
is	O
done	O
on	O
.	O
</s>
<s>
These	O
neurons	O
are	O
the	O
ones	O
that	O
help	O
to	O
generate	O
and	O
propagate	O
the	O
PGO	B-Algorithm
waves	I-Algorithm
throughout	O
the	O
brain	O
.	O
</s>
<s>
The	O
neuronal	O
cells	O
that	O
allow	O
for	O
the	O
transfer	O
of	O
PGO	B-Algorithm
waves	I-Algorithm
from	O
the	O
pons	O
to	O
the	O
other	O
parts	O
of	O
the	O
brain	O
reside	O
on	O
the	O
rostral	O
portion	O
of	O
the	O
peribrachial	O
area	O
.	O
</s>
<s>
This	O
class	O
of	O
neurotransmitters	O
is	O
what	O
keeps	O
PGO	B-Algorithm
wave	O
amplitudes	O
at	O
very	O
low	O
levels	O
during	O
periods	O
of	O
a	O
mammal	O
being	O
awake	O
.	O
</s>
<s>
Through	O
different	O
studies	O
,	O
these	O
types	O
of	O
neurons	O
have	O
been	O
proven	O
to	O
promote	O
PGO	B-Algorithm
wave	O
generation	O
,	O
thus	O
being	O
an	O
excitatory	O
neuromodulator	O
for	O
triggering	O
neurons	O
.	O
</s>
<s>
In	O
theory	O
,	O
the	O
increase	O
of	O
nitric	O
oxide	O
is	O
seen	O
as	O
an	O
excitatory	O
neuromodulator	O
in	O
PGO	B-Algorithm
wave	O
generation	O
.	O
</s>
<s>
This	O
stems	O
from	O
animal	O
testing	O
that	O
has	O
shown	O
increases	O
in	O
PGO	B-Algorithm
waves	I-Algorithm
as	O
nitric	O
oxide	O
levels	O
were	O
increased	O
in	O
the	O
pons	O
.	O
</s>
<s>
These	O
neurons	O
are	O
theorized	O
to	O
be	O
inhibitory	O
to	O
aminergic	O
neurons	O
,	O
and	O
thus	O
inhibitory	O
to	O
PGO	B-Algorithm
wave	O
propagation	O
.	O
</s>
<s>
The	O
neurons	O
within	O
the	O
vestibular	O
nuclei	O
region	O
of	O
the	O
brain	O
have	O
been	O
shown	O
to	O
provide	O
excitatory	O
bouts	O
of	O
PGO	B-Algorithm
wave	O
generation	O
when	O
stimulated	O
.	O
</s>
<s>
The	O
tests	O
showed	O
that	O
,	O
while	O
the	O
vestibular	O
nuclei	O
aided	O
in	O
creating	O
PGO	B-Algorithm
waves	I-Algorithm
,	O
the	O
excitation	O
of	O
this	O
area	O
of	O
the	O
brain	O
was	O
in	O
no	O
way	O
needed	O
for	O
PGO	B-Algorithm
wave	O
formation	O
.	O
</s>
<s>
The	O
neurons	O
within	O
the	O
amygdala	O
region	O
of	O
the	O
brain	O
have	O
also	O
been	O
shown	O
to	O
provide	O
excitatory	O
bouts	O
of	O
PGO	B-Algorithm
wave	O
generation	O
when	O
electrically	O
stimulated	O
.	O
</s>
<s>
The	O
REM	O
sleep	O
cycle	O
length	O
causes	O
the	O
frequency	O
of	O
PGO	B-Algorithm
waves	I-Algorithm
to	O
be	O
phase	O
locked	O
.	O
</s>
<s>
The	O
use	O
of	O
auditory	O
stimulation	O
has	O
been	O
shown	O
to	O
increase	O
PGO	B-Algorithm
waves	I-Algorithm
during	O
waking	O
and	O
sleeping	O
cycles	O
with	O
neurons	O
associated	O
with	O
transfers	O
of	O
auditory	O
information	O
.	O
</s>
<s>
Even	O
while	O
the	O
subject	O
is	O
awake	O
and	O
in	O
total	O
darkness	O
,	O
the	O
amplitude	O
of	O
PGO	B-Algorithm
waves	I-Algorithm
increases	O
by	O
auditory	O
stimulation	O
.	O
</s>
<s>
Another	O
study	O
also	O
found	O
that	O
auditory	O
stimulation	O
increased	O
the	O
amplitude	O
of	O
PGO	B-Algorithm
waves	I-Algorithm
in	O
slow-wave	O
sleep	O
and	O
REM	O
sleep	O
and	O
did	O
not	O
reduce	O
the	O
amplitude	O
of	O
the	O
waves	O
with	O
repeated	O
auditory	O
stimulation	O
.	O
</s>
<s>
From	O
this	O
research	O
,	O
scientists	O
can	O
theorize	O
that	O
PGO	B-Algorithm
wave	O
generation	O
from	O
auditory	O
stimulation	O
contains	O
a	O
positive-feedback	O
mechanism	O
that	O
can	O
be	O
excited	O
by	O
evoked	O
PGO	B-Algorithm
waves	I-Algorithm
.	O
</s>
<s>
This	O
latter	O
,	O
glutamatergic	O
nucleus	O
is	O
reciprocally	O
connected	O
with	O
the	O
PGO-transferring	O
nuclei	O
of	O
the	O
pons	O
.	O
</s>
<s>
In	O
humans	O
,	O
subthalamic	O
PGO-like	O
waves	O
,	O
that	O
resemble	O
the	O
PGO	B-Algorithm
waves	I-Algorithm
typically	O
recorded	O
in	O
cats	O
,	O
can	O
be	O
recorded	O
during	O
pre-REM	O
and	O
REM	O
sleep	O
.	O
</s>
<s>
This	O
suggests	O
that	O
the	O
subthalamus	O
may	O
play	O
an	O
active	O
role	O
in	O
an	O
ascending	O
activating	O
network	O
implicated	O
in	O
the	O
rostral	O
transmission	O
of	O
PGO	B-Algorithm
waves	I-Algorithm
during	O
REM	O
sleep	O
in	O
humans	O
.	O
</s>
<s>
PGO	B-Algorithm
waves	I-Algorithm
are	O
an	O
integral	O
part	O
of	O
rapid	O
eye	O
movement	O
(	O
REM	O
)	O
sleep	O
.	O
</s>
<s>
As	O
stated	O
earlier	O
,	O
the	O
density	O
of	O
the	O
PGO	B-Algorithm
waves	I-Algorithm
coincides	O
with	O
the	O
amount	O
of	O
eye	O
movement	O
measured	O
in	O
REM	O
sleep	O
.	O
</s>
<s>
This	O
has	O
led	O
some	O
researchers	O
to	O
further	O
theorize	O
about	O
the	O
usefulness	O
of	O
PGO	B-Algorithm
waves	I-Algorithm
for	O
dreaming	O
.	O
</s>
<s>
Basically	O
,	O
the	O
abundance	O
of	O
PGO	B-Algorithm
waves	I-Algorithm
translates	O
into	O
longer	O
periods	O
of	O
REM	O
sleep	O
,	O
which	O
thereby	O
allows	O
the	O
brain	O
to	O
have	O
longer	O
periods	O
where	O
neuronal	O
connections	O
are	O
formed	O
.	O
</s>
<s>
The	O
importance	O
of	O
PGO	B-Algorithm
waves	I-Algorithm
during	O
REM	O
sleep	O
also	O
aids	O
the	O
idea	O
of	O
PGO	B-Algorithm
waves	I-Algorithm
as	O
a	O
signal	O
that	O
a	O
person	O
is	O
dreaming	O
.	O
</s>
<s>
Since	O
dreaming	O
occurs	O
during	O
REM	O
sleep	O
,	O
the	O
PGO	B-Algorithm
waves	I-Algorithm
are	O
theorized	O
to	O
be	O
the	O
signals	O
that	O
make	O
the	O
brain	O
start	O
to	O
recount	O
the	O
experiences	O
from	O
the	O
previous	O
day	O
.	O
</s>
<s>
For	O
more	O
information	O
of	O
the	O
importance	O
of	O
PGO	B-Algorithm
waves	I-Algorithm
during	O
REM	O
sleep	O
,	O
please	O
refer	O
to	O
Activation	O
synthesis	O
theory	O
.	O
</s>
<s>
Another	O
area	O
of	O
potential	O
research	O
interest	O
involves	O
PGO	B-Algorithm
waves	I-Algorithm
during	O
lucid	O
dreaming	O
,	O
active	O
imagination	O
and	O
hallucination	B-General_Concept
.	O
</s>
