<s>
Subthreshold	B-Algorithm
membrane	I-Algorithm
potential	I-Algorithm
oscillations	I-Algorithm
are	O
membrane	O
oscillations	B-Algorithm
that	O
do	O
not	O
directly	O
trigger	O
an	O
action	B-Algorithm
potential	I-Algorithm
since	O
they	O
do	O
not	O
reach	O
the	O
necessary	O
threshold	O
for	O
firing	O
.	O
</s>
<s>
Neurons	O
produce	O
action	B-Algorithm
potentials	I-Algorithm
when	O
their	O
membrane	O
potential	O
increases	O
past	O
a	O
critical	O
threshold	O
.	O
</s>
<s>
In	O
order	O
for	O
neurons	O
to	O
reach	O
threshold	O
for	O
action	B-Algorithm
potential	I-Algorithm
to	O
fire	O
,	O
enough	O
sodium	O
(	O
Na+	O
)	O
ions	O
must	O
enter	O
the	O
cell	O
through	O
voltage	O
gated	O
sodium	O
channels	O
through	O
membrane	O
and	O
depolarize	O
the	O
cell	O
.	O
</s>
<s>
Once	O
the	O
threshold	O
value	O
is	O
reached	O
,	O
an	O
action	B-Algorithm
potential	I-Algorithm
is	O
produced	O
,	O
causing	O
a	O
rapid	O
increase	O
of	O
Na+	O
enters	O
the	O
cell	O
with	O
more	O
Na+	O
channels	O
along	O
the	O
membrane	O
opening	O
,	O
resulting	O
in	O
a	O
rapid	O
depolarization	O
of	O
the	O
cell	O
.	O
</s>
<s>
However	O
,	O
if	O
the	O
voltage	O
is	O
below	O
the	O
threshold	O
,	O
the	O
neuron	O
does	O
not	O
fire	O
,	O
but	O
the	O
membrane	O
potential	O
still	O
fluctuates	O
due	O
to	O
postsynaptic	B-Algorithm
potentials	I-Algorithm
and	O
intrinsic	O
electrical	O
properties	O
of	O
neurons	O
.	O
</s>
<s>
Therefore	O
,	O
these	O
subthreshold	B-Algorithm
membrane	I-Algorithm
potential	I-Algorithm
oscillations	I-Algorithm
do	O
not	O
trigger	O
action	B-Algorithm
potentials	I-Algorithm
,	O
since	O
the	O
firing	O
of	O
an	O
action	B-Algorithm
potential	I-Algorithm
is	O
an	O
"	O
all-or-nothing	O
"	O
response	O
,	O
and	O
these	O
oscillations	B-Algorithm
do	O
not	O
allow	O
for	O
the	O
depolarization	O
of	O
the	O
neuron	O
to	O
reach	O
the	O
threshold	O
needed	O
,	O
which	O
is	O
typically	O
around	O
-55	O
mV	O
;	O
an	O
"	O
all-or-nothing	O
"	O
response	O
refers	O
to	O
the	O
ability	O
of	O
a	O
neuron	O
to	O
fire	O
an	O
action	B-Algorithm
potential	I-Algorithm
only	O
after	O
reaching	O
the	O
exact	O
threshold	O
.	O
</s>
<s>
For	O
example	O
,	O
figure	O
1	O
depicts	O
the	O
localized	O
nature	O
and	O
the	O
graded	B-Algorithm
potential	I-Algorithm
nature	O
of	O
these	O
subthreshold	B-Algorithm
membrane	I-Algorithm
potential	I-Algorithm
oscillations	I-Algorithm
,	O
also	O
giving	O
a	O
visual	O
representation	O
of	O
their	O
placement	O
on	O
an	O
action	B-Algorithm
potential	I-Algorithm
graph	O
,	O
comparing	O
subthreshold	O
oscillations	B-Algorithm
versus	O
a	O
fire	O
above	O
the	O
threshold	O
.	O
</s>
<s>
These	O
oscillations	B-Algorithm
can	O
produce	O
firing	O
by	O
joining	O
with	O
depolarizations	O
.	O
</s>
<s>
Although	O
subthreshold	O
oscillations	B-Algorithm
do	O
not	O
directly	O
result	O
in	O
neuronal	B-Algorithm
firing	I-Algorithm
,	O
they	O
may	O
facilitate	O
synchronous	O
activity	O
of	O
neighboring	O
neurons	O
.	O
</s>
<s>
All	O
in	O
all	O
,	O
although	O
the	O
subthreshold	B-Algorithm
membrane	I-Algorithm
potential	I-Algorithm
oscillations	I-Algorithm
do	O
not	O
produce	O
action	B-Algorithm
potentials	I-Algorithm
by	O
themselves	O
,	O
through	O
summation	O
,	O
they	O
are	O
able	O
to	O
still	O
impact	O
action	B-Algorithm
potential	I-Algorithm
outcomes	O
.	O
</s>
<s>
Neurons	O
display	O
,	O
beyond	O
synaptic	B-Application
and	O
action	B-Algorithm
potentials	I-Algorithm
,	O
rhythmic	O
subthreshold	B-Algorithm
membrane	I-Algorithm
potential	I-Algorithm
oscillations	I-Algorithm
(	O
a	O
particular	O
type	O
of	O
neural	B-Algorithm
oscillations	I-Algorithm
)	O
.	O
</s>
<s>
These	O
oscillations	B-Algorithm
,	O
which	O
resembled	O
sinusoidal	O
wave	O
forms	O
,	O
were	O
originally	O
discovered	O
in	O
the	O
mammalian	O
inferior	O
olive	O
nucleus	O
cells	O
.	O
</s>
<s>
The	O
functional	O
relevance	O
of	O
subthreshold	O
oscillations	B-Algorithm
concerns	O
the	O
nature	O
of	O
the	O
intrinsic	O
electrical	O
properties	O
of	O
neurons	O
;	O
that	O
is	O
,	O
the	O
electrical	O
responsiveness	O
are	O
not	O
derived	O
from	O
interactions	O
with	O
other	O
cells	O
.	O
</s>
<s>
Subthreshold	O
oscillation	B-Algorithm
frequency	O
can	O
vary	O
,	O
from	O
few	O
Hz	O
to	O
over	O
40Hz	O
,	O
and	O
their	O
dynamic	O
properties	O
have	O
been	O
studied	O
in	O
detail	O
in	O
relation	O
to	O
neuronal	O
activity	O
coherence	O
and	O
timing	O
in	O
CNS	O
,	O
in	O
particular	O
with	O
respect	O
to	O
the	O
10Hz	O
physiological	O
tremor	O
that	O
controls	O
motor	O
execution	O
,	O
Theta	B-Algorithm
rhythm	I-Algorithm
in	O
the	O
entorhinal	O
cortex	O
,	O
<	O
ref	O
name	O
=	O
"	O
:3	O
"	O
>Alonso	O
,	O
A	O
.	O
</s>
<s>
The	O
dynamic	O
aspects	O
of	O
such	O
oscillations	B-Algorithm
have	O
been	O
defined	O
using	O
mathematical	O
modeling	O
.	O
</s>
<s>
The	O
study	O
examined	O
electrophysiological	O
properties	O
and	O
ionic	O
bases	O
of	O
subthreshold	O
oscillation	B-Algorithm
of	O
the	O
membrane	O
potential	O
in	O
104	O
magnocellular	O
neurons	O
of	O
rats	O
,	O
using	O
intracellular	O
recording	O
techniques	O
.	O
</s>
<s>
The	O
study	O
found	O
that	O
SMOP	O
that	O
occurred	O
in	O
all	O
neurons	O
examined	O
were	O
voltage-dependent	O
;	O
oscillation	B-Algorithm
was	O
not	O
a	O
result	O
of	O
excitatory	O
or	O
inhibitory	O
activity	O
and	O
neither	O
was	O
it	O
from	O
an	O
electric	O
coupling	O
.	O
</s>
<s>
This	O
suggests	O
that	O
the	O
subthreshold	O
oscillation	B-Algorithm
of	O
the	O
membrane	O
potential	O
may	O
be	O
crucial	O
for	O
inter-neuronal	O
synchronization	O
of	O
discharge	O
and	O
for	O
the	O
amplification	O
of	O
synaptic	B-Application
events	O
.	O
</s>
<s>
Neurons	O
of	O
a	O
subpopulation	O
of	O
supraoptic	O
neurosecretory	O
cells	O
are	O
able	O
to	O
generate	O
phasic	O
bursts	O
of	O
action	B-Algorithm
potentials	I-Algorithm
.	O
</s>
<s>
In	O
the	O
neurons	O
examined	O
in	O
this	O
experiment	O
,	O
action	B-Algorithm
potentials	I-Algorithm
are	O
succeeded	O
by	O
a	O
depolarizing	O
after-potential	O
.	O
</s>
<s>
GABA	O
,	O
an	O
important	O
neurotransmitter	O
,	O
is	O
involved	O
with	O
modulating	O
synaptic	B-Application
firing	O
within	O
the	O
brain	O
.	O
</s>
<s>
This	O
inhibitor	O
is	O
critical	O
for	O
sustaining	O
subthreshold	B-Algorithm
membrane	I-Algorithm
potential	I-Algorithm
oscillations	I-Algorithm
and	O
for	O
excitatory	O
synaptic	B-Application
impulses	O
.	O
</s>
<s>
Maintaining	O
the	O
equilibrium	O
of	O
GABA	O
presence	O
in	O
the	O
synapse	B-Application
(	O
release	O
and	O
reuptake	O
of	O
GABA	O
)	O
is	O
necessary	O
for	O
these	O
rhythmic	O
subthreshold	B-Algorithm
membrane	I-Algorithm
potential	I-Algorithm
oscillations	I-Algorithm
to	O
occur	O
.	O
</s>
<s>
In	O
addition	O
to	O
neurons	O
firing	O
action	B-Algorithm
potentials	I-Algorithm
,	O
they	O
can	O
also	O
perform	O
synchronized	O
spiking	O
or	O
bursts	O
.	O
</s>
<s>
Subthreshold	B-Algorithm
membrane	I-Algorithm
potential	I-Algorithm
oscillations	I-Algorithm
do	O
not	O
create	O
an	O
action	B-Algorithm
potential	I-Algorithm
;	O
however	O
,	O
neurons	O
do	O
experience	O
bursting	O
when	O
they	O
group	O
together	O
and	O
create	O
a	O
synchronized	O
potential	O
by	O
firing	O
all	O
at	O
once	O
,	O
which	O
is	O
usually	O
the	O
result	O
of	O
these	O
subthreshold	O
potentials	O
.	O
</s>
<s>
Several	O
studies	O
have	O
used	O
various	O
techniques	O
to	O
study	O
the	O
frequency	O
of	O
subthreshold	O
oscillations	B-Algorithm
at	O
a	O
different	O
membrane	O
potential	O
.	O
</s>
<s>
A	O
similar	O
study	O
that	O
did	O
whole-cell	O
recordings	O
of	O
olivary	O
neurons	O
in	O
vivo	O
to	O
investigate	O
the	O
relationship	O
between	O
subthreshold	O
activities	O
and	O
spiking	O
behavior	O
in	O
an	O
intact	O
brain	O
illustrates	O
that	O
the	O
majority	O
of	O
neurons	O
displayed	O
subthreshold	O
oscillation	B-Algorithm
activities	O
.	O
</s>
<s>
Which	O
means	O
that	O
the	O
inferior	O
olive	O
of	O
mammals’	O
brain	O
exhibits	O
relatively	O
stable	O
frequencies	O
settings	O
of	O
oscillations	B-Algorithm
.	O
</s>
<s>
Subthreshold	B-Algorithm
membrane	I-Algorithm
potential	I-Algorithm
oscillations	I-Algorithm
play	O
an	O
important	O
role	O
in	O
the	O
development	O
of	O
the	O
sensory	O
systems	O
,	O
including	O
,	O
but	O
not	O
being	O
limited	O
to	O
the	O
visual	O
system	O
and	O
the	O
olfactory	O
system	O
.	O
</s>
<s>
In	O
the	O
visual	O
system	O
,	O
through	O
the	O
help	O
of	O
electroencephalogram	O
or	O
EEG	O
readings	O
,	O
the	O
subthreshold	B-Algorithm
membrane	I-Algorithm
potential	I-Algorithm
oscillations	I-Algorithm
help	O
equip	O
the	O
cortex	O
for	O
not	O
only	O
processing	O
visual	O
stimulation	O
,	O
but	O
also	O
neuronal	O
plasticity	O
.	O
</s>
<s>
These	O
oscillations	B-Algorithm
are	O
present	O
even	O
before	O
birth	O
and	O
also	O
before	O
a	O
newborn	O
opens	O
its	O
eyes	O
,	O
as	O
they	O
are	O
forms	O
of	O
maturation	O
and	O
preparation	O
of	O
the	O
human	O
sensory	O
cortex	O
,	O
which	O
is	O
a	O
part	O
of	O
the	O
cerebral	O
cortex	O
that	O
is	O
responsible	O
for	O
processing	O
and	O
encoding	O
sensory	O
information	O
.	O
</s>
<s>
In	O
the	O
olfactory	O
system	O
,	O
responsible	O
for	O
sense	O
of	O
smell	O
,	O
according	O
to	O
the	O
study	O
,	O
subthreshold	B-Algorithm
membrane	I-Algorithm
potential	I-Algorithm
oscillations	I-Algorithm
present	O
in	O
mitral	O
cells	O
,	O
which	O
are	O
neurons	O
in	O
the	O
olfactory	O
system	O
,	O
are	O
said	O
to	O
influence	O
the	O
timing	O
of	O
the	O
spikes	B-Algorithm
of	O
action	B-Algorithm
potentials	I-Algorithm
,	O
which	O
in	O
turn	O
allows	O
for	O
the	O
synchronization	O
of	O
multiple	O
mitral	O
cells	O
.	O
</s>
<s>
The	O
study	O
also	O
mentions	O
how	O
this	O
oscillatory	O
activity	O
is	O
thought	O
to	O
also	O
impact	O
excitatory	O
postsynaptic	B-Algorithm
potentials	I-Algorithm
in	O
the	O
way	O
that	O
they	O
act	O
as	O
refinement	O
tools	O
to	O
this	O
post	O
neural	O
activity	O
.	O
</s>
