Prolonged
exposure
to
weak
(~1
μT)
extremely-low-frequency
(ELF,
50/60
Hz)
magnetic
fields
has
been
associated
with
an
increased
risk
of
childhood
leukaemia.
One
the
few
biophysical
mechanisms
that
might
account
for
this
link
involves
short-lived
chemical
reaction
intermediates
known
as
radical
pairs.
In
report,
we
use
spin
dynamics
simulations
derive
upper
bound
10
parts
per
million
on
effect
a
1
μT
ELF
field
yield
pair
reaction.
By
comparing
figure
corresponding
effects
changes
in
strength
Earth’s
field,
conclude
if
such
Hz
any
human
biology,
and
results
from
mechanism,
then
should
be
no
greater
than
travelling
kilometres
towards
or
away
geomagnetic
north
south
pole.
Journal of The Royal Society Interface,
Journal Year:
2018,
Volume and Issue:
15(148), P. 20180640 - 20180640
Published: Nov. 1, 2018
Biological
systems
are
dynamical,
constantly
exchanging
energy
and
matter
with
the
environment
in
order
to
maintain
non-equilibrium
state
synonymous
living.
Developments
observational
techniques
have
allowed
us
study
biological
dynamics
on
increasingly
small
scales.
Such
studies
revealed
evidence
of
quantum
mechanical
effects,
which
cannot
be
accounted
for
by
classical
physics,
a
range
processes.
Quantum
biology
is
such
processes,
here
we
provide
an
outline
current
field,
as
well
insights
into
future
directions.
Nature,
Journal Year:
2023,
Volume and Issue:
615(7950), P. 111 - 116
Published: Feb. 22, 2023
Abstract
Many
animals
use
Earth’s
magnetic
field
(also
known
as
the
geomagnetic
field)
for
navigation
1
.
The
favoured
mechanism
magnetosensitivity
involves
a
blue-light-activated
electron-transfer
reaction
between
flavin
adenine
dinucleotide
(FAD)
and
chain
of
tryptophan
residues
within
photoreceptor
protein
CRYPTOCHROME
(CRY).
spin-state
resultant
radical
pair,
therefore
concentration
CRY
in
its
active
state,
is
influenced
by
2
However,
canonical
CRY-centric
radical-pair
does
not
explain
many
physiological
behavioural
observations
2–8
Here,
using
electrophysiology
analyses,
we
assay
magnetic-field
responses
at
single-neuron
organismal
levels.
We
show
that
52
C-terminal
amino
acid
Drosophila
melanogaster
CRY,
lacking
FAD-binding
domain
chain,
are
sufficient
to
facilitate
magnetoreception.
also
increasing
intracellular
FAD
potentiates
both
blue-light-induced
magnetic-field-dependent
effects
on
activity
mediated
C
terminus.
High
levels
alone
cause
blue-light
neuronal
sensitivity
and,
notably,
potentiation
this
response
co-presence
field.
These
results
reveal
essential
components
primary
magnetoreceptor
flies,
providing
strong
evidence
non-canonical
(that
is,
non-CRY-dependent)
pairs
can
elicit
cells.
PRX Life,
Journal Year:
2025,
Volume and Issue:
3(1)
Published: Jan. 16, 2025
A
large
number
of
magnetic
sensors,
like
superconducting
quantum
interference
devices,
optical
pumping,
and
nitrogen
vacancy
magnetometers,
were
shown
to
satisfy
the
energy
resolution
limit.
This
limit
states
that
sensitivity
sensor,
when
translated
into
a
product
with
time,
is
bounded
below
by
Planck's
constant,
ℏ.
bound
implies
fundamental
limitation
as
what
can
be
achieved
in
sensing.
Here
we
explore
biological
particular
three
magnetoreception
mechanisms
thought
underly
animals'
geomagnetic
field
sensing:
radical-pair,
magnetite,
MagR
mechanism.
We
address
question
how
close
these
approach
At
quantitative
level,
utility
it
informs
workings
sensing
model-independent
ways
thus
provide
subtle
consistency
checks
for
theoretical
models
estimated
or
measured
parameter
values,
particularly
needed
complex
systems.
qualitative
closer
ℏ,
more
“quantum”
sensor.
offers
an
alternative
route
towards
understanding
biology
magnetoreception.
It
also
quantifies
room
improvement,
illuminating
nature
has
achieved,
stimulating
engineering
biomimetic
sensors
exceeding
nature's
performance.
Published
American
Physical
Society
2025
Frontiers in Cellular Neuroscience,
Journal Year:
2025,
Volume and Issue:
19
Published: March 4, 2025
In
the
outer
vertebrate
retina,
visual
signal
is
separated
into
intensity
and
wavelength
information.
birds,
seven
types
of
photoreceptors
(one
rod,
four
single
cones,
two
members
double
cone)
mediate
signals
to
>20
second-order
neurons,
bipolar
cells
horizontal
cells.
Horizontal
contribute
color
contrast
processing
by
providing
feedback
feedforward
fish,
reptiles,
amphibians
they
either
encode
or
show
color-opponent
responses.
Yet,
for
bird
number
cell
not
fully
resolved
even
more
importantly,
synapses
between
have
never
been
quantified
any
species.
With
a
combination
light
microscopy
serial
EM
reconstructions,
we
found
different
in
distantly
related
species,
domestic
chicken
European
robin.
agreement
with
some
earlier
studies,
confirmed
highly
abundant
(H1,
H2)
rare
(H3,
H4),
which
H1
an
axon-bearing
cell,
whereas
H2-H4
are
axonless.
made
chemical
one
type
interplexiform
amacrine
at
their
soma.
Dendritic
contacts
H1-H4
were
type-specific
similar
turtle
confirms
high
degree
evolutionary
conservation
retina.
Our
data
further
suggests
that
potentially
H2
may
intensity,
H3
H4
represent
opponent
birds’
superb
and/or
acuity
vision.
Proceedings of the National Academy of Sciences,
Journal Year:
2019,
Volume and Issue:
116(39), P. 19449 - 19457
Published: Sept. 4, 2019
Computational
and
biochemical
studies
implicate
the
blue-light
sensor
cryptochrome
(CRY)
as
an
endogenous
light-dependent
magnetosensor
enabling
migratory
birds
to
navigate
using
Earth's
magnetic
field.
Validation
of
such
a
mechanism
has
been
hampered
by
absence
structures
vertebrate
CRYs
that
have
functional
photochemistry.
Here
we
present
crystal
Columba
livia
(pigeon)
CRY4
reveal
evolutionarily
conserved
modifications
sequence
Trp
residues
(Trp-triad)
required
for
CRY
photoreduction.
In
ClCRY4,
Trp-triad
chain
is
extended
include
fourth
(W369)
Tyr
(Y319)
residue
at
protein
surface
imparts
unusually
high
quantum
yield
These
results
are
consistent
with
observations
night
behavior
in
animals
low
light
levels
could
implications
photochemical
pathways
allowing
magnetosensing.
Journal of The Royal Society Interface,
Journal Year:
2019,
Volume and Issue:
16(158), P. 20190295 - 20190295
Published: Sept. 1, 2019
Birds
can
use
two
kinds
of
information
from
the
geomagnetic
field
for
navigation:
direction
lines
as
a
compass
and
probably
magnetic
intensity
component
navigational
‘map’.
The
appears
to
be
sensed
via
radical
pair
processes
in
eyes,
with
crucial
pairs
formed
by
cryptochrome.
It
is
transmitted
optic
nerve
brain,
where
parts
visual
system
seem
process
respective
information.
Magnetic
perceived
magnetite-based
receptors
beak
region;
ophthalmic
branch
trigeminal
ganglion
brainstem
nuclei.
Yet
spite
considerable
progress
recent
years,
many
details
are
still
unclear,
among
them
their
transformation
into
nervous
signal,
precise
location
centres
brain
combined
other
processes.
Proceedings of the Royal Society B Biological Sciences,
Journal Year:
2024,
Volume and Issue:
291(2016)
Published: Feb. 7, 2024
Migratory
birds
possess
remarkable
accuracy
in
orientation
and
navigation,
which
involves
various
compass
systems
including
the
magnetic
compass.
Identifying
primary
magnetosensor
remains
a
fundamental
open
question.
Cryptochromes
(Cry)
have
been
shown
to
be
magnetically
sensitive,
Cry4a
from
migratory
songbird
seems
show
enhanced
sensitivity
vitro
compared
resident
species.
We
investigate
Cry
their
potential
involvement
magnetoreception
phylogenetic
framework,
integrating
molecular
evolutionary
analyses
with
protein
dynamics
modelling.
Our
analysis
is
based
on
363
bird
genomes
identifies
different
selection
regimes
passerines.
that
characterized
by
strong
positive
high
variability,
typical
characteristics
of
sensor
proteins.
identify
key
sites
are
likely
facilitated
evolution
an
optimized
sensory
for
night-time
songbirds.
Additionally,
we
Cry4
was
lost
hummingbirds,
parrots
Tyranni
(Suboscines),
thus
identified
gene
deletion,
might
facilitate
testing
function
birds.
In
contrast,
other
avian
(Cry1
Cry2)
were
highly
conserved
across
all
species,
indicating
basal,
non-sensory
functions.
results
support
specialization
or
functional
differentiation
songbirds
could
magnetosensation.