Neurobiology Revision Questions

A1
Neural
development
1.
How
does
the
nervous
system
form
in
a
developing
embryo?
2.
Which
cells
are
the
first
to
become
nerve
cells?
3.
How
do
the
cells
organise
themselves
to
form
a
nervous
system.
4.
What
is
the
role
of
connections
between
neurones
in
the
development
of
the
nervous
system?
5.
What
happens
to
unused
synapses?
6.
What
happens
to
synapses
which
are
used
regularly?
1.
Formation
of
the
Nervous
System
in
a
Developing
Embryo:
The
nervous
system
forms
through
a
process
called
neurulation
during
embryonic
development.
Initially ,
the
ectoderm,
the
outermost
germ
layer
of
the
embryo,
undergoes
thickening
and
forms
a
structure
called
the
neural
plate.
The
neural
plate
then
folds
inward
to
create
a
neural
groove,
which
eventually
fuses
to
form
a
neural
tube.
The
neural
tube
develops
into
the
central
nervous
system,
including
the
brain
and
spinal
cord.
The
surrounding
cells
give
rise
to
the
peripheral
nervous
system.
2.
First
Cells
to
Become
Nerve
Cells:
The
first
cells
to
become
nerve
cells,
or
neurons,
are
called
neuroblasts.
These
are
progenitor
cells
that
arise
from
specialized
cells
in
the
neural
tube
called
neural
stem
cells.
Neuroblasts
undergo
further
differentiation
and
maturation
to
become
fully
functional
neurons. 3.
Self-Organization
of
Cells
in
Nervous
System
Formation:
During
development,
cells
within
the
neural
tube
organize
themselves
in
a
precise
manner
to
form
distinct
regions
and
structures
of
the
nervous
system.
This
process
involves
a
combination
of
intrinsic
genetic
programming
and
extrinsic
cues
from
the
surrounding
environment.
Signaling
molecules
and
gradients
help
guide
the
migration,
differentiation,
and
positioning
of
cells,
ensuring
proper
formation
of
different
regions,
such
as
the
forebrain,
midbrain,
hindbrain,
and
spinal
cord.
4.
Role
of
Connections
between
Neurons
in
Nervous
System
Development:
Connections
between
neurons,
known
as
synapses,
play
a
crucial
role
in
the
development
of
the
nervous
system.
As
neurons
differentiate
and
extend
their
processes
(axons
and
dendrites),
they
establish
connections
with
other
neurons.
This
process
is
guided
by
attractive
and
repulsive
cues,
which
help
direct
the
growth
of
axons
towards
their
appropriate
targets.
The
formation
of
synapses
allows
for
communication
and
signaling
between
neurons,
enabling
the
transmission
of
information
within
the
nervous
system.
5.
Fate
of
Unused
Synapses:
Synapses
that
are
not
used
or
are
not
adequately
engaged
in
neuronal
communication
undergo
a
process
called
synaptic
pruning.
This
is
a
normal
developmental
process
where
unused
synapses
are
eliminated.
The
elimination
of
unused
synapses
helps refine
and
optimize
neural
circuits
by
strengthening
the
connections
that
are
actively
used
while
eliminating
excessive
connections.
6.
Effects
of
Regularly
Used
Synapses:
Synapses
that
are
regularly
used
in
neuronal
communication
undergo
strengthening
and
optimization.
This
process
is
known
as
synaptic
plasticity .
Regular
and
repeated
activation
of
synapses
leads
to
increased
efficiency
in
signal
transmission
and
can
result
in
long-lasting
changes
in
the
strength
of
the
synaptic
connections.
This
phenomenon
underlies
learning,
memory
formation,
and
the
ability
of
the
nervous
system
to
adapt
and
respond
to
experiences.