Monitoring neural activities by optical imaging along with the use of genetic modification provides better spatio-temporal resolution to study single neural firing and hence very useful in understanding the neural process and dynamics. This is just a glimpse of few articles reported their outcome of such imaging.

1. Monitoring Neural Activities by
Optical Imaging
Study of neuronal processes include:
 Synaptic Summation
 Dendritic Physiology
 Neural Network Dynamics
Which requires:
 Complex Spatiotemporal control
over neuronal activities
1/31/2015 1Prepared By MD KAFIUL ISLAM

2. Novel Approaches to Monitor and Manipulate
Single Neurons In Vivo (Brecht et al. 2004, JNS)
The combined application of the optical, electrophysiological, and
genetic techniques outlined here will allow us to refine our focus to
the structure and function of identified neurons in the intact brain
Monitoring neurons with improved cellular resolution.
A, Long-term in vivo imaging of GFP-expressing axons in the adult mouse barrel cortex. Note gained (e.g., green
arrowhead), lost (blue arrowhead), and stable (yellow arrowheads) recognized synaptic terminals
B, Ca2+ transients evoked by whisker deflection. Left, A high magnification image of layer 2/3 neurons in vivo (depth, 130m)
in the barrel cortex of a 13-d-old mouse. Right, Line-scan recordings of Ca2+ transients evoked in two neurons by a
deflection of the majority of whiskers on the contra lateral side of the mouse’s snout. The position of the scanned line and
the cells analyzed are indicated (left) 1/31/2015
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Prepared By MD KAFIUL ISLAM

3. Optical monitoring of brain function in
vivo: from neurons to networks (Garaschuk et. al.
2006, EJP)
Here is the review of the multi-cell bolus loading (MCBL) method that involves the use of membrane
permanent fluorescent indicator dyes. It is shown that this approach is useful for the functional analysis of
clusters of neurons and glial cells in vivo. And also MCBL and two-photon imaging can be easily combined
with other labeling techniques, particularly with those involving the use of genetically encoded, green-
fluorescent-protein-based indicators.
Somatic Ca2+ signals in MCBL-stained cells
require action potentials. a Left panel: a merged
image of layer 2/3 cells in the rat somatosensory
cortex stained in vivo with OG-1 AM (green) and
sulforhodamine 101 (red). Neurons are green and
astrocytes are yellow. Right panel: a simultaneous
recording of action potentials in the cell-attached
configuration (upper trace) and associated Ca2+
transients (lower trace) obtained from the neuron
in the middle. The position of pipette is shown by
an arrow.
Sensory-driven Ca2+ transients in individual
cortical neurons. a Individual neurons in the
mouse barrel cortex (left) and the corresponding
Ca2+ transients (right) evoked by the deflection of
the majority of whiskers at the contralateral side
of the snout. The transients were recorded using
the line-scan mode (5 ms/line). The position of the
scanned line is indicated
1/31/2015 3Prepared By MD KAFIUL ISLAM

4. In Vivo Calcium Imaging of Neural
Network Function (Werner et. al. 2007, @APS )
Network activity can be
measured in vivo using
two-photon imaging of
cell populations that
are labeled with
fluorescent calcium
indicators.
1/31/2015 4Prepared By MD KAFIUL ISLAM

5. An Optical Neural Interface: in vivo control of rodent
motor cortex with integrated fiber-optic & opto-
genetic technology (A M Aravanis et al, JNE, 2007)
 Here they report the first in
vivo behavioral demonstration
of a functional optical neural
interface (ONI) in intact
animals, involving integrated
fiberoptic & Optogenetic
technology.
 Channelrhodopsin-2 (ChR2),
an algal light-activated ion
channel has been developed
for
use In mammals, can give rise
to
safe, light-driven stimulation of
CNS neurons on a timescale of
milliseconds. 1/31/2015 Prepared By MD KAFIUL ISLAM 5

6. Multi-site optical excitation using ChR2
and micro-LED array (Grossman et. al. 2010,
JNE)
The recent development of neural
photosensitization tools as ChR2
(Channelrhodopsin-2 ), offers new
opportunities for non-invasive,
flexible
and cell- specific “Neuronal
Stimulation”
Dendritic excitation.
(A) Illumination (1:1) of three
proximal
dendrites and cell soma of ChR2-
expressing hippocampal neuron.
(B) Currents evoked by 10 ms of 1
mW mm−2 illumination.
(C) ChR2-evoked input currents
were synchronized to maximize
spiking 1/31/2015 6Prepared By MD KAFIUL ISLAM

7. Optical Recording of Neuronal Activity With A
Genetically Encoded Calcium Indicator in Anesthetized
& Freely Moving Mice (Lütcke et al.2010, FNC)
Bulk recording of spontaneous &
sensory-
evoked YC3.60 Ca2+ signals in barrel
cortex.(B) Large-area Ca2+ imaging using single-
photon excitation and a camera and
simultaneous local field potential (LFP)
recording in barrel cortex of an
anesthetized mouse and The mean
YC3.60 fluorescence signal (ΔF/F in YFP-
channel; red traces) correlated well with
the LFP for both spontaneous activity (top)
and upon air-puff whisker stimulation
(bottom; dashed vertical lines).
(C) Fiber-optic bulk recording of YC3.60
signals in barrel cortex in an anesthetized
mouse (left schematic). Fluorescence
excitation and detection were both
accomplished through the optical fiber, the
tip of which was placed on the cortical 1/31/2015 7Prepared By MD KAFIUL ISLAM