116
2 Holographic Microscopy of Phase and Diffuse Objects …
To estimate the error, there was conducted the study of refraction index distribution of a glass capillary, filled with vaseline oil (R 0 = 75 μm). The data obtained
correspond to the known ones with the accuracy up to 10
−3 , but it is worth pointing
out that the calculation of the same interference pattern for objects with the radius
of 5 μm will reduce accuracy up to ~1.5 × 10
−2 . To enhance the sensitivity of
measurements using the real-time method, a device has been developed containing
a photomultiplier with an analog integrator on precision containers, which, when
located in the recording plane of holographic interferograms, leads to the accumulation of a useful signal on a set of synchronized with a certain phase excitation pulses.
The studies of the refractive index of nerve fibers in in vivo state were carried out
for the first time.
The interferograms obtained in the rhythmic stimulation mode of the internodal segments of nerve fibers and the results of their interpretation are presented
in Fig. 2.17. Recovered images of nerve fibers were observed with magnification up
to 1800×. The refraction index radial distribution study of both myelinated and nonmyelinated nerve fiber in the intravital state was conducted. The results are obtained
from different myelinated fibers and presented in Fig. 2.18.
The character of the dependence n(r) of the myelinated nerve fiber internodal
area has analogy to tubular optical waveguide profile [338] that allows assuming
waveguide characteristics of the myelin sheath and probably of the axon itself. The
data obtained can become the presupposition for detecting remote intercell interaction
mechanism through radiation. In connection with this, it is important to refer to the
work [339], which shows that light is conducted through the stretched cells from
some parts of a plant to another, and the information transmitted in such a way is of
great importance in the development and controlling of all vital functions of a plant.
In our case, an experimentally obtained myelin sheath refraction index that is rather
high for biological structures (1.44 ± 0.01) matches to the morphological data of a
protein-lipoid membrane dense packing of this structure. As is seen in Fig. 2.19, the
axoplasm refraction index on a fiber axis is higher, then in the areas directly under the
myelin sheath. Thus, using the holographic interferometry method, the myelinated
nerve fiber optical characteristics study was conducted. The fiber interferograms with
a diameter of 10 μm with the spatial expansion of more than 1 μm were obtained.
Nerve fiber refraction index profiles were made (the average axon refraction index
is 1.35, the myelin sheath is 1.44). The latter points out the presence of waveguide
Fig. 2.17 Profiles of refraction index of myelinated nerve fibers, defined by the methods of
holographic interferometry. Reprinted from [136] with permission
2 Holographic Microscopy of Phase and Diffuse Objects …
To estimate the error, there was conducted the study of refraction index distribution of a glass capillary, filled with vaseline oil (R 0 = 75 μm). The data obtained
correspond to the known ones with the accuracy up to 10
−3 , but it is worth pointing
out that the calculation of the same interference pattern for objects with the radius
of 5 μm will reduce accuracy up to ~1.5 × 10
−2 . To enhance the sensitivity of
measurements using the real-time method, a device has been developed containing
a photomultiplier with an analog integrator on precision containers, which, when
located in the recording plane of holographic interferograms, leads to the accumulation of a useful signal on a set of synchronized with a certain phase excitation pulses.
The studies of the refractive index of nerve fibers in in vivo state were carried out
for the first time.
The interferograms obtained in the rhythmic stimulation mode of the internodal segments of nerve fibers and the results of their interpretation are presented
in Fig. 2.17. Recovered images of nerve fibers were observed with magnification up
to 1800×. The refraction index radial distribution study of both myelinated and nonmyelinated nerve fiber in the intravital state was conducted. The results are obtained
from different myelinated fibers and presented in Fig. 2.18.
The character of the dependence n(r) of the myelinated nerve fiber internodal
area has analogy to tubular optical waveguide profile [338] that allows assuming
waveguide characteristics of the myelin sheath and probably of the axon itself. The
data obtained can become the presupposition for detecting remote intercell interaction
mechanism through radiation. In connection with this, it is important to refer to the
work [339], which shows that light is conducted through the stretched cells from
some parts of a plant to another, and the information transmitted in such a way is of
great importance in the development and controlling of all vital functions of a plant.
In our case, an experimentally obtained myelin sheath refraction index that is rather
high for biological structures (1.44 ± 0.01) matches to the morphological data of a
protein-lipoid membrane dense packing of this structure. As is seen in Fig. 2.19, the
axoplasm refraction index on a fiber axis is higher, then in the areas directly under the
myelin sheath. Thus, using the holographic interferometry method, the myelinated
nerve fiber optical characteristics study was conducted. The fiber interferograms with
a diameter of 10 μm with the spatial expansion of more than 1 μm were obtained.
Nerve fiber refraction index profiles were made (the average axon refraction index
is 1.35, the myelin sheath is 1.44). The latter points out the presence of waveguide
Fig. 2.17 Profiles of refraction index of myelinated nerve fibers, defined by the methods of
holographic interferometry. Reprinted from [136] with permission