453
15 FtIR Imaging of tissues: techniques and methods of Analysis
In this section, we introduce the reader to the results of FtIR imaging of the
brain tissue in neurodegenerative disorders such as Alzheimer’s and Parkinson diseases, multiple sclerosis and others, for which the etiology or clinical diagnosis
have not been clearly revealed, and are still the subject of intensive investigations.
From this point of view, the clinical and therapeutic experiments on animal models
and spectral characteristics of pathologically changed brain tissue of humans will
be presented.
Reports on normal brain tissues have demonstrated the ability of FtIR spectroscopy to observe the two main brain tissue types, the grey and white matter, that
are composed of unmyelinated neurons (neural cell bodies) and myelinated axons,
respectively [115, 118]. the myelin sheath around the axon is a lipid-rich layer
(mainly a glycolipid—galactocerebroside). FtIR spectra of the white matter exhibits high absorbance of the lipid vibrations, including bands at ca. 2922, 2852, 1740,
1468, and 1380 cm
−1
attributed to vibrations of the Ch 2 groups as well as ca. 1238
and 1085 cm
−1
originating from the phosphodiester modes. Figure 15.9a depicts an
h&E stained coronal section of normal rat brain tissue showing both the left and
right hemisphere along with a uhCA performed using 8-clusters (15.9b). At eight
clusters many anatomical features can be identified in the normal brain sample.
Five layers are distinguishable in the cortex (yellow–orange–brown–green–brown)
that may correspond to the outermost Brodmann layers. three of the eight clusters
(very-pale blue, red and yellow) corresponded to poor quality spectra that exhibited
strong evidence of mie scattering. the five remaining clusters correspond well with
the tissue structures as follows; a cluster corresponding to the Brodmann layer Iv
in the cortex (green), a cluster containing an inner layer of the cortex and the grey
matter areas in the caudoputamen (brown), a cluster for the white matter spots in
the caudoputamen and most of the basal ganglia (orange), a cluster located in the
lateral portions of the corpus callosum (light blue), and lastly, a cluster located at the
medial portion of the corpus callosum, the commissure anterior and a medial spot in
the basal ganglia (dark blue).
Figure 15.10 shows a h&E section of a section of rat brain tissue with fully
developed tumour along with 2 cluster and 8 cluster uhCA maps. It is clear that in
only 2 clusters the tumour is totally delineated from the rest of the brain. moreover,
one can observe the tumorous cells linking the primary to the secondary cluster,
which is not resolved in the h&E section demonstrating the power of FtIR imaging
combined with uhCA.
Neurodegenerative pathologies such as Alzheimer’s and Parkinson’s diseases,
multiple sclerosis, prion diseases, and epileptic seizures seem to result from similar
cellular and molecular mechanisms, since lipid peroxidation, the formation of inclusions, and protein aggregation are correlated with a change in secondary structure,
which are often associated with disorders of the brain tissue.
one of the hypotheses explaining the cause of Alzheimer’s disease (Ad) is extracellular deposition of β-amyloid peptide (Aβ) in the grey matter of the brain. The
formation of neuritic plaques are associated with folding of Aβ into a β-sheet conformation. In 1996, Choo and co-workers demonstrated the first attempt at detecting β-amyloid protein in human AD brain tissue by using synchrotron infrared
15 FtIR Imaging of tissues: techniques and methods of Analysis
In this section, we introduce the reader to the results of FtIR imaging of the
brain tissue in neurodegenerative disorders such as Alzheimer’s and Parkinson diseases, multiple sclerosis and others, for which the etiology or clinical diagnosis
have not been clearly revealed, and are still the subject of intensive investigations.
From this point of view, the clinical and therapeutic experiments on animal models
and spectral characteristics of pathologically changed brain tissue of humans will
be presented.
Reports on normal brain tissues have demonstrated the ability of FtIR spectroscopy to observe the two main brain tissue types, the grey and white matter, that
are composed of unmyelinated neurons (neural cell bodies) and myelinated axons,
respectively [115, 118]. the myelin sheath around the axon is a lipid-rich layer
(mainly a glycolipid—galactocerebroside). FtIR spectra of the white matter exhibits high absorbance of the lipid vibrations, including bands at ca. 2922, 2852, 1740,
1468, and 1380 cm
−1
attributed to vibrations of the Ch 2 groups as well as ca. 1238
and 1085 cm
−1
originating from the phosphodiester modes. Figure 15.9a depicts an
h&E stained coronal section of normal rat brain tissue showing both the left and
right hemisphere along with a uhCA performed using 8-clusters (15.9b). At eight
clusters many anatomical features can be identified in the normal brain sample.
Five layers are distinguishable in the cortex (yellow–orange–brown–green–brown)
that may correspond to the outermost Brodmann layers. three of the eight clusters
(very-pale blue, red and yellow) corresponded to poor quality spectra that exhibited
strong evidence of mie scattering. the five remaining clusters correspond well with
the tissue structures as follows; a cluster corresponding to the Brodmann layer Iv
in the cortex (green), a cluster containing an inner layer of the cortex and the grey
matter areas in the caudoputamen (brown), a cluster for the white matter spots in
the caudoputamen and most of the basal ganglia (orange), a cluster located in the
lateral portions of the corpus callosum (light blue), and lastly, a cluster located at the
medial portion of the corpus callosum, the commissure anterior and a medial spot in
the basal ganglia (dark blue).
Figure 15.10 shows a h&E section of a section of rat brain tissue with fully
developed tumour along with 2 cluster and 8 cluster uhCA maps. It is clear that in
only 2 clusters the tumour is totally delineated from the rest of the brain. moreover,
one can observe the tumorous cells linking the primary to the secondary cluster,
which is not resolved in the h&E section demonstrating the power of FtIR imaging
combined with uhCA.
Neurodegenerative pathologies such as Alzheimer’s and Parkinson’s diseases,
multiple sclerosis, prion diseases, and epileptic seizures seem to result from similar
cellular and molecular mechanisms, since lipid peroxidation, the formation of inclusions, and protein aggregation are correlated with a change in secondary structure,
which are often associated with disorders of the brain tissue.
one of the hypotheses explaining the cause of Alzheimer’s disease (Ad) is extracellular deposition of β-amyloid peptide (Aβ) in the grey matter of the brain. The
formation of neuritic plaques are associated with folding of Aβ into a β-sheet conformation. In 1996, Choo and co-workers demonstrated the first attempt at detecting β-amyloid protein in human AD brain tissue by using synchrotron infrared