Biology Reference
In-Depth Information
Table 1
Commonly used stereological methods (
7,
22
)
Method
Description
Optical Fractionator
Used to estimate the number of objects in a given region of interest; uses
fractionator sampling methods with the
Optical Disector
Physical Fractionator
Used to estimate the number of objects in a given region of interest; uses
fractionator sampling methods; the counting frame and rules deter-
mine which objects are counted
Nucleator
The intersection of rays with the cell surface at a focal plane in which the
nucleus is in focus, is used to estimate the volume (or cross-sectional
area at this focal plane) of the cells
Cavaleri Estimator
Estimates the volume from cross-sectional area, employing Cavaleri's
principle
Fig. 1. The 5-HT thalamocortical fi bers and the differential NeuN + barrel neurons in the barrel fi eld (
a
) is a representative
photomicrograph of the 5-HT (
brown fi bers
)/NeuN (
blue
-
black nuclei
) double labeling at ×5 magnifi cation; (
b
) is a section
at ×100. Scale bar = 100
m
m. (From ref. (
2
) : Reprinted with permission from Elsevier).
the numbers of neurons in the somatosensory cortical barrels
(Fig.
1
) of young adult mice (
2
). Stereology not only provided a
method for estimating the cell numbers and difference between
treatment groups but also allowed for the determination of volume
changes in the given barrel subfi elds. Stereology may be used for
assessing the number of neurons in the human brain postmortem.
One study investigated the number of neurons in the hippocampus
and investigated age-associated alterations (
3
).
As an alternative to purely counting neurons, one may choose to
study neuronal terminals or varicosities. Stereology was used to count
the vesicular glutamate transporters and tyrosine hydroxylase-
immunostained terminals in a study investigating the effect of
chronic or repeated deprivation of alcohol on the dopamine (DA) and
glutamate (GLU) terminals in the extended amygdala (
4
). Immuno-
staining for tyrosine hydroxylase (TH) labeled DA terminals, and
vesicular glutamate transporter 1 (vGLUT1)/vesicular glutamate
transporter 2 (vGLUT2) labeled GLU terminals, which delineated
2.1.2. Quantifying Neuronal
Terminals
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