Biology Reference
In-Depth Information
were prepared in DMEM (GIBCO BRL Life-technologies, Gaithersburg, MD,
USA), supplemented with 10% FCS (Boehringer Mannheim, Australia), 5 10
5
2-mercaptoethanol and 100 mg/l kanamycin, which was used as the culture medium
throughout this study. Red blood cells were removed by hypotonic shock. Viable
splenocytes were counted by trypan blue exclusion assay.
Splenocyte suspensions were passed through a G10 column and adherent cells
were eliminated. Nonadherent splenocytes (1 10
6
cells per 2 ml of DMEM
10% FCS) were suspended onto the dishes coated with anti-CD3 mAb (1 g/ml)
(Endogen, Cambridge, MA, USA) and incubated for 24 hours. Interferon- (IFN-)
and interleukin-4 (IL-4) productions in the culture supernatants were measured by
ELISA (Endogen, Cambridge, MA, USA). FITC-conjugated antirat CD4 mAb, CD8
mAb, and PE-conjugated CD45Rc mAb (Endogen, Cambridge, MA, USA) were
used for flow cytometry.
After sacrifice, the rat brains were excised and immersed in PBS containing 10%
formalin and 20% sucrose for 10-14 days. Cryostat sections were prepared and
examined for the position of the electrode tip and ablated areas
[15]
.
Statistics were done using SPSS software.
13.3.3.2 Results
13.3.3.2.1 T-Cell Subpopulations in the Spleen After LH Stimulation
As shown in
Table 13.1
, the percentages of CD4 T cells and CD4CD45Rc T
cells in the LH-stimulated rats were significantly higher than those in the LH sham-
operated rats. No significant changes were detected in any other groups.
13.3.3.2.2 Cytokine Production After LH Stimulation and Destruction
As shown in
Table 13.2
, IFN- production by T cells in LH-stimulated rats was signif-
icantly higher than in the LH sham-operated rats. IL-4 production from the T cells in
the LH-stimulated rats was significantly lower than in the LH sham-operated rats. No
significant changes were detected in any other groups. In addition to stimulation stud-
ies,
Table 13.3
shows that the IFN- production by T cells of the LH-ablated rats was
significantly lower than in the LH sham-operated rats and that IL-4 production from
the T cells in the LH-ablated rats was significantly lower than in the LH sham-operated
rats. No significant changes were detected in any other comparisons or groups.
13.3.4 Reward and Increased T Helper 1 Function
These results strongly suggest that excitation of the LH is linked with reward behav-
ior and that pleasure increases type 1 T-cell functions. Ablation of the LH decreased
Th1 activity and augmented Th2 activity. The direction of the effects of LH treat-
ment on T-cell function coincides nicely with the effects on NK cells. It might now
be safely said that reward links with increased Th1 activity and that, together with
NK cell activity, reward or pleasure plays an important role in anticancer, antiviral,
and cellular immunity via T-cell cytokine production.
