Hippocampal dysfunctions in tumor-bearing mice.
Brain Behav Immun
; 36: 147-55, 2014 Feb.
Article
in En
| MEDLINE
| ID: mdl-24513875
ABSTRACT
Individuals with cancer are particularly susceptible to depression and cognitive impairment. However, the precise mechanisms underlying cancer-induced hippocampal dysfunction are poorly understood. We investigated the effects of a peripheral tumor on emotional behavior, hippocampus-dependent memory and associated molecular and cellular features using an experimental animal model. Behavioral alterations were examined; stress-related parameters measured; hippocampal neurogenesis evaluated; and the levels of pro-inflammatory cytokines, brain-derived neurotrophic factor (BDNF) and cyclooxygenase-2 (COX-2) assayed, 2 weeks after inoculation of adult BALB/c mice with cells of a colon carcinoma cell line (CT26). As the tumors developed, CT26-inoculated mice showed significant increases in the depression-like behavior (measured using the tail suspension test) and memory impairment (in terms of object recognition) compared with vehicle-inoculated controls. The presence of a peripheral tumor significantly elevated the hippocampal levels of mRNAs encoding interleukin-6 (IL-6) and tumor necrosis factor-α, as well as plasma IL-6 and corticosterone levels. Additionally, the adrenal glands became enlarged, and the numbers of Ki-67-positive proliferating hippocampal cells and doublecortin-positive immature progenitor neurons, as well as the constitutive levels of mRNAs encoding BDNF and COX-2 were significantly reduced. Therefore, a peripheral tumor alone may be sufficient to induce hippocampal dysfunction, possibly by reducing the rate of neurogenesis and the levels of BDNF and COX-2 in that tissue and also by increasing stress-related parameters and the circulating levels of pro-inflammatory cytokines.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Hippocampus
/
Neoplasms, Experimental
Type of study:
Prognostic_studies
Limits:
Animals
Language:
En
Journal:
Brain Behav Immun
Journal subject:
ALERGIA E IMUNOLOGIA
/
CEREBRO
/
PSICOFISIOLOGIA
Year:
2014
Type:
Article