Behavioural brain research
-
The effects of curcumin on depressive-like behavior in mice after lipopolysaccharide administration.
Current evidence supports that inflammation and increased cytokine levels are associated with depression-like symptoms and neuropsychological disturbances in humans. Curcumin has anti-inflammatory, antioxidant and anti-depressant-like properties. Here, we examined the effects of curcumin on lipopolysaccharide (LPS)-induced depressive-like behavior and inflammation in male mice. ⋯ Moreover, pre-treatment with curcumin attenuated LPS-induced microglial activation and overproduction of pro-inflammatory cytokine (interleukin-1β and tumor necrosis factor-α), as well as the levels of inducible nitric oxide synthase and cyclooxygenase-2 mRNA in the hippocampus and prefrontal cortex (PFC). In addition, curcumin ameliorated LPS-induced NF-κB activation in the hippocampus and PFC. The results demonstrate that curcumin may be an effective therapeutic agent for LPS-induced depressive-like behavior, partially due to its anti-inflammatory aptitude.
-
The behavioral inhibition system (BIS) and the behavioral activation system (BAS) are two fundamental motivational systems which are not only responsible for affective states, behavior and personality, but also related to predispositions for various forms of psychopathology. A wide range of previous studies revealed sex differences in both BIS/BAS and affective disorders (e.g., anxiety disorder) and externalizing disorders (e.g., addictive and impulsive behaviors), and a close link might exist between them. It remains to be clarified, however, whether the relationships between neuroanatomical characteristics and BIS/BAS exhibit sex differences. ⋯ Results showed that females displayed a negative correlation between BIS sensitivity and rGMV in the parahippocampal gyrus (PHG), as well as positive correlations between BAS sensitivity and rGMV in the ventromedial prefrontal cortex (vmPFC) and inferior parietal lobule (IPL), whereas males showed the opposite pattern. These findings suggest that the brain regions associated with processing of negative emotions (PHG) and reward-related information (vmPFC and IPL) may contribute to sex-related differences in rGMV correlates of BIS and BAS, respectively. The present findings demonstrated the evidence of sex-linked neuroanatomical background of BIS and BAS among non-clinical subjects and might encourage future research into the gender-specific relationships between BIS/BAS and related affective disorders and externalizing disorders.
-
Over the last decade accumulating evidence suggests that brain dopamine (DA) has a role in depression, particularly given the high comorbidity of depression with Parkinson's Disease (PD) and the antidepressant effects of the DA receptor subtype 3 (D3R) agonist pramipexole. The present study assesses the role of D3R in depression. Here we hypothesized that D3R mediates the antidepressant effects of DA. ⋯ Whereas D3R deficient mice did not show significant alterations in locomotion when tested in the openfield, these animals showed anxiety-like symptoms measured as a significant increase in thigmotaxis at the openfield and a significantly lower time spent in the lit compartment at the light/dark exploration test. D3RKO animals also showed depressive-like symptoms as measured by increased immobility time in the Porsolt forced swim test and the tail suspension test, as well as anhedonia measured in the non-motor dependent sucrose test. In conclusion, D3R deficiency results in anxiety-like and depressive-like symptoms that cannot be attributed to motor dysfunction.
-
Within the Pavlovian conditioning framework, extinction is a procedure in which, after conditioning, the conditioned stimulus (CS) is repeatedly presented without the unconditioned stimulus (US). During this procedure the conditioned response (CR) is gradually attenuated. It has been suggested that extinction during the early stages of ontogeny is a qualitatively different process from extinction in adulthood: during infancy, extinction may result in erasure of the memory, while during adulthood extinction involves new learning. ⋯ Extinction produced changes in the expression of freezing, grooming and exploration, and the clearest evidence of spontaneous recovery came from the analysis of freezing behavior. The pattern of behavior observed during extinction is compatible with theoretical approaches which consider different dynamic behavioral systems, and it also fit in well with a molar approach to the analysis of behavior, which considers that extinction involves a transition from one allocation of time among behaviors to another allocation, rather than a loss of strength in any particular discrete response. These results have implications for the study of extinction during infancy, since they are compatible with the hypothesis that the original memory survives extinction, and highlight the importance of control conditions for detecting this effect during this ontogenetic period.