Interferon-gamma and a factor derived from trypanosomes cause behavioural changes in the rat

Area of Science:

• Neuroscience
• Immunology
• Behavioral Science

Background:

• Interferon-gamma (IFN-gamma) is a cytokine primarily known for its immune functions.
• A novel IFN-gamma immunoreactive molecule, termed "neuronal IFN-gamma", has been identified.
• Trypanosoma brucei brucei can induce IFN-gamma and neuronal IFN-gamma production.

Purpose of the Study:

• To investigate the behavioral effects of intracerebroventricularly administered "neuronal IFN-gamma" and recombinant lymphocyte-derived IFN-gamma in rats.
• To compare the behavioral impact of these two IFN-gamma forms.
• To explore the role of these cytokines in regulating animal behavior.

Main Methods:

• Adult male rats were intracerebroventricularly (i.c.v.) injected with "neuronal IFN-gamma" and lymphocyte-derived IFN-gamma.
• Injections were administered during both light and dark phases of the light/dark cycle.
• Behavioral parameters, including rearing and locomotion, were monitored.

Main Results:

• Both "neuronal IFN-gamma" and lymphocyte-derived IFN-gamma significantly reduced the frequency and duration of rearing and locomotion.
• These behavioral effects were observed exclusively during the dark phase of the light/dark cycle.
• An extract from Trypanosoma brucei brucei also induced a reduction in rearing during the dark phase, though to a lesser extent.

Conclusions:

• "Neuronal IFN-gamma" exhibits behavioral effects similar to lymphocyte-derived IFN-gamma.
• These findings suggest that IFN-gamma, including its neuronal form, may play a role in modulating animal behavior.
• The study highlights the potential involvement of these cytokines in behavioral disturbances.