Conditioned enhancement of antibody response against influenza virus hemagglutinin using camphor odor as conditioned stimulus in mice

Objective To observe conditioned enhancement of antibody production against influenza vaccine. Methods 36 female BALB/c mice were injected with 3 μg/mouse influenza virus hemagglutinin (HA) as the unconditioned stimulus (UCS),and camphor odor was served as the conditioned stimulus (CS). After a CS/UCS pairing was made,animals were re-exposed to the CS at Weeks 6. Results Through one conditioned stimulus,the optical density of anti-HA antibody of the conditioned group (Weeks 9:0.68±0.06; Weeks 10:0.60±0.06)was significantly increased compared with the unconditioned group (Weeks 9:0.53±0.06; Weeks 10:0.48±0.04) ( P <0.01). The level of anti-HA antibody of the conditioned group was also significantly greater than other controlled groups( P <0.05). Conclusion Through a single exposure to camphor odor which was paired with immunization of influenza virus HA in a single trial learning protocol,a significant conditioned anti-HA IgG production occurred. Key words: Conditioned enhancement of antibody; Influenza virus hemagglutinin; Camphor odor