Biochemical and behavioral effects of carbofuran in goldfish (Carassius auratus)

The effects of concentration (5, 50, and 500 microg/L) and duration (24, 48 h) of exposure to carbofuran, a carbamate insecticide, were assessed on brain catecholamine (norepinephrine [NE] and dopamine), plasma glucose, and hepatic glycogen contents and behavioral activities of goldfish (Carassius auratus). After 24 h of exposure to 50 and 500 microg/L, the level of NE was increased in the olfactory bulbs. The same effect was observed after a 48-h exposure to 500 and 50 microg/L in the telencephalic hemispheres and in the hypothalamus, respectively. An increase in the level of dopamine was also found in hypothalamus after 48 h of exposure to 500 microg/L carbofuran. Plasma glucose increased in concentration after both periods of exposure to carbofuran at 50 and 500 microg/L. Hepatic glycogen concentration decreased after a 48-h exposure to the highest concentration. Behavioral endpoints related to swimming pattern and social interactions were affected after a 24-h exposure to the lowest concentration tested (5 microg/L). The relative sensitivities of these different types of responses to exposure to carbofuran are discussed in light of data on the neurotoxic effects of carbamate and organophosphate insecticides in fish.