DSP-4 TREATMENT INFLUENCES OLFACTORY PREFERENCES OF DEVELOPING RATS

Control cagemates of rats treated with the norepinephrine (NE) neuroto xin DSP-4 showed normal olfactory learning as infants, but abnormal av ersion to home-cage odors as juveniles. Neither age nor social housing conditions influenced the odor preferences of DSP-3-treated rats: the y showed tolerance or attraction to familiar odors at both development al stages. Controls, but not DSP-4-treated juveniles, housed in mixed treatment groups, showed elevated concentrations of a serotonin metabo lite and reduced NE concentrations in the hippocampus, suggesting that this social situation was particularly stressful for the controls. DS P-4-treated juveniles, but not infants, produced odors that were discr iminable from controls'. Thus, conflicting olfactory signals in the ho me-cages of mixed juvenile groups may have led to the development of s tress in controls. NE depletion appeared to lessen social stress effec ts in their DSP-4-treated cagemates. These findings support other data suggesting that NE modulates the biobehavioral effects of the social environment.