Is There a Time During Neonatal Development for Maximal Imprinting of Odor?

Abstract

During development many changes occur within an organism. Most of these changes are affected both by genetic constraints and environmental influences. Herein we have explored a potential period in development during which animals appear to be maximally sensitive to environmental exposure to odorants. We exposed mice and rats to odorants that should have biological relevance (conspecifíc urine), some relevance (heterospecific urine), or perhaps are irrelevant (androstenone). Regardless of the odorant, exposures resulted in an increase in sensitivity to the stimulus; however, exposures following the time the animals opened their eyes appeared to induce the greatest level of sensitization. Perhaps it is at this time in development that many environmental stimuli take on added salience.