POSTNATAL HANDLING REDUCES ANXIETY AS MEASURED BY EMOTIONALITY RATINGAND HYPONEOPHAGIA TESTS IN FEMALE RATS

The present studies evaluated the short- and long-lasting effects of p ostnatal handling (administered during the first 21 days of life) on t he emotional behavior of female Sprague-Dawley rats. The performance o f postnatally handled (H) and control nonhandled (NH) animals was comp ared in two different situations: an emotionality rating (ER) test (wh en they were 40 days or 4 months old), and a hyponeophagia (neophobia) test of anxiety, at the age of 4 months. The results showed that post natal handling induced both short-term and long-term reductions of spo ntaneous emotional reactivity in the ER test, although the effects on some measures disappeared in 4-month-old rats. Postnatal handling also induced enduring decreases of anxiety as measured by the hyponeophagi a test. None of the observed effects were attributable to changes in b asal locomotor activity. ER measures were significantly related to hyp oneophagia, because animals showing the highest emotionality scores in the ER test (preferentially NH animals) were those that showed the hi ghest eating latencies and spent less time eating in the neophobic sit uation (i.e., hyponeophagia test).