LONG-TERM CHANGES INDUCED BY NEONATAL HANDLING IN THE NOCICEPTIVE THRESHOLD AND BODY-WEIGHT IN MICE

During the first 3 weeks of life, four litters of CD-1 male mice were daily handled (HA group) and four other litters were left undisturbed (UHA group). At 35 days of life, mice underwent the tail flick (TF) an d hot plate (HP) tests to measure the baseline reaction to thermal noc iceptive stimulation. At the age of 50, 80, and 140 days body weight w as measured. At the last time point the epididymal fat pads (EFPs) wer e also taken and weighed. We found that, 16 days after the suspension of the manipulation, HA mice showed increased latencies to both nocice ptive tests and, starting on day 80, they began to develop a significa nt increment in body weight. An increase was also evident in EFP weigh t of HA mice.