Premium
Behavioral effects of neonatal thyroid hormones and differential postweaning rearing in rats
Author(s) -
Sjödén PerOlow,
Lindqvist Mats
Publication year - 1978
Publication title -
developmental psychobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 93
eISSN - 1098-2302
pISSN - 0012-1630
DOI - 10.1002/dev.420110410
Subject(s) - open field , endocrinology , medicine , microgram , hormone , differential effects , psychology , thyroid hormones , differential reinforcement , developmental psychology , reinforcement , biology , in vitro , biochemistry , social psychology
Male and female rats (T rats) given an injection of 75 μg tri‐iodothyronine (T 3 ) and 25 μg thyroxine (T 4 ) on Day 3 after birth were raised under enriched (E) and impoverished (I) postweaning conditions. Observations of their open‐field behavior on Days 63 and 112 revealed a higher rate of activity in T groups as compared to controls (C) as well as faster running times and more entries/min in Hebb‐Williams maze testing on Days 74–86, indicating behavioral hyperactivity in T rats. Active‐avoidance testing at age 91 days revealed a higher number of intertrial crossings and significantly faster unconditioned response and conditioned response latencies in T as compared to C groups. Enriched postweaning rearing altered the behavioral effects in T rats comparatively little, least in the open‐field and more so for escape‐ and avoidance‐latencies and for the number of errors in the Hebb‐Williams maze.