Effects of maternal deprivation on adrenal and behavioural responses in rats with anterodorsal thalami nuclei lesions

Behavioral and hypothalamic‐pituitary‐adrenal responses to anterodorsal thalami nuclei lesions and variable chronic stress in maternally separated rats

“…Additionally, the pattern responses of ambulation and rearing in NMS–VCS animals were seen to resemble those observed in previous work in MS rats (Suárez et al, 2002). It can be argued that maternal separation acts as a chronic stress with permanent behavioral consequences in adult rats.…”

“…With this purpose in mind we analyzed plasma ACTH and CORT, and the open field test under stressful conditions in female rats that were subjected to periodic maternal separation as neonates. Considering previous work (Suárez et al, 2002) we observed an endocrine response after the open field test in MS. In the present study we analyzed whether those responses were maintained under VCS conditions.…”

“…With regard to the ADTN control against the participative role of these nuclei at the CORT level (Suárez et al, 2001, 2002) under VCS, there was no difference between sham and lesioned in either NMS or MS animals, indicating little participation in the circuits activated for CORT release in VCS conditions.…”

“…Two findings showed the brain's plasticity in the utilization of alternative circuits according to the nature of the stressor applied. Maternal separation decreased the ambulation parameter (Suárez et al, 2002), but VCS increased it. The differential modulation of the ADTN is also important in grooming behavior, as in maternally separated rats the lesion increased this parameter (Suárez et al, 2002) but under VCS conditions the lesion decreased it.…”

“…Our previous studies led us to place the anterodorsal thalamic nuclei (ADTN) among the extrahypothalamic limbic centers, which are involved in regulating CORT and adrenal catecholamine secretion or release in rats. Lesions of the ADTN provoked an increase in plasma ACTH, CORT, and NE concentration in non‐maternally separated animals and an increase in plasma ACTH, NE and E concentration in maternally separated animals, which indicates an inhibitory influence of ADTN on adrenal function (Suárez et al, 2002, 2004, 2001).…”