title: Effect of subcutaneous injection of estradiol on feeding and drinking behaviors and body weight in basolateral amygdaloid lesioned rats.
abstract: BACKGROUND
  Estradiol is known to inhibit food intake (FI), water intake (WI) and body weight (BW) across the species including women and it is most evident in rats. Ovariectomy in rats and menopause in women produce hyperphagia and obesity. Estradiol substitution in ovariectomized (OVX) rats and hormone replacement in women reverses these changes suggesting that lack of estradiol causes eating related disorders. However, the neurobiological target/s for estradiol mediating effects remains largely unknown. While lesions of basolateral amygdala (BLA) also produce hyperphagia, polydipsia and obesity in female rats suggesting BLA normally inhibits these behaviors.
  
  
  OBJECTIVE
  Since ovariectomy is a useful model to study postmenopausal obesity in women, we have investigated the role of BLA in ovariectomy induced ingestive behaviors.
  
  
  METHODS
  Ovariectomy and stereotaxic lesions in experimental group (n = 6) whereas sham operations in control group (n = 6) were carried out in female rats. Estradiol was injected subcutaneously (s.c) before and after lesions in experimental group and vehicle was injected in control group.
  
  
  RESULTS
  Data from the present study shows that there was an additional increase in FI, WI and BW in OVX animals following BLA lesions, but this additive effect was small compared to sham operated controls. Conversely, OVX rats with lesions have shown small but significant reductions in FI, WI, and lost less BW, following s.c injection of estradiol compared to rats with intact BLA.
  
  
  CONCLUSIONS
  These findings suggest that ovariectomy and estradiol induced changes on ingestive behaviors and body weight are partly mediated via BLA.
authors.affiliation: Department of Physiology, Shri Sathya Sai Medical College and Research Institute, Ammapettai, Kancheepuram (Dist), Tamil Nadu;
authors.forename: Bodepudi N
authors.initials: BN
authors.lastname: Rao
authors.affiliation: Department of Physiology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, INDIA-605006.
authors.forename: Gopal K
authors.initials: GK
authors.lastname: Pal
authors.affiliation: Department of Physiology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry, INDIA-605006.
authors.forename: Pal
authors.initials: P
authors.lastname: Pravati
keywords: BLA; Body weight; Drinking; Estradiol; Feeding