title: Chronic mild stress alters the somatostatin receptors in the rat brain.
abstract: BACKGROUND
  The involvement of somatostatin (SST) and its receptors in the pathophysiology of depression and stress has been evidenced by numerous studies.
  
  
  OBJECTIVE
  The purpose of the present study was to find whether chronic mild stress (CMS), an animal model of depression, affects the SST receptors in the rat brain and pituitary, as well as the level of SST in plasma.
  
  
  METHODS
  In CMS model, rats were subjected to 2 weeks of stress and behaviorally characterized using the sucrose consumption test into differently reacting groups based on their response to stress, i.e., stress-reactive (anhedonic), stress-non-reactive (resilient), and invert-reactive rats (characterized by excessive sucrose intake). We measured specific binding of [125I]Tyr3-Octreotide, expression of mRNA encoding sst2R receptors in the rat brains, expression of SST and its receptors in rat pituitary, and the level of SST in the plasma.
  
  
  RESULTS
  The obtained results show decreases in binding of [125I]Tyr3-Octreotide in most of rat brain regions upon CMS and no significant differences between three stressed groups of animals, except for significant up-regulation of sst2 receptor in medial habenula (MHb) in the stress-reactive group. In the same group of animals, significant increase in plasma SST level was observed.
  
  
  CONCLUSIONS
  There are two particularly sensitive sites distinguishing the response to stress in CMS model. In the brain, it is MHb, while on the periphery this predictor is SST level in plasma. These changes may broaden an understanding of the mechanisms involved in the stress response and point to the intriguing role of MHb.
authors.forename: A
authors.initials: A
authors.lastname: Faron-Górecka
authors.forename: M
authors.initials: M
authors.lastname: Kuśmider
authors.forename: M
authors.initials: M
authors.lastname: Kolasa
authors.forename: D
authors.initials: D
authors.lastname: Żurawek
authors.forename: K
authors.initials: K
authors.lastname: Szafran-Pilch
authors.forename: P
authors.initials: P
authors.lastname: Gruca
authors.forename: P
authors.initials: P
authors.lastname: Pabian
authors.forename: J
authors.initials: J
authors.lastname: Solich
authors.forename: M
authors.initials: M
authors.lastname: Papp
authors.forename: M
authors.initials: M
authors.lastname: Dziedzicka-Wasylewska
mesh_terms: D059445:Anhedonia; D000818:Animals; D001923:Brain Chemistry; D002908:Chronic Disease; D005786:Gene Expression Regulation / Q000187:drug effects; D019262:Habenula / Q000378:metabolism; D008297:Male; D015282:Octreotide / Q000031:analogs & derivatives / Q000378:metabolism; D010902:Pituitary Gland / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D017472:Receptors, Interleukin-1 / Q000378:metabolism*; D055500:Resilience, Psychological / Q000187:drug effects; D013315:Stress, Psychological / Q000523:psychology*
chemical_list: D017472:Receptors, Interleukin-1; C000589812:ST2 protein, rat; C045210:3-Tyr-octreotide; D015282:Octreotide