Effects of different intensities of treadmill exercise on cued fear extinction failure, hippocampal BDNF decline, and Bax/Bcl-2 ratio alteration in chronic - morphine treated male rats

Purpose: The basolateral amygdala (BLA) and infralimbic area (IL) of medial prefrontal cortex (mPFC) are two inter-connected brain structures that mediate both fear memory expression and extinction. Besides the well-known role of the BLA in the acquisition and expression of fear memory, projections from IL to BLA inhibit fear expression and have a critical role in fear extinction. However, the details of IL-BLA interaction remain unclear. Here, we aimed to investigate the role of functional reciprocal interactions between BLA and IL in mediating fear memory extinction. Methods: Using lidocaine (LID), male rats underwent unilateral or bilateral inactivation of the BLA and then unilateral intra-IL infusion of CORT, prior to extinction training of auditory fear conditioning paradigm. Freezing behavior was reported as an index for the measurement of conditioned fear. Infusions were performed before the extinction training, allowing to examine the effects on fear expression and also further extinction memory. Experiments 1-3 investigated the effects of left or right infusion of CORT into IL, and LID unilaterally into BLA on fear memory extinction. Results: Results showed that intra-IL infusion of CORT in the right hemisphere reduced freezing behavior when administrated before the extinction training. Auditory fear memory extinction was impaired by asymmetric inactivation of BLA and CORT infusion in the right IL; however, the same effect was not observed with symmetric inactivation of BLA. Conclusion: It is concluded that that the IL-BLA neural circuit may provide additional evidence to contribution of this circuit in auditory fear extinction. This study demonstrate dissociable roles for right or left BLA in subserving the auditory fear extinction. Our finding also raise the possibility that left BLA-IL circuitry may contribute in mediating auditory fear memory extinction via underlying mechanisms, however further research is required.

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236. Biliary excretion of 14C-androstenedione metabolites in control and clofibrate-treated male rats

Journal of Steroid Biochemistry ◽

10.1016/0022-4731(82)90450-2 ◽

1982 ◽

Vol 17 (3) ◽

pp. lxxix

Author(s):

M.E. Beary ◽

V. O'Shea

Keyword(s):

Biliary Excretion ◽

Male Rats ◽

Treated Male

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Orchidectomy selectively increases follicle-stimulating hormone secretion in gonadotropin-releasing hormone antagonist-treated male rats

Acta Endocrinologica ◽

10.1530/eje.0.1320357 ◽

1995 ◽

Vol 132 (3) ◽

pp. 357-362 ◽

Cited By ~ 4

Author(s):

M Tena-Sempere ◽

L Pinilla ◽

E Aguilar

Keyword(s):

Gnrh Antagonist ◽

Follicle Stimulating Hormone ◽

Hormone Secretion ◽

Gonadotropin Releasing Hormone ◽

Male Rats ◽

Gonadotropin Secretion ◽

Releasing Hormone ◽

Treated Male ◽

Lh Secretion ◽

Stimulating Hormone

Tena-Sempere M, Pinilla L, Aguilar E. Orchidectomy selectively increases follicle-stimulating hormone secretion in gonadotropin-releasing hormone agonist-treated male rats. Eur J Endocrinol 1995;132: 357–62. ISSN 0804–4643 The pituitary component of the feedback mechanisms exerted by testicular factors on gonadotropin secretion was analyzed in adult male rats treated with a potent gonadotropin-releasing hormone (GnRH) antagonist. In order to discriminate between androgens and testicular peptides, groups of males were orchidectomized (to eliminate androgens and non-androgenic testicular factors) or injected with ethylene dimethane sulfonate (EDS), a selective toxin for Leydig cells (to eliminate selectively androgens) and treated for 15 days with vehicle or the GnRH antagonist Ac-d-pClPhe-d-pClPhe-d-TrpSer-Tyr-d-Arg-Leu-Arg-Pro-d-Ala-NH2CH3COOH (Org.30276, 5 mg/kg/72 hours). Serum concentrations of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured 7 and 14 days after the beginning of treatment. We found that: in males treated with GnRH antagonist, orchidectomy or EDS treatment did not induce any increase in LH secretion; and orchidectomy, but not EDS treatment, increased FSH secretion in GnRH-treated males. The present results show that negative feedback of testicular factors on LH secretion is mediated completely through changes in GnRH actions. In contrast, a part of the inhibitory action of the testis on FSH secretion is exerted directly at the pituitary level. It can be hypothesized that non-Leydig cell testicular factor(s) inputs at different levels of the hypothalamic–pituitary axis in controlling LH and FSH secretion. Manuel Tena-Sempere, Department of Physiology, Faculty of Medicine, University of Córdoba, 14004 Córdoba, Spain

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Exercise, dietary obesity, and growth in the rat

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1977.232.1.r38 ◽

1977 ◽

Vol 232 (1) ◽

pp. R38-R44 ◽

Cited By ~ 6

Author(s):

G. C. Pitts ◽

L. S. Bull

Keyword(s):

Body Size ◽

High Fat Diet ◽

Treadmill Exercise ◽

Rank Order ◽

Live Weight ◽

Exponential Model ◽

Male Rats ◽

High Fat ◽

Dietary Obesity ◽

Free Body

Four regimens: high-fat diet, exercised (I); chow, exercised (II); high-fat sedentary (III); and chow, sedentary (IV) were initiated in 35-day-old male rats. Growth was exponential in I and II and exponential progressing to rectilinear in III and IV. The exponential model predicted the decreasing rank order in asymptotic weight to be: III, IV, I, II. Body composition data (9 components) showed rank order in masses of fat and the fat-free body mass compartment (FFBM) to be the same as for asymptotic live weight. The rectilinear growth mode probably reflected fat accretion. High-fat diet increased and treadmill exercise decreased FFBM, the latter being reversible. These effects depended on regimen initiations by the 5-7th wk of age. During growth, masses of H2O, muscle, and skin increased as functions of body size; bone as a function of age; and heart, liver, gut, testevity, and diet. Growth in body size was expressed more precisely with FFBM, instead of live weight, as the index of size.

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