scholarly journals Changes in dam and pup behavior following repeated postnatal exposure to a predator odor (TMT): A preliminary investigation in long-evans rats

2015 ◽  
Vol 58 (2) ◽  
pp. 176-184 ◽  
Author(s):  
Luke W. Ayers ◽  
Arun Asok ◽  
Jennifer Blaze ◽  
Tania L. Roth ◽  
Jeffrey B. Rosen
2020 ◽  
Author(s):  
Laura C. Ornelas ◽  
Ryan E. Tyler ◽  
Preethi Irukulapati ◽  
Sudheesha Paladugu ◽  
Joyce Besheer

AbstractPost-traumatic stress disorder (PTSD) and alcohol use disorder (AUD) are highly comorbid. Additionally, individual differences in response to stress suggest resilient and susceptible populations. The current study exposed male and female Long Evans rats to the synthetically produced predator odor 2,5-dihydro-2,4,5-trimethylthiazoline (TMT) to examine individual differences in stress-reactive behaviors (digging and immobility) and whether these differences could predict lasting consequences of TMT and increases in alcohol drinking. Male and female Long Evans rats were trained on operant alcohol self-administration. After 9 sessions, rats underwent exposure to TMT or water (Control) in a distinct context. 6 days after TMT exposure, rats underwent re-exposure to the TMT-paired context (without TMT), and a series of behavioral assessments (acoustic startle, zero maze, light/dark box), after which rats resumed alcohol self-administration. Rats were divided into two TMT-subgroups using a ratio of digging and immobility behavior during TMT exposure: TMT-subgroup 1 (low digging/immobility ratio) and TMT-subgroup 2 (high digging/immobility ratio). Digging/immobility ratio scores predicted elevated corticosterone levels during TMT exposure and reactivity during context re-exposure in males and females (TMT-subgroup 2), as well as elevated corticosterone levels after context re-exposure and hyperarousal behavior in females (TMT-subgroup 1). Furthermore, TMT stress reactivity predicted increases in alcohol self-administration, specifically in females. These data show that stress-reactivity can predict lasting behavioral changes which may lead to a better understanding of increases in alcohol drinking following stress in females and that individual differences in stress-reactive behaviors using TMT may be helpful to understand resilience/susceptibility to the lasting consequences of stress.HighlightsExposure to the predator odor TMT produces distinct behavioral phenotypes in male and female ratsMale and female high stress reactive rats show enhanced reactivity to the TMT-paired contextStress-reactivity during TMT predicts increases in alcohol self-administration, in femalesStress-reactivity may help to understand resilience/susceptibility and impact on alcohol drinking


2012 ◽  
Vol 229 (1) ◽  
pp. 113-117 ◽  
Author(s):  
R. Hacquemand ◽  
L. Jacquot ◽  
G. Brand

Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs

Investigation of the spontaneous pituitary adenomas in rat have been limited mainly to light microscopic study. Furth et al. (1973) described them as chromophobic, secreting prolactin. Kovacs et al. (1977) in an ul trastructural investigation of adenomas of old female Long-Evans rats, found that they were composed of prolactin cells. Berkvens et al. (1980) using immunocytochemistry at the light microscopic level, demonstrated that some spontaneous tumors of old Wistar rats could contain GH, TSH or ACTH as well as PRL.


Author(s):  
R.P. Apkarian ◽  
J.S. Sanfilippo

The synthetic androgen danazol, is an isoxazol derivative of ethisterone. It is utilized in the treatment of endometriosis, fibrocystic breast disease, and has a potential use as a contraceptive. A study was designed to evaluate the ultrastructural changes associated with danazol therapy in a rat model. The preliminary investigation of the distal segment of the rat uterine horn was undertaken as part of a larger study intended to elucidate the effects of danazol on the female reproductive tract.Cross-sections (2-3 mm in length) of the distal segment of the uterine horn from sixteen Sprague-Dawley rats were prepared for SEM. Ten rats in estrus served as controls and six danazol treated rats were noted to have alterations of the estrus cycle i.e. a lag in cycle phase or noncycling patterns. Specimens were fixed in 3% glutaraldehyde in 0.05M phosphate buffer containing CaCl2 at pH 7.0-7.4 and chilled to 4°C. After a brief wash in distilled water, specimens were passed through a graded series of ethanol, critical point dryed in CO2 from absolute ethanol, and coated with 6nm Au. Observations were made with an IS1-40 SEM operated at 15kV.


Author(s):  
I.C. Murray

In women, hyperprolactinemia is often due to a prolactin (PRL)-secreting adenoma or PRL cell hyperplasia. RRL excess stimulates the mammary glands and causes proliferation of the alveolar epithelium. Bromocriptine, a dopamine agonist, inhibits PRL secretion and is given to women to treat nonpuerperal galactorrhea. Old female rats have been reported to have PRL cell hyperplasia or adenoma leading to PRL hypersecretion and breast stimulation. Herein, we describe the effect of bromocriptine and consequently the reduction in serum PRL levels on the ultrastructure of rat mammary glands.Female Long-Evans rats, 23 months of age, were divided into control and bromocriptine-treated groups. The control animals were injected subcutaneously once daily with a 10% ethanol vehicle and were later divided into a normoprolactinemic control group with serum PRL levels under 30 ng/ml and a hyperprolactinemic control group with serum PRL levels above 30 ng/ml.


Author(s):  
Becky Jackson

Preliminary investigation has indicated similarity in hepatic ultrastructural morphology in nutritional deprivation, and cyanide induced hepatic necrosis. Analysis of hepatic tissue has indicated disruption of intracellular membranes, specifically, reduction in rough endoplasmic reticulum (RER) mitochondrial integrity, and glycogen stores. An increase in smooth endoplasmic reticulum (SER) portion was observed.To further investigate the apparent equivalence of necrotic morphology, ultrastructura1ly, BDF1 mice were subjected to senescence, nutritional deprevation, potassium cyanide (KCN) induced toxemia, and acetaminophen induced toxemia. Controls were utilized to ellucidate non-necrotic hepatocellular normals. U1trastructura1 investigation of controls (Fig. 1) shows densely granular RER, abundant glycogen stores, and morphologically normal mitochondria. Subjects with acetaminophen induced necrosis exhibit reduced normal RER with increased levels of dialated, vesicular RER in apparent conversion to SER (Fig. 2), loss of mitochondrial integrity, and glycogen store reduction. Senescent subjects exhibit a pronounced increase in SER and loss of glycogen store. (Fig. 3). Investigation of the senescent SER at high magnification (Fig. 5) indicates that the SER is arising from degranulating and vesiculating RER.


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