A critical review of chronic stress effects on spatial learning and memory
The purpose of this review is to evaluate the effects of chronic stress on hippocampal-dependent function, based primarily upon studies using young, adult male rodents and spatial navigation tasks. Despite this restriction, variability amongst the findings was evident and how or even whether chronic stress influenced spatial ability depended upon the type of task, the […]
Impact of estrogen receptor alpha and beta agonists on delayed alternation in middle-aged rats
Estrogens act in the adult brain to modulate cognition, enhancing performance on some learning tests and impairing performance on others. Our previous research has revealed an impairing effect of chronic 17[beta]-estradiol treatment in young and aged rats on a prefrontally-mediated working memory task, delayed spatial alternation (DSA). Little is known about the mechanisms of these […]
Chronic estradiol replacement impairs performance on an operant delayed spatial alternation task in young, middle-aged, and old rats
The current study examined effects of chronic estradiol replacement on a prefrontally-mediated working memory task at different ages in a rodent model. Ovariectomized young, middle-aged, and old Long-Evans rats were given 5% or 10% 17[beta]-estradiol in cholesterol vehicle via Silastic implants and tested on an operant delayed spatial alternation task (DSA). The two estradiol exposed […]
Chronic treatment with a GPR30 antagonist impairs acquisition of a spatial learning task in young female rats
We hypothesize that the beneficial effects of estradiol on cognitive performance may be mediated through GPR30, a putative membrane target of estrogens. Recently we showed that administration of a selective GPR30 agonist (G-1) to ovariectomized rats enhanced acquisition of a delayed matching-to-position (DMP) T-maze task and increased potassium-stimulated acetylcholine release in the hippocampus, similar to […]
Auditory Memory in Monkeys: Costs and Benefits of Proactive Interference
Proactive interference (PI) has traditionally been understood as an adverse consequence of stimulus repetition during memory tasks. Herein, we present data that emphasize costs as well as benefits of PI for monkeys performing an auditory delayed matching-to-sample (DMTS) task. The animals made same/different judgments for a variety of simple and complex sounds separated by a […]
Voluntary exercise impairs initial delayed spatial alternation performance in estradiol treated ovariectomized middle-aged rats
Estrogens differentially modulate behavior in the adult female rodent. Voluntary exercise can also impact behavior, often reversing age associated decrements in memory processes. Our research group has published a series of papers reporting a deficit in the acquisition of an operant working memory task, delayed spatial alternation (DSA), following 17β-estradiol treatment to middle-aged ovariectomized (OVX) […]
Attenuation of social interaction-associated ultrasonic vocalizations and spatial working memory performance in rats exposed to chronic unpredictable stress
Exposure to unpredictable chronic mild stress (CUS) is a commonly used protocol in rats that is reported to evoke antidepressant-reversible behaviors such as loss of preference for a sweetened water solution which is taken as an analog of the anhedonia seen in major depression. However, the induction of anhedonic-like behavior by chronic mild stress, gauged […]