Robert A. Rosellini

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Testosterone (T)'s positive hedonic effects may be mediated by actions of its metabolites, dihydrotestosterone (DHT) or 3alpha-androstanediol (3alpha-diol), in the nucleus accumbens (NA). In Experiment 1, adult, intact, male rats were systemically administered 1 mg of T, DHT, 3alpha-diol or vehicle, at different time points to examine concentrations of(More)
Testosterone (T) and pregnane neurosteroids can enhance conditioned place preference (CPP). The present experiment examined CPP produced by T and its androgenic metabolite dihydrotestosterone (DHT) and 3alpha-Androstanediol (3alpha-diol; an androstane neurosteroid). Administration of 3alpha-diol (>DHT>T) to intact male Long-Evans rats, 1.0 mg daily for six(More)
There has been considerable interest in developing an animal model of the neuropsychological toxicity of chemotherapeutic agents used in the treatment of patients with cancer, especially children, since these agents often cause significant, long-term neuropsychological deficits. Yanovski, Packer, Levine, Davidson, Micalizzi, D'Angio (13) recently proposed(More)
The present experiments examined the role of the serotonergic system in the learned helplessness phenomenon. In Experiment 1, a 200 mg/kg dose of 1-tryptophan injected 30 min prior to testing disrupted acquisition of Fixed Ratio 2 shuttle escape behavior. In Experiment 2, a 100 mg/kg dose of 5-HTP produced interference with the acquisition of the escape(More)
Rats, like dogs, fail to escape following exposure to inescapable shock. This failure to escape does not dissipate in time; rats fail to escape 5 min, 1 hr., 4 hr., 24 hr., and 1 wk. after receiving inescapable shock. Rats that first learned to jump up to escape were not retarded later at bar pressing to escape following inescapable shock. Failure to escape(More)
Exposure to inescapable shock interferes with the subsequent acquisition of an appetitive operant. This deficit may be due to either associative interference or activity reduction from the inescapable shock pretreatment. The relative importance of these two factors was examined by using an appetitive response choice discrimination procedure and concurrently(More)
The extent to which gonadal steroid hormones can serve as unconditioned stimuli in a conditioned taste aversion paradigm was examined in Rockland-Swiss albino mice. With saccharin serving as the conditioned stimulus, subcutaneously injected estradiol benzoate, but not progesterone or testosterone propionate, was found to be a potent unconditioned stimulus(More)
The temporal parameters of environmental enrichment have been examined in two ways. The first is by limiting the total duration of environmental exposure. The effects of this procedure are well documented for both physiology and behavior. The second method is by restricting the daily exposure to environmental enrichment while keeping the days of exposure(More)
Previous research in mice has shown that an uncontrollable stressor, but not a controllable stressor, depresses responding for rewarding electrical stimulation of the brain (ESB) (33). We reexamined this effect in rats by determining rate-intensity functions for rewarding brain stimulation 24 h and 48 h following stressor exposure. In each rat, two(More)
Exposure to inescapable tail shock or foot shock has been shown to produce effects on a number of learning tasks. Tail-shock exposure is also known to influence nociception and morphine reactivity. The present series of experiments investigated the effects of foot shock known to induce learned helplessness effects in our laboratory on the subsequent(More)