Physiology & behavior
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Physiology & behavior · Jun 2010
Influence of intracerebral administration of NO agents in dorsal hippocampus (CA1) on cannabinoid state-dependent memory in the step-down passive avoidance test.
In the present study, the effects of nitric oxide agents on WIN55, 212-2 induced state-dependent memory of passive avoidance task were examined in mice. One-trial step-down paradigm was used for the assessment of memory retention in adult male NMRI mice. Post-training intra-CA1 administration of CB1 and CB2 receptor agonists, WIN55, 212-2 (0.25, 0.5 and 1 microg/mouse), dose-dependently decreased memory retrieval. ⋯ Also, in the animals which received both post-training (1 microg/mouse) and pre-test injections of WIN55, 212-2 (1 microg/mouse), the injection of L-NAME (3 microg/mouse, intra-CA1), 2 min before pre-test administration decreased retrieval. Furthermore, in the animals under the influence of post-training administration of WIN55, 212-2 (1 microg/mouse), pre-test co-administration of non-effective doses of WIN55, 212-2 (0.25 microg/mouse) and L-arginine (0.3 and 1 microg/mouse), increased the restoration of memory by pre-test WIN55, 212-2. These findings may demonstrate the involvement of NO in state-dependent memory induced by intra-CA1 administration of WIN55, 212-2.
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Physiology & behavior · Apr 2010
Measuring persistent temporomandibular joint nociception in rats and two mice strains.
Temporomandibular joint (TMJ) pain has been reported to last for prolonged periods in humans. In rodents a variety of methods have been used to measure TMJ nociception, but for most of these methods the period of measurement has been minutes to a couple of hours. In addition, most measurement protocols required restraint or training of the animal. ⋯ In this study C57Bl/6 mice also received TMJ CFA injections, but they did not show a lengthening in any meal pattern or significant increases in IL-1 beta, IL-6 or CGRP. Our data show, for the first time, that meal duration can be used to measure CFA-induced nociception in the TMJ over the course of several weeks in unrestrained rats and for up to seven days in the DBA/1LacJ mouse strain. In addition, C57Bl/6 mice are resistant to CFA-induced TMJ nociception at the same dose used in the DBA/1LacJ mice.
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Physiology & behavior · Mar 2010
Randomized Controlled TrialConditioned effects of caffeine on performance in humans.
There is limited evidence for the conditioning of stimulant-like drug effects to previously-neutral stimuli in humans. Two studies tested whether the facilitatory effects of caffeine on cognitive performance can be conditioned to the context of drug administration. In Experiment 1, sixteen participants were divided equally into two groups: one group (the "paired" group) received 250 mg caffeine in a novel beverage prior to completing two computerized performance tests; the other group (the "unpaired" group) received the same beverage without caffeine (i.e. placebo) before testing. ⋯ After completing the conditioning sessions, tests for conditional responding were conducted by administering placebo in both contexts. During the conditioning phase, caffeine significantly improved reaction time performance relative to placebo, and this advantage was maintained at test in the CS+ context when placebo was administered in both contexts. Therefore the facilitatory effects of caffeine on performance can be elicited, in the absence of drug, by previously-neutral contextual stimuli that have been paired with drug administration.
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Physiology & behavior · Feb 2010
Estradiol reduces anxiety- and depression-like behavior of aged female mice.
Beneficial effects of the ovarian steroid, 17beta-estradiol (E(2)), for affective behavior have been reported in young individuals, but less is known about the effects of E(2) among older individuals, and the capacity of older individuals to respond to E(2) following its decline. In the present study, the effects of acute E(2) administration to aged mice for anxiety-like and depression-like behaviors were investigated. Intact female C57BL/6 mice (N=18) that were approximately 24 months old were administered vehicle (sesame oil, n=9) or E(2) (10 microg, n=9) subcutaneously 1h prior to behavioral testing. ⋯ E(2) also tended to have anti-anxiety effects in the elevated plus maze and Vogel task compared to vehicle administration, but these effects did not reach statistical significance. E(2) did not alter motor behavior and/or coordination in the activity monitor, open field, or rotarod tasks. Thus, an acute E(2) regimen produced specific anti-anxiety and anti-depressant effects, independent of effects on motor behavior, when administered to aged female C57BL/6 mice.
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Physiology & behavior · Jan 2010
Salivary testosterone, cortisol, and progesterone: two-week stability, interhormone correlations, and effects of time of day, menstrual cycle, and oral contraceptive use on steroid hormone levels.
With salivary assessment of steroid hormones increasing, more work is needed to address fundamental properties of steroid hormone levels in humans. Using a test-retest design and radioimmunoassay assessment of salivary steroids, we tested the reliability of testosterone, cortisol, and progesterone levels across two weeks, as well as the effects of oral contraceptives, menstrual cycle phase, and time of day on steroid hormone levels. Testosterone and cortisol were found to be highly reliable in both sexes. ⋯ We explored the interhormone correlations among testosterone, progesterone, and cortisol. All three hormones were positively correlated with one another in men. In women, progesterone was positively correlated with testosterone and cortisol, but testosterone and cortisol were uncorrelated.