Diazepam fails to potentiate GABA-induced chloride uptake and to produce anxiolytic-like action in aged rats

Nociceptive and anxiety-like behavior in reproductively competent and reproductively senescent middle-aged rats

“…Given that estradiol enhances conversion of progesterone to its neuroactive metabolites as well as amplifies the effects of neuroactive progestins to reduce pain sensitivity,38,65,66 future studies might examine whether some of the observed effects are due to the actions of neurosteroids in the brain. Older individuals generally are less responsive to GABAergic modulators67,68 and may have reduced responses to, or production of, neurosteroids 69–71. This may imply that older rodents in the present study were less sensitive to the modulating effects of (neuro)steroids for nociception, yet were responsive to effects on anxiety behavior if not reproductively senescent.…”

Age-related qualitative shift in emotional behaviour: Paradoxical findings after re-exposure of rats in the elevated-plus maze

“…The paradoxical effect of aging in open arm avoidance, as well as the shift towards a predominant sedative response to benzodiazepines in aged animals, illustrates a qualitative change in emotional behaviour with increasing age that might influence the efficacy of anxiolytic drugs in elder subjects. The present results suggest that alterations in GABA-A receptor activity during the lifespan [41,44] may underlie resistance to conventional anxiolytic agents. Thus, improved treatment outcome in anxiety disorders in older subjects will benefit from the design of pharmacological agents that are customized to meet the challenges of an altered neurochemical substrate during aging.…”

Influence of forced swimming-induced stress on the anxiolytic-like effect of 5HT1A agents in mice

“…Hence, mice underwent one or three 15-min sessions of FS and their behavior was analyzed using the exploratory behavior test (EBT) or the burying behavior test (BBT). Although these models have shown effects that depend on factors such as age (Hascoet et al 2001;López-Rubalcava et al 1996;Wikinski et al 2001), strain (Hascoet et al 2001), previous experience in the same model (Holmes et al 2001), or previous interaction with other rats (Saldivar-Gonzalez et al 2000), both protocols have been broadly validated as useful tools to study changes in anxiety-like behavior of rodents and to screen drugs with anxiolytic potential (Blumstein and Crawley 1983;Crawley and Goodwin 1980;Sanchez 1995;Young and Johnson 1991;Treit 1985;Treit et al 1981). The strain of mice chosen for this study was Swiss Webster, which is a popular mouse strain used for pharmacological tests of anxiety-related behavior (Van Gaalen and Steckler 2000).…”