Age-related expression of sigma1 receptors and antidepressant efficacy of a selective agonist in the senescence-accelerated (SAM) mouse.

The sigma1 receptor is a unique intracellular receptor whose activation results in an efficient modulation of several neurotransmitter responses. Its role as a target for the rapid nongenomic effects of neuro(active)steroids and the age-related diminutions in steroid levels suggested that targeting the sigma1 receptor might allow alleviation of age-related neuronal dysfunctions. We examined here the expression and behavioral efficacy of sigma1 receptors in the senescence-accelerated (SAM) mouse model.

Preserved sigma1 (sigma1) receptor expression and behavioral efficacy in the aged C57BL/6 mouse.

The sigma(1) (sigma(1)) receptor represents a unique intracellular neuronal protein modulating several neurotransmitter responses with relevant effects on cognitive functions. We examined here its expression and behavioral efficacy during aging. The sigma(1) receptor expression was examined in young (2 months old) and aged (24 months old) C57BL/6 mouse brain using comparative RT-PCR and immunohistochemistry.

Strain differences in sigma(1) receptor-mediated behaviours are related to neurosteroid levels.

The sigma(1) (sigma(1)) receptor exerts a potent neuromodulatory role in the brain with relevant consequences in memory processes, response to stress, depression and pharmacodependence. Its precise endogenous ligand is not yet identified but the sigma(1) receptor appears to be one target for the nongenomic rapid effects of neuroactive steroids in the brain. The aim of the present study was to establish whether differences in sigma(1) receptor-mediated behaviours could be observed among mouse strains, in relation with differences in either sigma(1) receptor expression or steroid levels.

Involvement of the sigma(1) receptor in cocaine-induced conditioned place preference: possible dependence on dopamine uptake blockade.

The involvement of the sigma(1) receptor on the rewarding effects of cocaine was examined using the conditioned place preference (CPP) procedure in C57BL/6 mice. Acquisition or expression of cocaine (20 mg/kg i.p.