The role of ␣ 1 -adrenergic receptors (␣ 1 ARs) in cognition and mood is controversial, probably as a result of past use of nonselective agents. ␣ 1A AR activation was recently shown to increase neurogenesis, which is linked to cognition and mood. We studied the effects of long-term ␣ 1A AR stimulation using transgenic mice engineered to express a constitutively active mutant (CAM) form of the ␣ 1A AR. CAM-␣ 1A AR mice showed enhancements in several behavioral models of learning and memory. In contrast, mice that have the ␣ 1A AR gene knocked out displayed poor cognitive function. Hippocampal brain slices from CAM-␣ 1A AR mice demonstrated increased basal synaptic transmission, paired-pulse facilitation, and long-term potentiation compared with wild-type (WT) mice. WT mice treated with the ␣ 1A AR-selective agonist cirazoline also showed enhanced cognitive functions. In addition, CAM-␣ 1A AR mice exhibited antidepressant and less anxious phenotypes in several behavioral tests compared with WT mice. Furthermore, the lifespan of CAM-␣ 1A AR mice was 10% longer than that of WT mice. Our results suggest that long-term ␣ 1A AR stimulation improves synaptic plasticity, cognitive function, mood, and longevity. This may afford a potential therapeutic target for counteracting the decline in cognitive function and mood associated with aging and neurological disorders.

Activation of G protein-coupled ␣ 2 adrenergic receptors (ARs) inhibits epileptiform activity in the hippocampal CA3 region. The specific mechanism underlying this action is unclear. This study investigated which subtype(s) of ␣ 2 ARs and G proteins (G␣ o or G␣ i ) are involved in this response using recordings of mouse hippocampal CA3 epileptiform bursts. Application of epinephrine (EPI) or norepinephrine (NE) reduced the frequency of bursts in a concentration-dependent manner: (Ϫ)EPI Ͼ (Ϫ)NE ϾϾϾ (ϩ)NE. To identify the ␣ 2 AR subtype involved, equilibrium dissociation constants (pK b ) were determined for the selective ␣AR antagonists atipamezole (8.79), rauwolscine (7.75), 2-(2,6-dimethoxyphenoxyethyl)aminomethyl-1,4-benzodioxane hydrochloride (WB-4101; 6.87), and prazosin (5.71). Calculated pK b values correlated best with affinities determined previously for the mouse ␣ 2A AR subtype (r ϭ 0.98, slope ϭ 1.07). Furthermore, the inhibitory effects of EPI were lost in hippocampal slices from ␣ 2A AR-but not ␣ 2C AR-knockout mice. Pretreatment with pertussis toxin also reduced the EPImediated inhibition of epileptiform bursts. Finally, using knock-in mice with point mutations that disrupt regulator of G protein signaling (RGS) binding to G␣ subunits to enhance signaling by that G protein, the EPI-mediated inhibition of bursts was significantly more potent in slices from RGS-insensitive G␣ o G184S heterozygous (G␣ o ϩ/GS) mice compared with either G␣ i2 G184S heterozygous (G␣ i2 ϩ/GS) or control mice (EC 50 ϭ 2.5 versus 19 and 23 nM, respectively). Together, these findings indicate that the inhibitory effect of EPI on hippocampal CA3 epileptiform activity uses an ␣ 2A AR/G␣ o protein-mediated pathway under strong inhibitory control by RGS proteins. This suggests a possible role for RGS inhibitors or selective ␣ 2A AR agonists as a novel antiepileptic drug therapy.

Tricyclic antidepressant (TCA) drugs are used for the treatment of chronic depression, obsessive compulsive disorder (OCD), and anxiety-related disorders. Chronic use of TCA drugs increases the expression of α1-adrenergic receptors (α1-ARs). Yet, it is unclear whether increased α1-AR expression contributes to the antidepressant effects of these drugs or if this effect is unrelated to their therapeutic benefit. In this study, mice expressing constitutively active mutant α1A-ARs (CAM α1A-AR) or CAM α1B-ARs were used to examine the effects of α1A- and α1B-AR signaling on rodent behavioral models of depression, OCD, and anxiety. CAM α1A-AR mice, but not CAM α1B-AR mice, exhibited antidepressant-like behavior in the tail suspension test and forced swim test. This behavior was reversed by prazosin, a selective α1-AR inverse agonist, and mimicked by chronically treating wild type mice with cirazoline, an α1A-AR agonist. Marble burying behavior, commonly used to model OCD in rodents, was significantly decreased in CAM α1A-AR mice but not in CAM α1B-AR mice. In contrast, no significant differences in anxiety-related behavior were observed between wild type, CAM α1A-AR, and CAM α1B-AR animals in the elevated plus maze and light/dark box. This is the first study to demonstrate that α1A- and α1B-ARs differentially modulate antidepressant-like behavior in the mouse. These data suggest that α1A-ARs may be a useful therapeutic target for the treatment of depression.

Tobacco cessation treatments have not been evaluated among Alaska Native (AN) adolescents. This pilot study evaluated the feasibility and acceptability of a targeted cessation intervention developed for AN youth. Intervention components were informed by prior focus groups assessing treatment preferences among AN youth, a social cognitive theoretical framework and feedback obtained from a teen advisory group. The intervention consisted of a weekend program where youth traveled by small airplane from their villages to stay overnight with other adolescents who quit tobacco use together. The program included recreational activities, talking circles, personal stories from elders and teen advisors, and cognitive behavioral counseling. Two intervention pilots were conducted from October 2010 to January 2011 using a non-randomized, uncontrolled study design with assessments at baseline and six-week follow-up. One village in Western Alaska was selected for each pilot with a targeted enrollment of 10 adolescents each. Participants were recruited for each pilot within five days, but recruitment challenges and ‘‘lessons learned’’ are described. The first pilot enrolled nine adolescents (all female) aged 13–16 years; all nine attended the intervention program and 78% (7/9) completed follow-up. The second pilot enrolled 12 adolescents (eight females, four males) aged 12–17 years, of which seven attended the intervention program. Six of these seven participants (86%) completed follow-up. In both pilots, participants rated the intervention as highly acceptable. A targeted cessation intervention was feasible and acceptable to AN youth. The intervention will be tested for efficacy in a subsequent randomized controlled trial.

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