Background-Corticotropin-releasing factor (CRF) and gamma-aminobutyric acid (GABA)ergic systems in the central amygdala (CeA) are implicated in the high-anxiety, high-drinking profile associated with ethanol dependence. Ethanol augments CeA GABA release in ethanol-naive rats and mice.

Nicotine, the main psychoactive ingredient of tobacco, induces negative emotional symptoms during abstinence that contribute to a profound craving for nicotine. However, the neurobiological mechanisms underlying how nicotine produces dependence remains poorly understood. We demonstrate one mechanism for both the anxiety-like symptoms of withdrawal and excessive nicotine intake observed after abstinence, through recruitment of the extrahypothalamic stress peptide corticotropin-releasing factor (CRF) system and activation of CRF1 receptors. Overactivation of the CRF-CRF1 system may contribute to nicotine dependence and may represent a prominent target for investigating the vulnerability to tobacco addiction.abstinence ͉ addiction ͉ amygdala ͉ deprivation ͉ stress

SUMMARY Emerging studies suggest a role for tau in regulating the biology of RNA binding proteins (RBPs). We now show that reducing the RBP T-cell intracellular antigen 1 (TIA1) in vivo protects against neurodegeneration and prolongs survival in transgenic P301S tau mice. Biochemical fractionation shows co-enrichment and co-localization of tau oligomers and RBPs in transgenic P301S tau mice. Reducing TIA1 decreases the number and size of granules co-localizing with stress granule markers. Decreasing TIA1 also inhibits the accumulation of tau oligomers at the expense of increasing neurofibrillary tangles (NFTs). Despite the increase in NFTs, TIA1 reduction increases neuronal survival and rescues behavioral deficits and lifespan. These data provide in vivo evidence that TIA1 plays a key role in mediating toxicity, and further suggest that RBPs direct the pathway of tau aggregation and the resulting neurodegeneration. We propose a paradigm in which dysfunction of the translational stress response leads to tau-mediated pathology.

Dieting to control body weight involves cycles of deprivation from palatable food that can promote compulsive eating. The present study shows that rats withdrawn from intermittent access to palatable food exhibit overeating of palatable food upon renewed access and an affective withdrawal-like state characterized by corticotropin-releasing factor-1 (CRF 1) receptor antagonistreversible behaviors, including hypophagia, motivational deficits to obtain less palatable food, and anxiogenic-like behavior. Withdrawal was accompanied by increased CRF expression and CRF 1 electrophysiological responsiveness in the central nucleus of the amygdala. We propose that recruitment of anti-reward extrahypothalamic CRF-CRF 1 systems during withdrawal from palatable food, analogous to abstinence from abused drugs, may promote compulsive selection of palatable food, undereating of healthier alternatives, and a negative emotional state when intake of palatable food is prevented.eating disorders ͉ obesity ͉ palatability ͉ palatable food dependence ͉ withdrawal F orms of obesity and eating disorders, similar to drug addiction, can be conceptualized as chronic relapsing conditions with alternating periods of abstinence (i.e., dieting to avoid ''forbidden'' palatable foods) and relapse (i.e., compulsive, often uncontrollable, eating of high-palatable foods) that continue despite negative consequences (1). Although the positive reinforcing properties of palatable foods are well known (2, 3), less attention has been given to their negative reinforcing properties (4-6), namely the increased probability of a behavioral response produced by removal of an aversive stimulus (e.g., intake of palatable food to relieve negative emotional states). Intermittent cycles of extended use of drugs of abuse can progressively lead to ''affective dependence,'' observed as a need for higher and/or more regular quantities of the drug to maintain a given emotional set point as well as a negative emotional state upon cessation of drug intake (7,8). Such affective withdrawal may maintain use and motivate relapse via the negative reinforcing properties of continuing and resuming drug use, respectively (7,8).Extrahypothalamic corticotropin-releasing factor (CRF) brain stress systems are putatively involved in the transition from drug use to dependence, during which intake of abused drugs becomes increasingly motivated by these negative, rather than positive, reinforcement mechanisms. CRF plays a motivationally relevant role in withdrawal syndromes for every major drug of abuse, including alcohol, nicotine, cocaine, opiates, amphetamines, and tetrahydrocannabinol (7,8). By analogy, repeated cycles of intermittent, extended access to highly palatable food were hypothesized to induce CRF system neuroadaptations similar to those seen in drug dependence models (4, 5, 9). ResultsIntermittent, extended access to palatable food progressively leads to undereating of less preferred diets when palatable food is not available and to overeating of palatable food upon renewed ...