In a test of this hypothesis, we examined the effects of extinction of food-reinforced lever-pressing on collateral behaviors that might be indices of depression. Operant extinction is known to be aversive to the organism and results in

avoidance behavior. We hypothesized that avoidance of, or withdrawal from, the former source of reward may serve as a marker for “”despair.”" Adult male Wistar rats (n=6-7 animals per group) were exposed to a Skinner box attached to a second compartment of the same size, providing opportunity for the animals to leave the operant chamber and to enter the “”withdrawal”" compartment. NU7441 clinical trial The animals spent a portion of the time during the extinction trials in this second chamber. To assess the predictive validity of this behavior as a potential marker of “”despair,”" we tested the effects of chronic administration of two common antidepressant drugs on this measure. The tricyclic antidepressant imipramine (20 mg/kg) as well as the selective serotonin reuptake inhibitor citalopram (20 mg/kg) reduced the number of entries and time spent in the withdrawal compartment. We propose that entries into and time spent in the withdrawal compartment may operationalize “”avoidance,”" a core symptom of major depression. Rearing as well as biting behaviors during the extinction trials

SHP099 nmr were also attenuated by the antidepressant treatment. These results lend support to the hypothesis that extinction of positively reinforced operants evokes VE-822 cost behaviors that reflect elements of “”despair/depression”" because these behaviors are modulated by antidepressant treatment. The avoidance of the operant chamber as a consequence of extinction, together with rearing and biting behaviors, may serve as useful measures for the testing of antidepressant treatments. (c) 2012 IBRO. Published by Elsevier Ltd. All rights reserved.”
“Potassium channels represent the largest group of pore proteins regulating K+ efflux from the Ktrich inner cell to the extracellular compartment,

thereby inducing changes in the membrane potential. Activity is regulated either by voltage or calcium concentrations, thus the nomenclature of voltage- and calcium-activated potassium channels. The critical role of potassium ion channels in developmental processes remains enigmatic, although it is well accepted that cell differentiation and maturation affect the expression patterns of certain ion channels. Recently, a series of studies delineated the precise function of calcium-activated potassium channels during cardiac, particularly pacemaker, cell development using human and mouse pluripotent stem cell models. It has become evident that this protein family not only regulates proliferation, apoptosis, and cell metabolism but also drives critical events during organ development such as the heart.