Introduction: Cholinergic neuronal deficiency is one of the main causes of Alzheimer's pathology, which leads to learning and memory impairment. Scopolamine is a muscarinic cholinergic antagonist commonly used to induce Alzheimer's disease (AD). Insulin also regulates learning and memory function. Thus, the aim of this study was to determine the effect of central administration of insulin on pa...

Avoidance is a key characteristic of adaptive and maladaptive fear. Here, we review past and contemporary theories of avoidance learning. Based on the theories, experimental findings and clinical observations reviewed, we distill key principles of how adaptive and maladaptive avoidance behavior is acquired and maintained. We highlight clinical implications of avoidance learning theories and des...

introduction: exposure to 3, 4- methylenedioxymethamphetamine (mdma) could lead to serotonergic system toxicity in the brain. this system is responsible for learning and memory functions. studies show that mdma causes memory impairment dose-dependently and acutely. the present study was designed to evaluate the chronic and acute effects of mdmd on spatial memory and acquisition of passive avoid...

Introduction: The interaction between steroid hormones and neurotransmitters such as GABA has been proved. The regulation of muscimol binding to high-affinity GABAA receptors by estradiol and progesterone has been studied within distinct brain regions using in vitro quantitative autoradiography. There are few studies about the mechanism of the effect of steroid hormones on behaviors such as ...

abstract   introduction: diabetes mellitus accompanies with disturbances in learning, memory, and cognitive skills in the human society and experimental animals. considering the beneficial antidiabetic potential of apium graveolens (ag ), this research study was conducted to evaluate the effect of chronic i.p. administration of ag on learning and memory in diabetic rats using passive avoidance ...

Introduction: The role of serotonergic fibers in avoidance learning is controversial. Involvement of the dorsal raphe nucleus (DRN), the main source of hippocampal projecting serotonergic fibers in acquisition, consolidation and retrieval of passive avoidance (PA) learning, was investigated by functional suppression of this area. Materials and Methods: DRN functional inactivation was done by li...

Definition Learning to avoid aversive outcomes is crucial for survival, and it is ubiquitous in everyday life. This entry focuses on ▶ active avoidance, in which performing a certain behavior prevents an aversive outcome that would otherwise occur. ▶Avoidance learning in that context consists of learning to perform the appropriate behaviors in the appropriate circumstances to prevent aversive o...

BACKGROUND AND OBJECTIVES Conditioned fear may emerge in the absence of directly experienced conditioned stimulus (CS)--unconditioned stimulus (US) pairings. Here, we compared three pathways by which avoidance of the US may be acquired both directly (i.e., through trial-and-error instrumental learning) and indirectly (i.e., via verbal instructions and social observation). METHODS Following fe...