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 fea...

diabetes mellitus is accompanied with disturbances in learning, memory, and cognitive skills in the humans and experimental animals. due to the anti-diabetic and antioxidant activity of pelargonidin (pg), this research study was conducted to evaluate the efficacy of chronic oral pg on alleviating learning and memory disturbance in streptozotocin-diabetic rats. male wistar rats were divided into...

Introduction: The current study aimed at investigating the existence of the cross state-dependent learning between morphine and scopolamine (SCO) in mice by passive avoidance method, pointing to the role of CA1 area.  Methods: The effects of pre-training SCO (0.75, 1.5, and 3 μg, Intra-CA1), or morphine (1, 3, and 6 mg/kg, intraperitoneal (i.p.) was evaluated on the retrieval of passiv...

There are several conflicting evidences showing the effect of morphine on learning and memory processes. In the present study the effect of chronic morphine administration on passive avoidance, active avoidance and spatial learning and memory of morphine dependent male rats using Passive Avoidance shuttle box and Morris Water Maze tasks were investigated, respectively. Male rats received morphi...

temporal lobe epilepsy (tle) is a disorder of the central nervous system in which hippocampus is mostly involved and causes memory impairment. kindling is a model of inducing epilepsy which is created through pentylenetetrazol (ptz) administration. this study examines the role of the aqueous extract of boswellia on the learning and development of brain (formation of dendritic branches and axons...

these experiments examined the effects of pre-test intra dorsal hippocampus (intra-ca1) administration of gabaa receptor agonist and antagonist, muscimol and bicuculline respectively, on state-dependent learning induced by lithium. male nmri mice were trained in a one-trial step-down inhibitory avoidance task, and immediately after training they received ip injections of either saline (10 ml/kg...

Morphine’s effects on learning and memory processes are well known to depend on synaptic plasticity in the hippocampus. Whereas the role of the hippocampus in morphine-induced amnesia and state-dependent learning is established, the biochemical and molecular mechanisms underlying these processes are poorly understood. The present study intended to investigate whether administration of morphine ...

introduction: the glutamatergic system plays an important role in learning and memory. administration of crocus sativus (saffron) or its constituent, crocin, facilitates the formation of memory. this research investigated the effect of crocin on antagonizing retrograde amnesia induced by ketamine, a glutamatergic receptor antagonist, in rats by shuttle box. methods:  male wistar rats were teste...

background: the cholinergic system plays an important role in learning and memory. administration of crocus sativus (saffron) or its constituent, crocin, facilitates the formation of memory. based on above findings, in the current study the effect of crocin in antagonizing retrograde amnesia induced by scopolamine, a cholinergic receptor antagonist, in rats was investigated by using shuttle box...

Some individuals are better at learning about rewarding situations, whereas others are inclined to avoid punishments (i.e., enhanced approach or avoidance learning, respectively). In reinforcement learning, action values are increased when outcomes are better than predicted (positive prediction errors [PEs]) and decreased for worse than predicted outcomes (negative PEs). Because actions with hi...