background sildenafil (viagra) has been introduced to treat erectile dysfunction by acting as phosphodiesterase 5 inhibitor and hence accumulation of guanosine cyclic monophosphate (cgmp). on the other hands, the nitric oxide/cgmp signaling pathway has crucial role in synaptic plasticity processes like long-term potentiation (ltp) in the central nervous system considered as a model of learning ...

one the challenging in hardware performance is to designing a high speed calculating unit. the higher of calculations speeds in a computer system  will be pointed out in terms of performance. as a result, designing a high speed calculating unit is of utmost importance. in this paper, we start design whit this knowledge that one multiplier made of several adder and one divider made of several su...

Introduction: Most of our knowledge regarding the link between opioid dependence and poor cognitive functioning is derived from cross sectional studies.This longitudinal study measured the change in memory functioning following complete abstinence among individuals with heroin dependence. Methods: Using a before-after design,this study followed 30 adults ...

materials and methods in this experimental study, nmri male mice were placed in groups receiving atropine (0.1 and 1 mg/kg), recipient of mgo-n (1, 2.5, and 5 mg/kg) and groups receiving atropine in effective dose and different doses of mgo-n were used. saline was used as a vehicle for drugs in the control groups. memory was evaluated with a step-down apparatus to determine the coming down late...

introduction: working memory plays a critical role in cognitive processes which are central to our daily life. neuroimaging studies have shown that one of the most important areas corresponding to the working memory is the dorsolateral prefrontal cortex (dlfpc). this study was aimed to assess whether bilateral modulation of the dlpfc using a noninvasive brain stimulation, namely transcranial di...

growing evidence suggests that serotonin plays an important role in learning and memory and all its receptors might be implicated in this process. the present study aimed at investigating and comparing the possible involvement of 5-ht 3 and 5-ht 4 receptor (r) agonists/antagonists upon consolidation of inhibitory avoidance memory in the pre-limbic (pl) area. bilateral intra-pl microinjections o...

since anethum graveolens (dill) has phytoestrogenic compounds and it is proven that estrogens exert beneficial effects on cognition; the aim of this study was to understand if this plant can improve memory performance. male balb/c mice weighing 25-30 g were used in this study and memory was assessed by the novel object recognition task. in this method, the difference in the exploration time bet...

abstract: introduction: nitric oxide (no) is a retrograde messenger in hippocampal synaptic plasticity which involves in learning and memory processes. previous studies revealed that hippocampal pyramidal cells contain no synthase (nos) enzyme which produce no and could be a promising target to evaluate the role of no in brain cognitive functions. so in this study, using nos inhibitor (l-name),...

“sources of knowledge” is one of the significant topics in contemporary epistemology. epistemologists accept five sources of knowledge: perception, reason, introspection, testimony, and memory. this paper compares introspection, testimony and memory in mulla sadra and descartes’ philosophical systems. the two philosophers accept introspection, testimony and memory as the sources of knowledge. b...