Effect of FR121196, a novel cognitive enhancer, on the memory impairment of rats in passive avoidance and radial arm maze tasks.

Passive avoidance performance was impaired in young rats by scopolamine (1.0 mg/kg) or by nucleus basalis magnocellularis lesions and in aged rats (24-26 months old). FR121196[N-(4-acetyl-1-piperazinyl)-4-fluorobenzenesulfonamide+ ++], a newly introduced cognitive enhancer, ameliorated the failure in memory retention with bell-shaped dose-response curves in doses ranging from 0.1 to 10 mg/kg. Similar dose-response curves also were obtained with methamphetamine (0.1-10 mg/kg), whereas physostigmine (0.01-1.0 mg/kg) attenuated the amnesia in scopolamine-treated rats, but hardly affected that in nucleus basalis magnocellularis-lesioned or aged rats. In radial arm maze tasks, behavioral indices of spatial memory, such as first correct choices and number of errors, were impaired by an injection of scopolamine (0.5 mg/kg) or by lesions of the medial septum or fimbria-fornix. FR121196 ameliorated the scopolamine-induced memory deficit with a bell-shaped dose-response curve, whereas methamphetamine had the opposite effect. These two drugs had little effect on memory deficits brought about by medial septum or fimbria-fornix lesioning, whereas physostigmine ameliorated these deficits in scopolamine-treated and medial septum-lesioned rats, but not in fimbria-fornix-lesioned rats. Behavioral studies using Animex demonstrated that FR121196, in contrast with methamphetamine, does not increase locomotor activities in rats up to a dose of 10 mg/kg. These results are discussed in relation to the cholinergic and dopaminergic mechanisms of memory.     

Effects of nitric oxide synthase inhibitors 1‐(2‐trifluoromethylphenyl) – imidazole (TRIM) and 7‐nitroindazole (7‐NI) on learning and memory in mice

Nitric oxide (NO) plays an important role in hippocampal long‐term potentiation (LTP), which is involved in memory processes. This led to the hypothesis that nitric oxide synthase (NOS) inhibitors will have disturbing effects on learning and memory. The aim of our study was to investigate the effects of the new selective neuronal and inducible NOS inhibitor 1‐ (2‐trifluoromethylphenyl) imidazole (TRIM) (10–50 mg/kg) on learning and memory and compare it to the nonselective NOS inhibitor 7‐NI (15–45 mg/kg) using different behavioral tests in Swiss mice, thus clarifying the role of neuronal NOS (nNOS) and endothelial NOS (eNOS) in cognitive processes. TRIM had no specific effect on either learning or memory parameters, while 7‐NI (30 mg/kg) disturbed spatial memory in the probe trial of the Morris water maze test, which was performed on the last day of the test. No differences between TRIM and the control groups were observed, while 7‐NI (30 and 45 mg/kg) significantly disturbed memory in the novel object recognition test. In the social transmission of food preference test, both TRIM (50 mg/kg) and 7‐NI (45 mg/kg) impaired hippocampal olfactory memory, but the total food consumption was also significantly decreased at these doses. In the passive avoidance test, TRIM did not disturb the performance, while memory impairment was observed, even with lower doses of 7‐NI. All of these results suggest that TRIM has no clear effect on cognitive impairment compared to 7‐NI and that inhibition of both nNOS and eNOS are necessary for the deterioration of memory processes.     

Staurosporine facilitates recovery from the basal forebrain-lesion-induced impairment of learning and deficit of cholinergic neuron in rats

Alzheimer's disease is characterized by the loss of cholinergic neurons in the nucleus basalis of Meynert and by a primary loss of memory function. Since staurosporine has been reported to induce differentiation in human neuroblastoma cells in vitro, we studied the effects of staurosporine on the amnesia induced by basal forebrain-lesion in rats. Staurosporine (0.05 and 0.1 mg/kg intraperitoneal) attenuated the impaired performance of water maze and passive avoidance tasks, even though the drug administration began 2 weeks after the lesion. Moreover, staurosporine (0.1 mg/kg) partially reversed the decrease of choline acetyltransferase activity in the fronto-parietal cortex induced by basal forebrain-lesion. These results suggest that staurosporine attenuates impairment of learning through reversal of damage to cholinergic neurons induced by basal forebrain-lesion. This evidence indicates that neurotrophic factor-like substances may be used in novel therapeutic approaches to Alzheimer's disease.     

A comparative study of cyproheptadine and DL carnitine on psychomotor performance and memory in healthy volunteers

This study was performed in order to investigate the extent and severity of cyproheptadine effects on psychomotor performance, mood and memory functions and to compare them to the effects of DL carnitine, another appetite stimulant. Twelve healthy volunteers received 2 doses (at 800 am and 1200 am) of 6 mg cyproheptadine, 1600 mg DL carnitine and placebo on separate days at a weekly intervals. The study followed a double-blind, latin-square design. Assessment of dependent variables was performed 1 h after the first and 1 h and 5 h after the second administration of the drug. On each of these occasions, the following measurements were performed: choice reaction time (CRT), critical flicker fusion (CFF), digit symbol substitution test (DSST), short-term memory (paired words association test), long-term memory (picture test) and 100 mm visual analogue scales of subjective ratings (VAS). Cyproheptadine significantly impaired objective measures (CFF) and subjective ratings both at 1 h and 5 h after the second dosage. Compared with cyproheptadine, DL carnitine induced a slight improvement in psychomotor performance as assessed by CRT. None of the drugs had any effect on memory and on appetite at the doses studied. In conclusion, cyproheptadine at usual doses had a sedative effect, the intensity and duration of which implied a certain risk in performing daytime functions eg when driving, or manipulating machines. DL carnitine had no effect on vigilance.     

Spiro[imidazo[1,2-a]pyridine-3,2-indan]-2(3H)-one (ZSET1446/ST101) treatment rescues olfactory bulbectomy-induced memory impairment by activating Ca2+/calmodulin kinase II and protein kinase C in mouse hippocampus

Olfactory bulbectomy (OBX) in mice elicits impaired memory and cognitive functions. Here, we found that chronic oral administration of spiro[imidazo[1,2-a]pyridine-3,2-indan]-2(3H)-one (ZSET1446/ST101) (0.1-1 mg/kg/day), a novel cognitive enhancer, significantly improved memory deficits as assessed by Y-maze and novel object recognition tasks in OBX mice. Immunostaining of cholinergic neurons in the medial septum by using an anti-choline acetyltransferase antibody indicated that chronic ZSET1446 treatment did not rescue cholinergic neurons. However, chronic treatment significantly restored OBX-induced decreases both in calcium/calmodulin-dependent protein kinase II (CaMKII) and protein kinase C (PKC) phosphorylation without improving decreased extracellular signal-regulated kinase phosphorylation in the hippocampal CA1 region. Consistent with enhanced CaMKII and PKC phosphorylation, ZSET1446 treatment improved glutamate receptor 1 (Ser-831) phosphorylation in the hippocampal CA1 region. ZSET1446 treatment also significantly rescued impaired long-term potentiation (LTP) in the hippocampal CA1 region of OBX mice. Taken together, the cognition-enhancing effect of ZSET1446 is probably mediated in part by stimulation of CaMKII and PKC activities, which in turn rescue impaired hippocampal LTP in OBX mice.     

Influence of the stress hormone cortisol on fear conditioning in humans: evidence for sex differences in the response of the prefrontal cortex

The stress hormone cortisol is known to influence declarative memory and associative learning. In animals, stress has often been reported to have opposing effects on memory and learning in males and females. In humans, the effects of cortisol have mainly been studied at the behavioral level. The aim of the present experiment was to characterize the effects of a single cortisol dose (30 mg) on the hemodynamic correlates of fear conditioning. In a double-blind group comparison study subjects (17 females and 17 males) received 30 mg cortisol or placebo orally before participating in a discriminative fear conditioning paradigm. Results revealed that cortisol impaired electrodermal signs of learning (the first interval response) in males, while no conditioned SCRs emerged for the females independent of treatment. fMRI results showed that cortisol reduced activity for the CS+ > CS- comparison in the anterior cingulate, the lateral orbitofrontal cortex and the medial prefrontal cortex in males. Opposite findings (increase in these regions under cortisol) were detected in females. In addition, cortisol reduced the habituation in the CS+ > CS- contrast in the dorsolateral prefrontal cortex independent of sex. Finally, cortisol also modified the response to the electric shock (the UCS) by enhancing the activity of the anterior as well as the posterior cingulate. In sum, these findings demonstrate that in humans cortisol mostly influences prefrontal brain activation during fear conditioning and that these effects appear to be modulated by sex.     

Neuroprotective effects of Caralluma tuberculata on ameliorating cognitive impairment in a d-galactose-induced mouse model

Cognitive deficiency and oxidative stress have been well documented in aging disorders including Alzheimer’s disease. The aim of this study was to investigate the therapeutic efficacy of Caralluma tuberculata methanolic extract (CTME) on cognitive impairment in mice induced with d-galactose. In this study we assessed the therapeutic efficacy of CTME on cognitive impairment in mice induced with d-galactose by conduction of behavioral and cognitive performance tests. In order to explore the possible role of CTME against d-galactose-induced oxidative damages, various biochemical indicators were assessed. Chronic administration of d-galactose (150 mg/kg d, s.c.) for 7 weeks significantly impaired cognitive performance (in step-through passive, active avoidance test, Hole-Board test, Novel object recognition task and Morris water maze) and oxidative defense as compared to the control group. The results revealed that CTME treatment for two weeks (100, 200 and 300 mg/kg p.o) significantly ameliorated cognitive performance and oxidative defense. All groups of CTME enhanced the learning and memory ability in step-through passive, active avoidance test, Hole-Board test Novel object recognition task and Morris water maze. Furthermore, high and middle level of CTME (300 and 200 mg/kg p.o) significantly increased Total antioxidative capacity (T-AOC), Glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) activity, neprilysin (NEP), and β-site AβPP cleaving enzyme 1 (BACE1) expression while Nitric Oxide (NO), Nitric Oxide Synthase (NOS) activity and Malondialdehyde (MDA) concentration, and the level of Aβ1-42 and presenilin 1 (PS1) were decreased. The present study showed that CTME have a significant relieving effect on learning, memory and spontaneous activities in d-galactose-induced mice model, and ameliorates cognitive impairment and biochemical dysfunction in mice.     

栀子粗提物对拟痴呆模型鼠学习记忆功能障碍的影响

目的观察中药栀子粗提物对Aβ_25-35致痴呆小鼠模型及鹅膏蕈氨酸(IBO)致大鼠记忆获得障碍模型的影响。方法采用Aβ_25-35脑室注射致痴呆小鼠模型及前脑基底核注射IBO致大鼠记忆获得障碍模型,通过Morris水迷宫实验和避暗实验,观察栀子粗提物低、中、高3个剂量组(12-5、25、50 mg/kg)对模型鼠学习记忆功能的影响。阳性药采用多奈派齐(0-75 mg/kg)。结果栀子粗提物3个剂量均可提高Aβ_25-35致痴呆小鼠的Morris水迷宫空间学习记忆能力(P<0-05),中剂量对IBO致记忆获得障碍大鼠水迷宫空间学习记忆能力有明显改善作用(P<0-01);各给药组大鼠受到避暗箱内电击的潜伏期均有所延长,3 min内受到电击的次数均有所减少。结论栀子粗提物有改善拟痴呆模型鼠学习记忆功能的作用。     

Brahmi rasayana improves learning and memory in mice

Cure of cognitive disorders such as amnesia, attention deficit and Alzheimer's disease is still a nightmare in the field of medicine. Nootropic agents such as piracetam, aniracetam and choline esterase inhibitors like Donepezil are being used to improve memory, mood and behavior, but the resulting side effects associated with these agents have made their use limited. The present study was undertaken to assess the potential of Brahmi rasayana (BR) as a memory enhancer. BR (100 and 200 mg kg(-1) p.o.) was administered for eight successive days to both young and aged mice. Elevated plus maze and passive-avoidance paradigm were employed to evaluate learning and memory parameters. Scopolamine (0.4 mg kg(-1) i.p.) was used to induce amnesia in mice. The effect of BR on whole brain AChE activity was also assessed. Piracetam (200 mg kg(-1) i.p.) was used as a standard nootropic agent. BR significantly improved learning and memory in young mice and reversed the amnesia induced by both scopolamine (0.4 mg kg(-1) i.p.) and natural aging. BR significantly decreased whole brain acetyl cholinesterase activity. BR might prove to be a useful memory restorative agent in the treatment of dementia seen in elderly.     

Behavioral and neurochemical changes in rats dosed repeatedly with diisopropylfluorophosphate

Behavioral effects of organophosphates (OPs) typically decrease with repeated exposure, despite persistence of OP-induced inhibition of acetylcholinesterase (AChE) and downregulation of muscarinic acetylcholine (ACh) receptors. To characterize this tolerance phenomenon, rats were trained to perform an appetitive operant task which allowed daily quantification of working memory (accuracy of delayed matching-to-position), reference memory (accuracy of visual discrimination) and motor function (choice response latencies and inter-response times during delay). Daily s.c. injections of 0.2 mg/kg of diisopropylfluorophosphate (DFP) caused no visible cholinergic signs, did not affect body weight or visual discrimination, but progressively impaired matching accuracy and lengthened response latencies and interresponse times. These effects recovered in seven of eight treated rats after termination of DFP treatment. Resumption of daily DFP at 0.1 mg/kg caused smaller impairments of both matching accuracy and response latency. After 21 injections of 0.2 mg/kg/day of DFP, rats were subsensitive to the hypothermia induced by acute oxotremorine (0.2 mg/kg i.p.), as expected after OP-induced downregulation of muscarinic ACh receptors. Evidence for supersensitivity to scopolamine (0.03 and 0.056 mg/kg i.p.) in DFP-treated rats was mixed, with additive effects predominating on both the cognitive and motor aspects of the task. After 18 days of 0.1 mg/kg of DFP, AChE was inhibited 50 to 75% and muscarinic ACh receptor density was reduced 15 to 20% in hippocampus and frontal cortex. Progressive declines in AChE activity in hippocampus and frontal cortex across 15 daily doses with DFP at 0.1 and 0.2 mg/kg were observed in other rats; quinuclidinyl benzilate binding was significantly reduced in hippocampus after 15 doses at both levels of DFP. These results indicate that animals showing a definitive sign of tolerance to OP administration (subsensitivity to a cholinergic agonist) were also functionally impaired on both the mnemonic and motoric demands of a working memory task. The nature of this impairment suggests further that it results from compensatory changes in the central nervous system, e.g., muscarinic receptor downregulation, considered to produce "tolerance" to OPs in exposed animals.     

B lymphocyte memory: role of stromal cell complement and FcgammaRIIB receptors

To dissect the influence of CD21/CD35 and FcgammaRIIB in antigen retention and humoral memory, we used an adoptive transfer model in which antigen-primed B and T lymphocytes were given to sublethally irradiated wild-type mice or mice deficient in CD21/CD35 (Cr2(-/-)) or FcgammaRIIB receptors (FcgammaRIIB(-/-)). Cr2(-/-) chimeras showed impaired memory as characterized by a decrease in antibody titer, reduced frequency of antibody secreting cells, an absence of affinity maturation, and significantly reduced recall response. The impaired memory in Cr2(-/-) chimeras corresponded with the reduced frequency of antigen-specific memory B cells. Interestingly, FcgammaRIIB(-/-) chimeras showed a differential phenotype with impaired splenic but normal bone marrow responses. These data suggest that CD21/CD35 on stroma, including follicular dendritic cells, is critical to the maintenance of long-term B lymphocyte memory.     

Herpesvirus entry mediator (TNFRSF14) regulates the persistence of T helper memory cell populations

Memory T helper cells (Th cells) play an important role in host defense against pathogens but also contribute to the pathogenesis of inflammatory disorders. We found that a soluble decoy lymphotoxin β receptor (LT-βR)-Fc, which can block tumor necrosis factor (TNF)-related ligands LIGHT (TNFSF14) and LT-αβ binding to the herpesvirus entry mediator (HVEM) and the LT-βR, inhibited the accumulation of memory Th2 cells after antigen encounter and correspondingly reduced inflammatory responses in vivo. Showing that this was a function of the receptor for LIGHT, antigen-specific memory CD4 T cells deficient in HVEM were also unable to persist, despite having a normal immediate response to recall antigen. HVEM(-/-) memory Th2 cells displayed reduced activity of PKB (protein kinase B; Akt), and constitutively active Akt rescued their survival and restored strong inflammation after antigen rechallenge. This was not restricted to Th2 memory cells as HVEM-deficient Th1 memory cells were also impaired in surviving after encounter with recall antigen. Furthermore, the absence of LIGHT on T cells recapitulated the defect seen with the absence of HVEM, suggesting that activated T cells communicate through LIGHT-HVEM interactions. Collectively, our results demonstrate a critical role of HVEM signals in the persistence of large pools of memory CD4 T cells.     

Neuronal correlates of reduced memory performance in overweight subjects

There is growing evidence that excessive body weight correlates with impaired cognitive performance like executive function, attention and memory. In our study, we applied a visual working memory task to quantify associations between body weight and executive function. In total, 34 lean (BMI 22±2.1 kg/m(2)) and 34 obese (BMI 30.4±3.2 kg/m(2)) subjects were included. Magnetic brain activity and behavioral responses were recorded during a one-back visual memory task with food and non-food pictures, which were matched for color, size and complexity. Behavioral responses (reaction time and accuracy) were reduced in obese subjects independent of the stimulus category. Neuronal activity at the source level showed a positive correlation between the right dorsolateral prefrontal cortex (DLPFC) activity and BMI only for the food category. In addition, a negative correlation between BMI and neuronal activity was observed in the occipital area for both categories. Therefore we conclude that increased body weight is associated with reduced task performance and specific neuronal changes. This altered activity is probably related to executive function as well as encoding and retrieval of information.     

Acute effects of alcohol on neural correlates of episodic memory encoding

Although it is well established that alcohol impairs episodic memory encoding, it is unknown how this occurs on a cerebral level. We scanned intoxicated and sober individuals with functional magnetic resonance imaging (fMRI) while they encoded various materials that were recalled the following day. Alcohol impaired memory for object pairs and face-name pairs, but not for words and phrase-word pairs. Impaired performance was associated with reduced bilateral prefrontal activation and non-specific activation of the parahippocampal gyrus. These results suggest that alcohol impairs episodic memory by interfering with activity of regions involved in encoding, and further indicate which regions are critical for human memory.     

Risk factors for coronary artery disease: a study comparing hypercholesterolaemia and hypertriglyceridaemia in angiographically characterized patients

Fifty-two male patients undergoing coronary angiography were allocated to four groups each consisting of 13 subjects: group I had normal coronary arteries and patients in groups II-IV exhibited coronary artery disease. In group II, plasma cholesterol was below 250 mg dl-1 and triglycerides below 160 mg dl-1; in group III, cholesterol was above 270 mg dl-1 and triglycerides under 160 mg dl-1; and in group IV, cholesterol was under 270 mg dl-1 and triglycerides above 180 mg dl-1. The hypertriglyceridaemic group IV had the highest coronary score. In addition, it had lowest lipoprotein lipase activity, lowest HDL-cholesterol and lowest high-density lipoproteins-2 (HDL-2) levels, suggesting that this type of hypertriglyceridaemia is caused--at least in part--by lipoprotein lipase deficiency with impaired removal of the triglyceride-rich lipoproteins and increased catabolism of HDL-2. Our findings point towards a type of hypertriglyceridaemia strongly associated with coronary artery disease which should therefore be treated accordingly.     

Aripiprazole: a review of its pharmacology and clinical use

Atypical antipsychotics generally have a lower propensity for extrapyramidal side-effects (EPSE), hyperprolactinaemia and tardive dyskinesia than that associated with typical antipsychotics but may still produce troublesome side-effects, such as weight gain, cardiac rhythm changes and impaired glucose tolerance. Aripiprazole is a new atypical antipsychotic with a unique receptor binding profile that combines partial agonist activity at D2 and 5HT1A receptors with potent antagonism at 5HT2A receptors. Clinical studies in acute schizophrenic relapse, chronic schizophrenia and acute mania show it is robustly more effective than placebo. Once-daily aripiprazole 15-30 mg is as effective as haloperidol 10 mg/day and risperidone 6 mg/day in short-term treatment of schizophrenia and more effective than haloperidol 7-10 mg/day in maintenance of response in chronic schizophrenia. Aripiprazole appears to be well tolerated, with most studies suggesting a frequency of adverse effects similar to placebo. Aripiprazole seems not to cause significant EPSE, hyperprolactinaemia, excessive weight gain or cardiac rhythm disturbance. Limited data suggest that aripiprazole is not associated with impaired glucose tolerance.     

Exploring mechanism of pioglitazone-induced memory restorative effect in experimental dementia

The present study was undertaken to investigate possible mechanism of pioglitazone-induced beneficial effect in memory deficits associated with experimental dementia. Dementia was induced in Swiss albino mice by administration of streptozotocin (STZ; 3 mg/kg administered intracerebroventricularly on 1st & 3rd day). Morris Water-Maze test was employed to assess learning and memory of the animals. Brain acetylcholinesterase (AChE) activity was measured by Ell Mann's method. Brain thiobarbituric acid reactive species (TBARS) levels and reduced glutathione (GSH) levels were measured by Ohokawa's and Beutler's method respectively to assess total oxidative stress. Blood glucose level was also measured. Streptozotocin (STZ) produced a significant decrease in water-maze performance of mice hence reflecting loss of learning and memory. Pioglitazone (20 mg/kg p.o. daily for 14 days) successfully attenuated STZ-induced memory deficits, without any significant per se effect on blood glucose levels. Higher levels of brain AChE activity, TBARS and lower levels of GSH were observed in STZ treated animals, which were significantly attenuated by pioglitazone. Further, the noted beneficial effect of pioglitazone on STZ-induced dementia was significantly abolished by pre-treatment of nitric oxide (NO) synthase inhibitor l -NAME (3 mg/kg i.p.) manifested in the terms of decrease in water-maze performance and increase in brain AChE activity as well as oxidative stress. It is concluded that anti-dementic effect of pioglitazone may involve central cholinergic, oxidative and NO pathways.     

Predictors of the Use of Memory Improvement Strategies by Older Adults

This study examined the ability of depression, health, and memory self-efficacy scores to predict the use of internal and external memory strategies by cognitively impaired and cognitively intact older adults. There were no differences between the groups on memory self-efficacy scores and on the extent of their use of the external memory strategy of place. The cognitively intact group used strategies to aid memory more often than did the cognitively impaired group and used more external than internal memory strategies. The cognitively intact group used the internal strategies of elaboration and rehearsal more often than the other group and were less likely to expend effort than the other group. Memory self-efficacy scores were the sole predictor of use of external memory aids by the cognitively intact group, and age was the sole predictor of use of external memory aids by the cognitively impaired group. No variable was able to predict the use of internal memory strategies by either group.     

The novel alpha7 nicotinic acetylcholine receptor agonist N-[(3R)-1-azabicyclo[2.2.2]oct-3-yl]-7-[2-(methoxy)phenyl]-1-benzofuran-2-carboxamide improves working and recognition memory in rodents

The relative contribution of alpha4beta2, alpha7 and other nicotinic acetylcholine receptor (nAChR) subtypes to the memory enhancing versus the addictive effects of nicotine is the subject of ongoing debate. In the present study, we characterized the pharmacological and behavioral properties of the alpha7 nAChR agonist N-[(3R)-1-azabicyclo[2.2.2]oct-3-yl]-7-[2-(methoxy)phenyl]-1-benzofuran-2-carboxamide (ABBF). ABBF bound to alpha7 nAChR in rat brain membranes (Ki=62 nM) and to recombinant human 5-hydroxytryptamine (5-HT)3 receptors (Ki=60 nM). ABBF was a potent agonist at the recombinant rat and human alpha7 nAChR expressed in Xenopus oocytes, but it did not show agonist activity at other nAChR subtypes. ABBF acted as an antagonist of the 5-HT3 receptor and alpha3beta4, alpha4beta2, and muscle nAChRs (at higher concentrations). ABBF improved social recognition memory in rats (0.3-1 mg/kg p.o.). This improvement was blocked by intracerebroventricular administration of the alpha7 nAChR antagonist methyllycaconitine at 10 microg, indicating that it is mediated by alpha7 nAChR agonism. In addition, ABBF improved working memory of aged rats in a water maze repeated acquisition paradigm (1 mg/kg p.o.) and object recognition memory in mice (0.3-1 mg/kg p.o.). Rats trained to discriminate nicotine (0.4 mg/kg s.c.) from vehicle did not generalize to ABBF (0.3-30 mg/kg p.o.), suggesting that the nicotine cue is not mediated by the alpha7 nAChR and that selective alpha7 nAChR agonists may not share the abuse liability of nicotine. Our results support the hypothesis that alpha7 nAChR agonists may provide a novel therapeutic strategy for the treatment of cognitive deficits with low abuse potential.