【CASK EFFECT】0910F阅读全方位锻炼--越障【SCI】 1-13

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【CASK EFFECT】0910G阅读能力基础自测（速度、难度、深度、越障、真题、RAM）
https://bbs.gter.net/forum.php?mod=viewthread&tid=910464&highlight

【CASK EFFECT】0910F阅读全方位锻炼--越障【SCI】汇总贴
https://bbs.gter.net/thread-982020-1-1.html

规则：0 u, r. g$ C/ d+ [4 f5 C

我每天贴出1000字左右的一篇文字7 j) N0 Q, Q- ]( V4 E

没有别的要求，只要大家坚持读完就可以

如果你能坚持一个月，你会发现自己的阅读进化了~
[注]9 K7 C8 w4 {" L
1、直接在电脑屏幕面前做，虽然GRE阅读是在纸上考，但是这个过程会遏制你做笔记，同时给你的阅读造成视觉障碍，也就是把难度训练和抗干扰训练同步结合，增加效率（初期会很累，但是既然大家想要成为高手，那么就别对自己太温柔）

Today's topic: Rapid visual learning in the rat: Effects at the 5-HT1a receptor subtype

The 5-hydroxytryptamine1a (5-HT1a) receptor agonist 8-hydroxy-2-(di-n-propylamino) tetralin(8-OH-DPAT; 0.15 mg/kg) impaired rats’ rapid visual learning on a computerized maze.This treatment also increased decision time (DT) but the learning impairment was not necessarily a side-effect of slower responding because, in this task,responses made at long DT are more accurate than those at short DT. The selective 5-HT1a receptor antagonist WAY±100635 (0.3mg/kg) was itself without effect on accuracy, but was effective in reversing effects of 8-OH-DPAT (on both accuracy and DT). Within problems (i.e., over the 40±60 rials of a single discrimination), performance was reduced by treatment with 8-OH-DPAT at all stages of learning. We conclude that this effect is mediated through the 5-HT1a receptor site (rather than through some other serotonergic receptor site or non-specific mechanism) as it was reversible by treatment with WAY±100635.Although it could still arise from behaviourally non-specific effects, the performance deficit finds its best account in terms of the psychological processes necessary to visual learning. Its reversal with WAY±100635 offers support to the hypothesis that 5-HT1a receptor antagonists could improve cognitive function, under conditions of pre-existing impairment due to overactive serotonergic inhibition, as is thought to occur in Alzheimer’s disease.

The serotonergic (5-hydroxytryptamine, 5-HT) system is implicated in normal learning and in impairments of learning due to ageing and dementia (Altman& Normile, 1988; McEntee & Crook, 1991). Thus antagonists at the 5-HT1areceptor site could provide a mechanism to increase the function of cortical pyramidal cells in Alzheimer’s disease (e.g., Bowen, Francis, Pangalos,Stephens, & Proctor, 1992; Francis, Sims, Procter, & Bowen, 1993). Such antagonists might work by blocking the tonic hyperpolarizing effects of endogenous5-HT and thus enhance glutamatergic excitation in functioning cells (Dijk, Francis,Stratmann, & Bowen, 1995). Further, in normal animals, 5-HT1a receptor agonists like 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) might similarly ``switch off ’’ cortical pyramidal neurones and result in cognitive deficits (Francis et al., 1993).

We previously found that 8-OH-DPAT impaired visual learning as measured by discriminative accuracy, independent of its effects on response time, which was used as a measure of non-specific effects (Cassaday &Gaffan, 1996). However,8-OH-DPATis now known to bind 5-HT7 receptor sites (Shen et al., 1993). To define further the relevant receptor subtypes, in the present study we tested whether 8-OH-DPAT’s effects in this task are reversible by treatment with a5-HT1a receptor antagonist. WAY±100635 is 100-fold selective for the 5-HT1a receptor site relative to its binding at other sites (Forster et al., 1995).

Although 5-HT1a receptor antagonists have been shown to block a number of 8-OH-DPAT effects (Fletcher et al., 1996), there have been relatively few clear demonstrations that 8-OH-DPAT has cognitive effects (but see Carli &Samanin, 1992), and a number of studies have highlighted the difficulty in dissociating cognitive effects from non-specific effects on performance when8-OH-DPAT is given systemically (e.g., Stanhope, McLenachan, & Dourish,1995; Warburton, Harrison, Robbins, & Everitt, 1997). Given this difficulty,there is scant evidence that cognitive effects of 8-OH-DPAT are blocked bypre-treatment with selective 5-HT1a receptor antagonists. Carli and Samanin(1992) found that 8-OH-DPAT impaired spatial learning in the water maze and went on to demonstrate that spatial impairment could be demonstrated by(intrahippocampal) 8-OH-DPAT treatment that was without effect on visual learning in the same water maze task (Carli, Luschi, Garofalo, & Samanin,1995). This dissociation suggests that the spatial impairment was not simply a consequence of non-specific deleterious effects of the 8-OH-DPAT treatment.

In the present study, we assessed the effect of systemic 8-OH-DPAT and WAY± 100635 using exactly the same paradigm and apparatus as previously (constant-negative discrimination training in a computer-controlled Y-maze, Cassaday & Gaffan, 1996), to allow direct comparison. In this procedure, rats learn a series of discrimination problems in which the stimuli are complex, wide-angle visual displays (``scenes’’)drawn from a large population. Each problem consists of a series of trials in which the rat chooses between two scenes: the constant, which is the same on every trial, and the variable, which is different on every trial. Food reward is given for choosing the variable not the constant.

We tested pigmented rats of two strains, Dark Agouti (DA) and Hooded Lister (HL). HLsare less proficient than DAs at visual learning (Aggleton, 1996; Gaffan &Eacott, 1995) so it was necessary to give them a slightly less demanding version of the task in order to maintain constant discrimination and to keep the baseline performance comparable to that of the DAs. Thus the DAs learned two new problems per session for 40 trials each (a similar procedure to that of Cassaday &Gaffan, 1996), whereas the HLs had only one new problem per session for 60 trials. We analysed to check that drug effects were consistent across the groups.

It is important to dissociate the motor side-effects of a drug such as8-OH-DPAT from its effects on learning per se. In our apparatus, accuracy of discrimination varies with decision latency, faster responses being less accurate than slower responses (Cassaday & Gaffan, 1996; Gaffan &Eacott, 1997). 8-OH-DPAT can affect response time, lengthening or shortening it at different doses, and such effects must be compensated for when assessing whether a particular dose of the drug changes choice accuracy during discrimination learning. Cassaday and Gaffan (1996) developed a method of partialling out the effects of a drug on speed of responding from its effect on discrimination.

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先评分，再看题
？恩？沙发了？我很奇怪那个加减号到底算是个什么，我记得可以当误差值的，这个里面似乎直接当标识符了……

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解决！