正常大鼠视网膜电图振荡电位的频谱特性分析

背景暗适应视网膜电图（ERG）的振荡电位（OPs）在多种视网膜疾病的视功能评价中发挥重要作用,但其波形的确切起源尚未完全明确。OPs波的时域和频域分析及其影响因素的研究对进一步研究OPs的发生和起源具有重要意义。目的观察正常大鼠的暗适应ERGOPs与刺激光强度和动物年龄的关系。方法选择出生后21、25、32、35、37、46、60及90d的RCS—rdy^＋-P^＋大鼠各3只,采用RETI—scan记录系统进行闪光视网膜电图（F—ERG）OPs波记录,记录电极为环形角膜电极,参考电极为不锈钢针状电极,刺激强度分别为-20、-10、-5、0、5dB,通过Matlab提取OPs成分,分析其频谱特性。结果上述各种刺激强度下不同年龄组大鼠OPs的最大能量振幅值对应的频率值（即主频）范围为80～120Hz。随着刺激光强度的增加,开始出现高频（200—250Hz）成分,对应的振幅值随着刺激光强度的增加而增加;低频成分,即主频随着刺激光强度的增加其对应振幅值出现先升高后下降的趋势;当刺激光强度达到0dB时,低频成分出现双峰现象。25日龄大鼠OPs主频振幅最小,60日龄大鼠OPs主频振幅最大;25日龄大鼠OPs主频的带宽最窄,60日龄大鼠OPs主频的带宽最宽。结论大鼠ERG的OPs频域特性分析说明,刺激光强度对大鼠OPs振幅产生正向的影响,而大鼠的年龄主要影响OPs的主频分布。     

正常食蟹猴不同适应时间视网膜电图的 变化

目的：研究明/暗适应时间对正常成年食蟹猴闪光视网膜电图（ERG）结果的影响。方法：实验研究。 选取3只成年食蟹猴,分别于暗适应20、40、60 min后用国际临床视觉电生理会标准参数刺激,常 规程序记录暗适应ERG,在暗适应40 min后,分别明适应1、5、10 min记录明适应ERG。采用单因 素方差分析比较各时间段振幅与潜伏期变化。结果：不同暗适应时间,a、b波和震荡电位OPs的潜 伏期差异均无统计学意义（F=0.052,P=0.949）,暗适应时间小于40 min时,a、b波和OPs的振幅随暗 适应时间增加而显著增大（F=50.800,P<0.001）;暗适应40 min时,振幅达到最大,且不再随暗适应 时间增加而增大（F=0.016,P=0.899）。明适应a、b波的潜伏期同样不受明适应时间的影响（F=0.980, P=0.381）,a、b波的振幅在明适应5 min后达到最大（F=4.789,P=0.036）且随时间延长趋于平稳 （F=0.135,P=0.717）。结论：在一定时间内,明/暗适应时间对食蟹猴闪光ERG结果影响较大,故对 食蟹猴暗适应ERG记录的时间不宜少于40 min,而明适应ERG在5 min后即可记录。     

干性年龄相关性黄斑变性的局部视网膜电流图研究

目的研究干性年龄相关性黄斑变性(Age—related macular degeneration AMD)患者的局部视网膜电流图(LERG)反应，探讨黄斑区视网膜功能损害的程度。方法对33例(60眼)干性AMD患者和18例(30眼)正常入应用稳态的闪烁光LERG和全视野暗适应闪光ERG检测。测量振幅和峰时。结果干性AMD患者LERG平均振幅显著下降，平均峰时明显延长，与正常对照组比较有显著差异。干性AMD患者全视野暗适应闪光ERG的a波、b波振幅和峰时与正常对照组无显著差异。结论干性AMD患者行LERG检测可直接了解其黄斑区视网膜外层功能，评估其病变程度有一定的临床意义。     

正常成年SD大鼠明视闪光视网膜电图特征

目的:探讨正常成年SD大鼠的明视视网膜电图(Electroretinogram,ERG)特征.方法:选取正常9～12周SD大鼠60只,使用罗兰视觉电生理仪记录大鼠右眼的明视闪光ERG.使用SPSS统计分析a波、b波和明视负波反应(Photopic negative response,PhNR)的隐含期和振幅.比较雄性和雌性SD大鼠明视ERG特征.结果:每只SD大鼠均能记录到稳定的a波、b波和PhNR,其中a波的隐含期和PhNR的隐含期及振幅均符合正态分布,而其余指标均不符合正态分布.PhNR的隐含期为124.6±8.5ms,其变异系数最小(0.07).PhNR的振幅为(11.3±4.2)μV,变异系数为0.37.雄性和雌性SD大鼠明视ERG的各反应波之间无显著差异.结论:在正常成年SD大鼠,明视闪光ERG是一项客观评价大鼠明视状态下视网膜功能的手段,PhNR可以作为一项稳定的评价内层视网膜功能的指标.     

干性年龄相关黄斑变性的局部视网膜电流图研究

目的研究干性年龄相关性黄斑变性(AMD)患者的局部视网膜电流图(LERG)反应。探讨黄斑区视网膜功能损害的程度。方法对33例(60眼)干性AMD患者和18例(30眼)正常人应用稳态的闪烁光LERG和全视野暗适应闪光ERG检测，测量振幅和峰时。结果干性AMD患者LERG平均振幅显著下降，平均峰时明显延长，与正常对照组比较有显著差异。干性AMD患者全视野暗适应闪光ERG的a波、b波振幅和峰时与正常对照组无显著差异。结论干性AMD患者行LERG检测可直接了解其黄斑区视网膜外层功能．评估其病变程度有一定的临床意义。     

兔视网膜下非活动视觉假体载片植入对ERG的影响

目的 用视网膜电图(ERG)探究视网膜下非活动视觉假体载片植入对视网膜功能的影响.方法 24只新西兰白兔,随机分为手术组和伪手术组(各12只兔).记录各组术前及术后7、15、30、60d(每时间点3只兔)ERG b波振幅.统计各组ERG的a波和b波振幅数值,进行t检验和单因素方差分析.结果 各组间及手术组、伪手术组时间点间ERG a波振幅未见明显差异.手术组术后ERG b波振幅较术前正常对照组有不同程度升高(P=0.038),手术组与伪手术组间及伪手术组与术前正常对照组间差异无统计学意义(P=0.649和P=0.369),手术组和伪手术组时间点间差异无统计学意义.结论 手术组视网膜下非活动视觉假体载片植入后ERG b波振幅有不同程度的升高,提示载片植入后在一定时间范围内可能保护视网膜的功能.     

高血糖对实验性糖尿病大鼠视网膜电图的影响

目的观察糖尿病大鼠ERG和OPs的变化情况,探讨糖尿病对大鼠FERG和OPs的影响。方法将100只大鼠分为正常组10只和糖尿病组90只。糖尿病组用STZ造模,6个月后将符合条件的大鼠纳入观察组。检测6、9个月时大鼠ERG和OPs的表现。结果糖尿病大鼠视网膜电图a波、b波、OPs振幅有下降趋势,峰潜时延长,与对照组大鼠相比有差异(P<0.01);9个月时糖尿病大鼠a波、b波、OPs振幅降低,峰潜时延迟,与6个月时比较有显著差异(P<0.01或0.05)。结论高血糖可使糖尿病大鼠ERG和OPs振幅下降,峰潜时延长;且随病程的延长其影响逐渐增强。     

利用锥体细胞失功能大鼠和先天性静止性夜盲大鼠对视锥与视杆通路振荡电位的分离研究

背景 振荡电位(OPs)是评估视网膜缺血缺氧性疾病视网膜功能变化的重要工具,利用视网膜退行性病变动物模型对视锥、视杆通路起源的OPs特点进行研究非常重要. 目的 在两种自发性视网膜退行性病变模型大鼠中分离视锥、视杆通路,对比分析视杆、视锥通路起源的OPs波的特点. 方法 采用雄性SD大鼠、锥体细胞失功能(RCD)大鼠、先天性静止性夜盲(CSNB)大鼠各6只,以RETI-scan视觉生理记录系统分别在暗适应(12h)和明适应(10 min)条件下,用不同强度的刺激光(-35、-25、-15、-5、0、5 db)进行刺激,记录各组大鼠的闪光视网膜电图(FERG),通过Matlab 7.0的Butterworth滤波提取OPs,采用快速傅里叶变换(FFT)对所得OPs进行频谱分析.结果 暗适应条件下SD大鼠和RCD大鼠的ERG均可见a波和b波,但CSNB大鼠b波阙如;明适应条件下,SD大鼠和CSNB大鼠可见b波,但RCD大鼠各波阙如.暗适应较高刺激光强度下,SD大鼠和RCD大鼠均有低频(主频)和高频(次频)两个明显的频峰,分别为75 ～ 110 Hz、90～120 Hz和90～ 120 Hz、110 ～ 135 Hz;不同刺激光强度下,CSNB大鼠只有一个频峰,为70～100 Hz.而明适应不同刺激光强度下,SD大鼠和CSNB大鼠均只有一个频峰,分别为75～95 Hz和70～85 Hz.明适应条件下与SD大鼠比较,CSNB大鼠b波隐含时延长,b波振幅明显下降,差异均有统计学意义(P＜0.05);暗适应条件下,RCD大鼠b波隐含时和振幅与SD大鼠比较,差异无统计学意义(P＞0.05);与SD大鼠比较,RCD和CSNB大鼠OPs波振幅下降,隐含时延长,差异均有统计学意义(P＜0.05);明适应条件下不同刺激光强度下CSNB大鼠OPs波的隐含时明显长于SD大鼠,振幅明显低于SD大鼠,差异均有统计学意义(P＜0.05). 结论 视锥、视杆通路起源的OPs有不同特性,自发性视网膜退行性改变大鼠的视杆OPs有两个频峰,正常情况下,视杆通路对OPs的贡献比视锥通路大.     

不同年龄阶段成年人闪光视网膜电图参数及变异性分析

目的：探讨不同年龄阶段成年人闪光视网膜电图参数及其变异性。

方法：将30例60眼健康体检者按年龄分为2组：20～30岁组(15例30眼)和40～50岁组(15例30眼),按ISCEV标准行全视野闪光ERG检查,比较两组间各参数及变异系数。

结果：两组相比各波隐含期均延长,振幅均下降,尤其在暗适应3.0、明适应3.0及震荡电位振幅表现出有统计学意义(P<0.05); 各项观察指标中隐含期的变异系数最小,振幅次之,而震荡电位振幅变异系数最大。

结论：40～50岁年龄组与20～30岁年龄组相比,ERG各波隐含期延长,振幅下降,各波隐含期变异系数小。     

碘酸钠诱导大鼠视网膜退行性改变的作用机制

目的 探讨碘酸钠(NaIO₃)诱导大鼠视网膜退行性改变的作用机制。方法 取雄性SD大鼠20只，随机分为对照组和模型组。采用30 mg·kg^-1 NaIO₃尾静脉注射，建立大鼠干性年龄相关性黄斑变性病变模型。继续饲养21 d,检测大鼠视网膜电图(ERG),观察大鼠视网膜组织病理学变化，检测大鼠视网膜组织超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性和丙二醛(MDA)含量，采用液相色谱-质谱联用分析差异蛋白情况。结果 ERG检测结果显示，模型组大鼠暗适应0.01ERG、暗适应3.0ERG、暗适应3.0振荡电位以及明适应3.0ERG和明适应3.0闪烁光反应b波振幅分别比对照组降低79.98%、81.64%、76.08%、61.68%、57.25%,差异均有统计学意义(均为P<0.05)。与对照组相比，模型组大鼠视网膜组织细胞层数减少，尤其是外核层、内核层结构紊乱，呈现明显的波浪形变化。与对照组相比，模型组大鼠视网膜组织SOD和CAT活性分别下降12.51%和14.08%,MDA含量增加57.96%,差异均有统计学意义...     

Correlation of electroretinographic and fluorescein angiographic findings in unilateral central retinal vein obstruction

Background: In central retinal vein obstruction (CRVO), electroretinogram (ERG) abnormalities and extensive retinal capillary dropout (CD) in the fluorescein angiogram (FA) are good indicators of retinal ischemia. We retrospectively studied patients with unilateral CRVO and compared the ERG and FA results Methods: Single white flash ERG, photopic ERG, scotopic ERG and flicker ERG were recordered in 30 cases of unilateral CRVO. We analyzed the correlation between the ERG results and the presence/absence of extensive CD Results: The ERG b/a-wave amplitude ratios, photopic and scotopic b-wave amplitudes, and flicker amplitudes were significantly smaller (P<0.05) in eyes with extensive CD (n=12, 40%), than in eyes without (n=18, 60%). When the photopic or scotopic b-wave amplitudes were normal or supernormal, extensive CD on FA was absent in all eyes. When the b/a-wave ratios were 1.0 or when the b-wave amplitudes with white flash or flicker amplitudes were normal or supernormal, extensive CD was present in less than 32% of eyes Conclusion: These results suggest that the ERG results, especially the b/awave amplitude ratio, are significantly correlated with the presence/absence of CD on FA in CRVO.     

Electroretinographic abnormalities in a rat glaucoma model with chronic elevated intraocular pressure

The purpose of this study was to determine the ability of electroretinographic (ERG) measurements to document progression of the retinopathy in a rat glaucoma model. Thirty four rats with a chronic intraocular pressure (IOP) elevation induced in one eye by cautery of three episcleral/extra-orbital veins were studied in four separate groups. ERGs were recorded sequentially in Group A rats (n = 12) at baseline, and after approximately 20, 40 and 60 days of high IOP, and in three additional groups of rats (n = 6 or 10 per group) after approximately 58, 30 and 175 days of high IOP, respectively. Scotopic ERG parameters recorded simultaneously from both eyes in Group A rats were: a- and b-wave amplitudes, implicit times, oscillatory potential amplitudes (OPs) determined at three different light-flash intensities, and the light-adapted (photopic) ERG b-wave amplitude. In the other groups of rats, only scotopic ERG a-wave, b-wave and OP amplitudes were measured.In Group A rats that were followed sequentially, all the ERG parameters recorded with attenuated stimuli showed significant time-dependent changes in glaucomatous eyes relative to their contralateral normal eyes, with OPs showing the earliest significant difference after only 3 weeks of high IOP. When different groups of unilateral glaucomatous rats were compared beyond 8 weeks of elevated IOP only the OPs showed a continued decrease with time and good discrimination between glaucoma and normal eyes. Over a 25 week period of high IOP the scotopic OPs measured with attenuated light stimuli declined at the rate of approximately 1.5% per week and provided the best ERG measure to monitor progression of retinal pathophysiology in the vein-occlusion rat glaucoma model.     

Comparison of electroretinographic responses between two different age groups of adult Dark Agouti rats

AIM: To describe and compare the differences in electroretinographic responses between two different age groups of adult Dark Agouti (DA) rats and to better understand the effect of age on retinal histology and function.METHODS: The electroretinographic responses of two different age groups of adult DA rats were compared. Animals were divided into younger adult DA rats 10-12wk (n=8) and older adult DA rats 17-19wk (n=8). Full field electroretinography (ERG) was recorded simultaneously from both eyes after dark adaption and light adaption and parameters including the positive scotopic threshold response (pSTR), negative scotopic threshold response (nSTR), scotopic a-wave, b-wave, photopic a-wave, b-wave and photopic negative response (PhNR) were compared between groups.RESULTS: The older adult rats displayed lower stimulation thresholds of the STRs (pSTR and nSTR) and higher amplitudes of pSTR, scotopic a-wave and b-wave, photopic b-wave and PhNR amplitudes, with shorter implicit times. Photopic a-wave amplitudes were however higher in the younger adult rats.CONCLUSION:In summary, for the rod system, photoreceptor, bipolar cell and RGC activity was enhanced in the older adult rats. For the cone system, RGC and bipolar cell activity was enhanced, while photoreceptor activity was depressed in the older adult rats. Such age-related selective modification of retinal cell function needs to be considered when conducting ophthalmic research in adult rats.     

Structural and functional maturation of the retina of the albino Hartley guinea pig

PURPOSE: Altricial animals, such as rats and mice, are born with their eyes closed, compared to precocial animals, such as guinea pigs and humans, which have their eyes opened at birth. The purpose of this study was to investigate if the retina of guinea pigs (precocial animal) is subjected to a postnatal maturation process similar to that previously reported for rodents. METHODS: Photopic and scotopic electroretinograms (ERG) and retinal histology were obtained from albino guinea pigs aged P1 to P75. RESULTS: Photopic ERG responses reached maximal amplitudes at P5 (a-and b-waves), that is 5 days (b-wave) to 10 days (a-wave) earlier than scotopic responses. However, the postnatal gain in b-wave amplitude was significantly (P < 0.05) more important for the cone (73.38 +/- 4.4%) signal than for the rod (15.23 +/- 3.96%), suggesting that the rod function is more mature at birth. Similarly, the short latency photopic oscillatory potential (ie: OP2) reached its maximal value 5 days (P10) earlier than its scotopic equivalent (P15), while the long latency OPs (ie: OP3, OP4), reached their maximal values nearly 20 days sooner in scotopic condition. Finally retinal histology revealed a thinning of the retina with age, the latter being most pronounced at the level of the ganglion cell layer (GCL). CONCLUSION: Our results thus confirm that despite its relative maturity at birth (compared to rodents), the retina of newborn albino guinea pigs undergoes significant postnatal maturation modifying its structure as well as its function, albeit not as extensive as that previously documented for altricial animals.     

影响视网膜脱离患者视网膜功能的因素

目的:评价视网膜脱离患者年龄、病程、视网膜脱离面积、黄斑脱离情况等因素对视网膜功能的影响。方法:将孔源性视网膜脱离(retinal detachment,RD)188例189眼的患者年龄、病程、视网膜脱离面积、黄斑脱离情况、视力与视网膜脱离眼的fERG和mfERG各指标进行相关分析。结果:影响RD眼fERG和mfERG的主要因素是脱离面积、黄斑脱离和视力。以|γ|>0.4,且P≤0.05判定为有相关性。脱离面积与明视和暗适应最大反应ERG a、b波幅值,30Hz闪烁光幅值,OPs波数和幅值负相关;与mfERG象限野P1波幅值密度、幅值负相关。相关系数最高者为fERG暗适应最大反应b波幅值(γ=-0.704)。黄斑脱离与明视和暗适应最大反应ERG b波幅值,30Hz闪烁光ERG幅值负相关;与mfERG环形野环1的P1波幅值密度、幅值负相关,与mfERG象限野P1波幅值密度负相关,相关系数最高者为mfERG环形野环1的P1波幅值(γ=-0.584)。视力与明视和暗适应最大反应a、b波幅值,30Hz闪烁光幅值,OPs子波数和幅值正相关;与mfERG环形野环1的P1波幅值密度、幅值正相关,相关系数最高者为30Hz闪烁光ERG幅值(γ=0.597)。RD眼的fERG异常率最高者为暗适应最大反应ERG b波幅值,异常率为71.3%,视网膜脱离象限野mfERG异常率最高者为P1波幅值,异常率为85.3%。结论:影响RD患者视网膜功能的重要因素是脱离面积和黄斑脱离情况。RD眼对视网膜功能异常反应的mfERG对视网膜功能异常反应的敏感性高于fERG。     

Partial preservation of rod and cone ERG function following subretinal injection of ARPE-19 cells in RCS rats

We quantified rod- and cone-related electroretinogram (ERG) responses following subretinal injections of the human-derived retinal pigment epithelial (hRPE) cell line ARPE-19 at age P23 to prevent progressive photoreceptor loss in the Royal College of Surgeons (RCS) rat. Culture medium-injected eyes served as sham controls. At P60, in comparison with sham-injected eyes, all recordings from hRPE-injected eyes showed preserved scotopic a- and b-waves, oscillatory potentials, double-flash-derived rod b-waves and photopic cone b-waves, and flicker critical fusion frequencies and amplitudes. Although the actual preservation did not exceed 10% of a-wave and 20% of b-wave amplitude values in non-dystrophic RCS and deteriorated rapidly by P90, rod- and cone-related ERG parameters were still recordable up to P120 unlike the virtually unresponsive sham-injected eyes.     

Predominant loss of the photopic negative response in central retinal artery occlusion

PURPOSE: To determine how the photopic negative response (PhNR) is affected in central retinal artery occlusion (CRAO). DESIGN: Observational case series. METHODS: Seven patients with unilateral CRAO were included. Full-field scotopic and photopic electroretinograms (ERGs) including the PhNR were recorded. Each ERG amplitude in the affected eye was expressed as a percentage of amplitude of the corresponding wave in the unaffected eye. RESULTS: Mean of the PhNR amplitude was reduced to 12.3 +/- 11.7% of that of unaffected eyes whereas the cone b-wave amplitude was attenuated to only 73.4 +/- 30.4%. This reduction of the PhNR amplitude was more significant than that of other waves including the rod b-wave, maximum a-wave and b-wave, cone a-wave and b-wave, and 30 Hz flicker ERG (P <.005). CONCLUSIONS: The PhNR was severely affected in CRAO despite relative preservation of the cone b-wave, implicating massive loss of ganglion cells and their axons.     

Effects of hypoxemia on the a- and b-waves of the electroretinogram in the cat retina

PURPOSE: Slow components of the electroretinogram (ERG) are sensitive to even mild hypoxemia (60 < P(a)O(2) < 100 mm Hg) in the cat eye. However, the electrical responses of the inner retina remain unchanged until P(a)O(2) is below 40 mm Hg. In this study, the effects of hypoxemia on photoreceptors, on which both slow ERG components and inner retinal activity depend, were examined by recording the a-wave of the ERG. METHODS: The ERG of dark-adapted, anesthetized cats was recorded between an Ag-AgCl electrode in the vitreous humor and a reference electrode near the eye. Responses to bright flashes of diffuse white light were recorded at 3-minute intervals during hypoxemic episodes lasting 15 minutes to 2 hours. RESULTS: The cat a-wave was well described by the Lamb and Pugh a-wave model during normoxia and hypoxemia. During mild hypoxemia (P(a)O(2) of 50-60 mm Hg), small changes in a-wave amplitude were detected but did not become greater during severe hypoxemia. The mean decrease in the a-wave amplitude during severe hypoxemia (P(a)O(2) of 20-30 mm Hg) was 8.9% from the mean amplitude during air breathing. The effects of hypoxemia were more severe on the b-wave amplitude. The mean decrease in the b-wave was 35% at P(a)O(2) of 20-30 mm Hg. CONCLUSIONS: The a-wave is more resistant to severe hypoxemia than the b-wave. This implies that photoreceptor transduction works almost normally during hypoxemia and that failure of inner retinal PO(2) regulation causes the decrease in the b-wave. Previously observed changes in the amplitudes of slow ERG components during hypoxemia may result from changes in the ionic environment, rather than a failure of photoreceptor energy metabolism.     

环孢霉素A微球兔眼玻璃体内注射的毒性研究

目的 研究一种新型的嵌段聚酯高分子化合物（ε－已丙酯－D，L－丙交酯嵌段共聚物）将环孢霉素A（CsA）包封制备成微球，兔眼玻璃体注射后对视网膜和视功能的毒性。方法 采用10只有色兔，玻璃体注射前行间接检眼镜眼底检查及眼电生理检查（ERG）均正常。含有750μgCsA的5mg微球以注射用生理盐水混悬，在间接检眼镜观察下注射到每只兔的左眼玻璃体腔中部，同样剂量的空白微球注射到右眼对照眼玻璃体中央。在注射后的不同时间点进行ERG检查。处死动物，摘取眼球对视网膜行组织学检查，并检查眼底至8周。结果 注射后1－2周时，平均的b波明显被抑制（P＜0．05），最大的暗适应ERG抑制出现在第1周。实验眼与对照眼的b波振幅比率为49．5％。ERG值在第4周基本恢复正常。b波的潜伏值在暗适应条件下为正常。a波振幅值和潜伏值在暗适应条件下实验眼与对照眼没有明显差异。组织学检查显示实验眼与对照眼的视网膜在第6周时没有明显改变。结论 玻璃体内注射可降解微球可以安全地将CsA传递至兔眼的后节段。     

Origin of electroretinogram amplitude growth during light adaptation in pigmented rats

We assessed the growth of the rat photopic electroretinogram (ERG) during light adaptation and the mechanisms underlying this process. Full field ERG responses were recorded from anesthetized adult Brown-Norway rats at each minute for 20 min of light adaptation (backgrounds: 1.8, 2.1, 2.4 log scotopic cd m(-2)). The rat photopic b-wave amplitude increased with duration of light adaptation and its width at 33% maximal amplitude narrowed (by approximately 40 ms). These effects peaked 12-15 min after background onset. The narrowing of the b-wave reflected steepening of the b-wave recovery phase, with little change in the rising phase. OP amplitudes grew in proportion to the b-wave. Inhibition of inner retinal responses using TTX resulted in a greater relative growth of b-wave and OP amplitude compared with fellow control eyes, and delayed the change in recovery phase by approximately 5 min. Inhibition of all ionotropic glutamate receptors with CNQX/D-AP7 delayed both rising and recovery phases equally (approximately 12 ms) without altering b-wave width or the time course of adaptation changes. These outcomes suggest that inner retinal light responses are not directly responsible for b-wave amplitude growth, but may contribute to the change in its recovery phase during adaptation. A TTX-sensitive mechanism may help to hasten this process. The cone a-wave was isolated using PDA/L-AP4 or CNQX/L-AP4. A-wave amplitude (35 ms after stimulus onset) also increased with time during light adaptation and reached a maximum (130 +/- 29% above baseline) 12-15 min after background onset. B-wave amplitude growth in fellow control eyes closely followed the course and relative magnitude of cone a-wave amplitude growth. Hence, the increase of the cone response during light adaptation is sufficient to explain b-wave amplitude growth.