Vocal imitation in blindfolded zebra finches (<Emphasis Type="Italic">Taeniopygia guttata</Emphasis>) is facilitated in the presence of a non-singing conspecific female

Song acquisition in young male zebra finches, Taeniopygia guttata, is viewed as a learning process by imitation from a visible conspecific male acting as a song tutor. The role played by non-singing conspecific females in this process has been poorly documented. The influence of social contact on the song learning of blindfolded young males was investigated in both female-raised and pair-raised birds. Pupils with both eyes occluded from about 35 to 65 days post-hatch, the sensitive phase for song learning, copied significantly more from an adult male sharing their cage when tutored in the presence of a female sibling than in her absence. Interestingly, the effect was more pronounced in female-raised birds compared to pair-raised birds. I conclude that physical contact in the absence of visual cues is sufficient for song imitation to occur. The results demonstrate an instance of social stimulation by non-singing females in the song acquisition of male songbirds.     

Neural organisation in the first optic ganglion of the nocturnal bee <Emphasis Type="Italic">Megalopta genalis</Emphasis>

Each neural unit (cartridge) in the first optic ganglion (lamina) of the nocturnal bee Megalopta genalis contains nine receptor cell axons (6 short and 3 long visual fibres), and four different types of first-order interneurons, also known as L-fibres (L1 to L4) or lamina monopolar cells. The short visual fibres terminate within the lamina as three different types (svf 1, 2, 3). The three long visual fibres pass through the lamina without forming characteristic branching patterns and terminate in the second optic ganglion, the medulla. The lateral branching pattern of svf 2 into adjacent cartridges is unique for hymenopterans. In addition, all four types of L-fibres show dorso-ventrally arranged, wide, lateral branching in this nocturnal bee. This is in contrast to the diurnal bees Apis mellifera and Lasioglossum leucozonium, where only two out of four L-fibre types (L2 and L4) reach neighbouring cartridges. In M. genalis, L1 forms two sub-types, viz. L1-a and L1-b; L1-b in particular has the potential to contact several neighbouring cartridges. L2 and L4 in the nocturnal bee are similar to L2 and L4 in the diurnal bees but have dorso-ventral arborisations that are twice as wide. A new type of laterally spreading L3 has been discovered in the nocturnal bee. The extensive neural branching pattern of L-fibres in M. genalis indicates a potential role for these neurons in the spatial summation of photons from large groups of ommatidia. This specific adaptation in the nocturnal bee could significantly improve reliability of vision in dim light. B.G. is grateful for travel awards from the Royal Physiographic Society, the Per Westlings Fond, the Foundation of Dagny and Eilert Ekvall and the Royal Swedish Academy of Sciences. E.J.W. acknowledges the receipt of a Smithsonian Short-Term Research Fellowship and thanks the Swedish Research Council, the Crafoord Foundation, the Wenner–Gren Foundation and the Royal Physiographic Society of Lund for their ongoing support. W.T.W. was supported by general research funds from the Smithonian Tropical Research Institute     

Tectal responses to potassium loads and subsequent visual stimuli in the toad, Bufo bufo

Calling male toads were tested behaviourally for their prey catching responses to wormlike stimuli and assigned to groups of non-hungry and hungry depending on their prey catching motivation before being prepared for visual unit, massed unit and slow potential shift (SPS) recording from the optic tectum. Control recordings to visual stimuli were made before recording the effects of application of isotonic solutions containing concentrations of 0-41 mM K(+). Application of solution was followed by presentation of the visual stimulus while the solution still bathed the tectum. The best tectal responses were made to large square visual stimuli in the non-hungry toads, perhaps because recordings were made in the breeding season. Responses of the tectum to solution addition were significant in the concentration range of 7-17 mM K(+). Hungry toads showed an earlier, smaller response than non-hungry (sexually motivated) animals. When the visual stimulus was presented, there were unit and massed unit responses at all bathing solution concentrations, which were larger in non-hungry animals. These experiments revealed that toads motivated to feed respond earlier than non-hungry toads to application of artificial CSF to the tectum, though non-hungry toads responded best to the subsequent visual stimulus.     

Key enzymes of the retinoid (visual) cycle in vertebrate retina

A major goal in vision research over the past few decades has been to understand the molecular details of retinoid processing within the retinoid (visual) cycle. This includes the consequences of side reactions that result from delayed all-trans-retinal clearance and condensation with phospholipids that characterize a variety of serious retinal diseases. Knowledge of the basic retinoid biochemistry involved in these diseases is essential for development of effective therapeutics. Photoisomerization of the 11-cis-retinal chromophore of rhodopsin triggers a complex set of metabolic transformations collectively termed phototransduction that ultimately lead to light perception. Continuity of vision depends on continuous conversion of all-trans-retinal back to the 11-cis-retinal isomer. This process takes place in a series of reactions known as the retinoid cycle, which occur in photoreceptor and RPE cells. All-trans-retinal, the initial substrate of this cycle, is a chemically reactive aldehyde that can form toxic conjugates with proteins and lipids. Therefore, much experimental effort has been devoted to elucidate molecular mechanisms of the retinoid cycle and all-trans-retinal-mediated retinal degeneration, resulting in delineation of many key steps involved in regenerating 11-cis-retinal. Three particularly important reactions are catalyzed by enzymes broadly classified as acyltransferases, short-chain dehydrogenases/reductases and carotenoid/retinoid isomerases/oxygenases. This article is part of a Special Issue entitled: Retinoid and Lipid Metabolism.     

阴道B 超引导下无痛可视人工流产术临床分析

目的:探讨阴道B超引导下可视人工流产术的应用价值。方法:观察组725例在阴道B超引导下进行无痛人工流产术,对照组481例按传统方法行无痛人流术,分别观察两组的手术时间、出血量及术后并发症等指标。结果:观察组较对照组平均手术时间缩短(P<0.05),平均术中出血量明显减少(P<0.01),并发症少。结论:阴道B型超声引导下进行人工流产术手术效果良好,与传统人工流产术比较更为安全有效,值得临床推广应用。     

Dynamic characteristics of multisensory facilitation and inhibition

Multimodal integration, which mainly refers to multisensory facilitation and multisensory inhibition, is the process of merging multisensory information in the human brain. However, the neural mechanisms underlying the dynamic characteristics of multimodal integration are not fully understood. The objective of this study is to investigate the basic mechanisms of multimodal integration by assessing the intermodal influences of vision, audition, and somatosensory sensations (the influence of multisensory background events to the target event). We used a timed target detection task, and measured both behavioral and electroencephalographic responses to visual target events (green solid circle), auditory target events (2 kHz pure tone) and somatosensory target events (1.5 ± 0.1 mA square wave pulse) from 20 normal participants. There were significant differences in both behavior performance and ERP components when comparing the unimodal target stimuli with multimodal (bimodal and trimodal) target stimuli for all target groups. Significant correlation among reaction time and P3 latency was observed across all target conditions. The perceptual processing of auditory target events (A) was inhibited by the background events, while the perceptual processing of somatosensory target events (S) was facilitated by the background events. In contrast, the perceptual processing of visual target events (V) remained impervious to multisensory background events.     

Enabling High Grayscale Resolution Displays and Accurate Response Time Measurements on Conventional Computers

Display systems based on conventional computer graphics cards are capable of generating images with 8-bit gray level resolution. However, most experiments in vision research require displays with more than 12 bits of luminance resolution. Several solutions are available. Bit++ ¹ and DataPixx ² use the Digital Visual Interface (DVI) output from graphics cards and high resolution (14 or 16-bit) digital-to-analog converters to drive analog display devices. The VideoSwitcher ³ described here combines analog video signals from the red and blue channels of graphics cards with different weights using a passive resister network ⁴ and an active circuit to deliver identical video signals to the three channels of color monitors. The method provides an inexpensive way to enable high-resolution monochromatic displays using conventional graphics cards and analog monitors. It can also provide trigger signals that can be used to mark stimulus onsets, making it easy to synchronize visual displays with physiological recordings or response time measurements.Although computer keyboards and mice are frequently used in measuring response times (RT), the accuracy of these measurements is quite low. The RTbox is a specialized hardware and software solution for accurate RT measurements. Connected to the host computer through a USB connection, the driver of the RTbox is compatible with all conventional operating systems. It uses a microprocessor and high-resolution clock to record the identities and timing of button events, which are buffered until the host computer retrieves them. The recorded button events are not affected by potential timing uncertainties or biases associated with data transmission and processing in the host computer. The asynchronous storage greatly simplifies the design of user programs. Several methods are available to synchronize the clocks of the RTbox and the host computer. The RTbox can also receive external triggers and be used to measure RT with respect to external events. Both VideoSwitcher and RTbox are available for users to purchase. The relevant information and many demonstration programs can be found at http://lobes.usc.edu/.     

A comparison of the estrous behavior of Holstein-Friesian cows when cubicle-housed and at pasture

This study compared estrous behavior of dairy cows kept in cubicle housing and fed a total mixed ration diet (HOUSED treatment) with that of cows kept at pasture with concentrate supplementation (PASTURE treatment). Behavior was compared both in the 48 h around standing estrus and during the standing estrus period. The 23 spring-calving Holstein-Friesians in each treatment were observed directly three times per day for nine weeks. The occurrence of nine selected behaviors associated with estrus was recorded during 20 min observation sessions. Twelve standing estrus events from each treatment were selected for analysis of the frequency of these nine behaviours over the 48 h around standing estrus. Milk progesterone profiles were used to confirm the dates of standing estrus events. Attempting to mount other cows, sniffing the anogenital region of other cows, resting the chin on other cows, receiving chin rests and head-to-head butts all showed significant changes in frequency in the 48 h around standing estrus in both treatments, reaching a peak during standing estrus (P ≤ 0.05). Mounting other cows increased significantly in the PASTURE treatment around standing estrus (P < 0.001), but not in the HOUSED treatment. The frequency of ano-genital sniffs received by the animals in the PASTURE treatment also increased significantly around standing estrus (P < 0.01) but not in the HOUSED treatment. When the animals were in standing estrus there was a significantly higher frequency of standing to be mounted in PASTURE than in HOUSED cows (median (q1, q3) PASTURE = 2.5 (1.0, 3.0), HOUSED = 0.0 (0.0, 1.0)) (P < 0.01), but no difference in the frequency of the other eight sexual behaviors recorded. HOUSED cows did not exhibit the same increase in mounting during the standing estrus period as PASTURE cows and received fewer mounts in observation sessions during standing estrus. These results have implications for the use of estrus detection systems that rely solely on mounting behavior in cubicle-housed dairy cows.     

Weaponry, color, and contest success in the jumping spider Lyssomanes viridis

Weaponry and color badges are commonly theorized to function as visual signals of aggressiveness or fighting ability. However, few studies have supported a signaling function of weaponry, and the role of color in invertebrate competitive interactions remains virtually unexplored. Jumping spiders (Salticidae) make excellent invertebrate models for studying weaponry and color because males of many species are colorful and possess exaggerated chelicerae, which are used as weapons in escalated contests. To determine whether color or weaponry might function as visual signals in male-male competitions, we investigated relationships between contest success, cheliceral length, and red coloration in Lyssomanes viridis. Males having longer chelicerae than their opponents were significantly more likely to win (p=0.0008). Males who won, despite being smaller than their opponents, had significantly less red chelicerae than their opponents (p=0.01). Male and female cheliceral length, as well as foreleg length, correlated tightly with body size. Cheliceral and foreleg length showed significantly stronger positive allometry in males than in females. We conclude that male chelicerae and forelegs are under strong positive selection for their use in physical fights and/or as visual signals of fighting ability.     

Role of the apolipoprotein E and catechol-O-methyltransferase genes in prospective and retrospective memory traits

Human memory is a complex neurocognitive process. By combining psychological and molecular genetics expertise, we examined the APOE ε4 allele, a known risk factor for Alzheimer's disease, and the COMT Val 158 polymorphism, previously implicated in schizophrenia, for association with lowered memory functioning in healthy adults. To assess memory type we used a range of memory tests of both retrospective and prospective memory. Genotypes were determined using RFLP analysis and compared with mean memory scores using univariate ANOVAs. Despite a modest sample size (n=197), our study found a significant effect of the APOE ε4 polymorphism in prospective memory. Supporting our hypothesis, a significant difference was demonstrated between genotype groups for means of the Comprehensive Assessment of Prospective Memory total score (p=0.036; ε4 alleles=1.99; all other alleles=1.86). In addition, we demonstrate a significant interactive effect between the APOE ε4 and COMT polymorphisms in semantic memory. This is the first study to investigate both APOE and COMT genotypes in relation to memory in non-pathological adults and provides important information regarding the effect of genetic determinants on human memory.