Reflection of space characteristics of an acoustic signal in the neuronal activity of the caudate nucleus

In chronic experiment, responses of single neurons of the caudate nucleus (CN) to spatial characteristics of acoustic signal have been investigated in dogs. It is shown that 92% of neurons of the caudate nucleus' head responding to sound stimulation asymmetrically react to contra- and ipsilateral monoaural, with a greater efficacy of a contralateral stimulation. For 50% of the CN neurons simultaneous sound inputs appear more effective in comparison with contralateral stimulation. 77% of the caudate neurons responding to sound have shown sensitivity to change of the value and sign of the interaural delay.     

The influence of environmental change on the behaviour of sheltered dogs

The majority of sheltered dogs are overlooked for purchase because they are considered undesirable by potential buyers. Many factors may determine a dog's appeal, although of interest here are the dog's behaviour and cage environment which can influence its desirability. People prefer dogs which are at the front rather than the back of the cage, quiet as opposed to barking, and alert rather than non-alert. Potential buyers also prefer dogs which are held in complex as opposed to barren environments. This study examined the behaviour of sheltered dogs in response to environmental change, to determine whether it influenced dog behaviour in ways that could be perceived as desirable to potential dog buyers, and/or had any effect upon the incidence of dogs purchased from the shelter. One hundred and twenty dogs sheltered by the Ulster Society for the Prevention of Cruelty to Animals were studied over a 4-h period. The dogs' position in the cage, vocalisation, and activity were investigated in response to increased human social stimulation, moving the dog's bed to the front of the cage, or suspending a toy from the front of the dog's cage. Social stimulation resulted in dogs spending more time at the front of the enclosure, more time standing, and slightly more time barking. Moving the bed to the front of the cage encouraged dogs to this position, but did not influence activity or vocalisation. Suspending a toy at the front of the pen exerted no effect on dog behaviour, although its presence in the pen may help to promote more positive perceptions of dog desirability. The incidence of dogs purchased from the rescue shelter increased whenever the dogs' cages were fitted with a bed at the front of the pen, whenever the dogs were subjected to increased regular human contact, and whenever a toy was placed at the front of the enclosure. Findings highlight the important role that cage environment can play in shaping the behaviour of sheltered dogs and influencing whether or not an animal will become purchased.     

Neurophysiologic analysis of the critical period of delay of a reinforcing stimulus in the dog

At interval of less than 100 ms between indifferent sound and unconditioned electrocutaneous stimulation, classical defensive conditioned reflex is not elaborated in dogs, in full correspondence with literature data. But intracortical temporary connection is established; this fact is shown by electrographic phenomena, the most specific and demonstrative among them is "conditioned evoked potential". The absence of behavioural (peripheral) and presence of electrographic (central) manifestations allow to assume that for the formation of the conditioned reflex of full value the involvement is necessary of additional activational (motivational) mechanisms, connected with reticular and (or) limbic subcortical structures which do not react to the conditioned stimulus at time deficit in conditions of microdelay.     

Discrimination of signals simulating movement of a sound source by dogs after ablation of the auditory cortex

The ability to perceive a moving sound image at dichotic stimulation was studied by means of avoidance technique for decorticated (AI, AII, Ep) dogs. The bilateral ablation disturbed the temporal cue discrimination of the direction of movement. But the animals retained the ability to localize the moving signal using delta I-cue.     

声波刺激对菊花愈伤组织膜脂物理状态和膜脂代谢的影响

以蔗糖梯度法纯化的菊花 (Dendranthemamorifolium (Ramat.)Tzvel.)愈伤组织质膜微囊为材料 ,研究了声波刺激下质膜膜脂代谢和物理状态的变化。结果表明 ,一定强度 (10 0dB)和频率 (10 0 0Hz)的声波刺激使质膜磷酸二脂含量和二苯己三烯 (DPH)荧光偏振值降低 ,质膜光散射值、MC5 40荧光强度和磷酸单脂含量增加。表明一定强度和频率的声波刺激使质膜变疏松 ,膜的流动性增加 ,膜表面电荷密度和疏水性降低 ,膜脂合成代谢增加 ,分解代谢减弱。由此可见 ,膜脂物理状态和膜脂代谢对声波刺激极为敏感。     

Effect of activating the putamen on alimentary conditioned reflexes in dogs

The influence was studied of the near-threshold high- and low-frequency stimulation of the putamen on achievement of alimentary conditioned reflexes in dogs. Both low- and high-frequency activation of the examined structure significantly changes the parameters of intermediate secretion, of the salivary conditioned reflexes, without influencing unconditioned ones. Unilateral stimulation disturbs the achievement of positive and inhibitory conditioned reflexes to a greater extent than bilateral one. Difference between the effects of low- and high-frequency stimulation has been revealed.     

Structure of the osseous callus formed under electric stimulation. An experimental histological study

The study tried to evidence histologically, histometrically and mechanically the comparative qualities of the osseous callus experimentally formed in dogs and rabbits under the influence of an electric stimulation. The materials were decalcified or polished, and the collagen network and the Haversian systems analysed in the callus. The tearing strength in kg-power on the surface unity of the osseous tissue was measured using the EDZ 20 apparatus. The results indicated that the osseous tissue formed under electric stimulation had a structure and a tearing strength similar to that of controls, and that the consolidation time of fractures is reducing.     

Modulation of lipolysis by endotoxin and indomethacin in fat cells of germfree and conventional dogs.

Germfree fat cells released significantly less FFA and glycerol under basal conditions (i.e. in the absence of hormonal stimulation) than conventional cells. The lipolytic response to norepinephrine stimulation (0.2 μg/ml) was not different in the two cell populations.$\text{E. coli}$ endotoxin increased basal lipolysis and norepinephrine stimulated (0.2 μg/ml) FFA release in adipocytes from conventional dogs, while having no consistent influence on lipolysis of adipocytes from germfree dogs. The endotoxin effect was not dose dependent (0.2–2.0 μg/0.5 ml cell suspension).Indomethacin (5.0 μg/ml) significantly increased basal FFA and glycerol release from cells of germfree origin, and FFA efflux from cells of conventional dogs. Endotoxin obviated the influence of indomethacin on basal lipolysis of germfree cells.Endotoxin by itself did not alter cAMP concentrations in adipocytes from germfree dogs. The combination of indomethacin and endotoxin, however, significantly increased intracellular cyclic nucleotide concentrations.Compared to conventional fat cells, germfree fat cells are characterized by significantly reduced basal lipolysis, lack of a consistent lipolytic response to endotoxin stimulation and dissociation of the lipolytic response and cAMP levels by the combined influence of endotoxin and indomethacin.     

Influence of hypophysectomy on the lifespan of the corpus luteum in the cyclic dog

Five dogs were hypophysectomized on Day 4 and 9 on Day 18. Prolactin and LH stimulation tests showed that hypophysectomy was complete in 6 dogs only. In these dogs, the progesterone concentration was measured in the peripheral blood; it decreased sharply immediately after surgery. It regained normal values in 3 of the 4 dogs hypophysectomized on Day 4, and remained low in the 2 dogs hypophysectomized on Day 18. This indicates that, in the dog, luteal function is autonomous during a certain period. The luteal period of the 3 dogs hypophysectomized on Day 4 was shorter than that of control animals, although the time of onset of luteal regression appeared to be similar. This indicates that pituitary luteotrophic support is required during the second part of the oestrous cycle of the dog.     

The effect of electrostimulation of the caudate nucleus and somatosensory cortex on defensive instrumental reactions in dogs]

It has been shown that the effect of stimulation of the caudate nucleus head in the contralateral hemisphere differs at different stages of achievement of a defensive instrumental habit in dogs. Stimulation preceding the action of the conditioned signal or delivered simultaneously with the beginning of the latter did not change the criteria for the achievement of successive programs of the instrumental defensive reaction. Stimulation of the same areas in the last phase of the instrumental response, as a rule, lead to the cessation of instrumental movement. A conclusion has been drawn that in a defensive situation the inhibitory influence of the caudate nucleus on instrumental behaviour of intact dogs is not so sharply expressed as in experiments with alimentary reinforcement. In dogs with a preliminary ablation of the CI and CII cortical zones of the contralateral hemisphere, stimulation of the caudate nucleus head was attended with a sharp drop in every criterion of the instrumental defensive reactions.     

Effects of acoustic stimuli on neuronal activity in the auditory cortex of the rat

Spontaneous activity of cortical neurons exhibits alternative fluctuations of membrane potential consisting of phased depolarization called "up-state" and persistent hyperpolarization called "down-state" during slow wave sleep and anesthesia. Here, we examined the effects of sound stimuli (noise bursts) on neuronal activity by intracellular recording in vivo from the rat auditory cortex (AC). Noise bursts increased the average time in the up-state by 0.81+/-0.65 s (range, 0.27-1.74 s) related to a 10 s recording duration. The rise times of the spontaneous up-events averaged 69.41+/-18.04 ms (range, 40.10-119.21 ms), while those of the sound-evoked up-events were significantly shorter (p<0.001) averaging only 22.54+/-8.81 ms (range, 9.31-45.74 ms). Sound stimulation did not influence ongoing spontaneous up-events. Our data suggest that a sound stimulus does not interfere with ongoing spontaneous neuronal activity in auditory cortex but can evoke new depolarizations in addition to the spontaneous ones.     

Fore-Aft Ground Force Adaptations to Induced Forelimb Lameness in Walking and Trotting Dogs

Animals alter their locomotor mechanics to adapt to a loss of limb function. To better understand their compensatory mechanisms, this study evaluated the changes in the fore-aft ground forces to forelimb lameness and tested the hypothesis that dogs unload the affected limb by producing a nose-up pitching moment via the exertion of a net-propulsive force when the lame limb is on the ground. Seven healthy Beagles walked and trotted at steady speed on an instrumented treadmill while horizontal force data were collected before and after a moderate lameness was induced. Peak, mean and summed braking and propulsive forces as well as the duration each force was exerted and the time to reach maximum force were evaluated for both the sound and the lame condition. Compared with the sound condition, a net-propulsive force was produced by the lame diagonal limbs due to a reduced braking force in the affected forelimb and an increased propulsive force in the contralateral hindlimb when the dogs walked and trotted. To regain pitch stability and ensure steady speed for a given locomotor cycle, the dogs produced a net-braking force when the sound diagonal limbs were on the ground by exerting greater braking forces in both limbs during walking and additionally reducing the propulsive force in the hindlimb during trotting. Consistent with the proposed mechanism, dogs maximize their double support phases when walking. Likely associated with the fore-aft force adaptations to lameness are changes in muscle recruitment that potentially result in short- and long-term effects on the limb and trunk muscles.     

The influence of sound stimulation during hatching on the mortality of ducks

In the work the influence of the artificial sound stimulation during incubation on the speed of the Pekin duck breed hatching as well as on their mortality during that period was observed. The set eggs were hatched in four hatcheries. The eggs of the first two hatcheries (control groups Ka and Kb) were not sound stimulated. In the other two groups the set eggs were, from the very first hour of hatching, stimulated by the "knocking" sound from an electronic sound generator (experimental groups "a" and "b"). For the stimulation, the acoustic signal with intensity of 25 dB and frequency 5.68 Hz was applied. The fastest hatching process was recorded in the groups with sound stimulation. The "a" experimental group was the fastest, the ducks were hatched after 640.75+/-10.15 hours, in the "b" experimental group the ducks were hatched after 656.50+/-1.70 hours of incubation. In both sound stimulated experimental groups (a, b) the increased embryonic mortality resulted in the decrease of the percentage of hatchability--to 68.09+/-1.77% and 76.44+/-2.68%, respectively. This is statistically evident (P<0.01) when compared with the respective control groups which reached the 88.81+/-1.86% and 89.35+/-0.81% hatchability.     

低强度脉冲超声波辐照与泡沫TiC/Ti对犬节段性骨缺修复的促进作用

目的探讨低强度脉冲超声波辐照对节段性骨缺损修复效果的影响。方法将直径12 mm长20mm泡沫TiC/Ti植入6只Beagle犬的左侧胫骨节段性骨缺损区。随机分为超声组和对照组,超声组采用低强度脉冲超声波辐照（频率1.5 MHz、强度30 mW/cm2、脉冲宽度200μs、脉冲周期1 kHz、20 min/次、1次/d）,对照组为不开功率源的假辐照,术后4、8周后分别行X线检查及骨密度测定,观察及分析材料周围骨愈合情况。结果 6只beagle犬均进入结果分析。术后4周超声组骨早期成熟度优于对照组,表现在材料周围骨痂影密度增高,骨痂影由两端向中央生长;对照组仅见骨痂区密度低,还可见部分骨痂缺如。术后8周超声组新生骨痂面积优于对照组,骨干结构相对稳定;对照组骨缺损区未闭合,在骨干两侧看到少量骨痂,愈合较差。骨密度测定结果显示,4周时超声组高于对照组,两组间存在统计学差异;8周时超声组略高于对照组,但两组间没有统计学差异。结论通过联合应用低强度脉冲超声波辐照与人工骨材料修复可提高新骨形成速度及骨组织密度,缩短节段性骨缺损的骨愈合时间。     

Effects of Acoustic Context on the Perceptual Differences between Spatial Sound Stimuli

We studied the effects of the acoustic context on active and passive discrimination of moving sound signals. Different contexts were created by reversing the role of standard and deviant stimuli in the oddball blocks, while their acoustical features were kept the same. Three types of sounds were used as standard or deviant stimuli in different blocks: stationary midline noises and two (smooth and abrupt) moving sounds moving to the left or right of the midline. Auditory event-related potentials (ERPs) were recorded during passive listening (the sound stimulation ignored), and mismatch negativity potentials (MMNs) were obtained. Active discrimination of sound movements was measured by the hit rate (percent correct responses) and false alarm rate, as well as the reaction time. The influence of the stimulus context on active and passive discrimination of the moving sound stimuli was reflected in the phenomenon known as the effect of deviance direction. The hit rate and MMN amplitude were higher when the deviant moved faster than the standard. The MMN amplitude was more responsive to the velocity of sound stimuli than the hit rate and false alarm rate. The psychophysical measurements in the reversed contexts suggest that smooth and abrupt sound movements may belong to the same perceptual category (moving sounds), while the stationary stimuli form another perceptual category.     

The disinhibitory influence of the activating system when artificially excited from different points in the brain]

EEG activation can be produced by electrical stimulation of some cortical points with the same threshold current strength as by the midbrain RF and thalamic CM stimulation. Near-threshold stimulation of all these points acting simultaneously with inhibitory conditioned signals does not disturb the effector inhibition but displays an EEG difference between negative signals: the fine differentiation sound evokes considerable EEG desynchronization, while the rough one does not change the background rhythms. The same stimulation combined with a positive signal which has been made ineffective by successive inhibition or extinction, reestablishes the intensive EEG activation in response to this signal and the effector conditioned reflex. Therefore a mode-rate additional stimulation of the activating points in the cortex, RF and CM has a disinhibitory influence. When initiated in the cortex this influence may be transmitted from the cortical point to other parts of the brain along transcortical and corticofugal connections.     

音频刺激与光耦合激发蝗虫趋光响应的效应

目的：研究光声耦合和对照光激发蝗虫趋光响应试验,为蝗虫的光电诱导捕集治理及趋光增益调控激发技术提供理论基础。方法：依据蝗虫趋光机理和声频刺激激发蝗虫的响应特性,利用LED光源、声频播放设备和蝗虫行为试验装置,进行了蝗虫对光声耦合和光谱光照趋光响应的对比测定,并探讨了光声耦合对蝗虫趋光效果影响的机理。结果：（1）蝗虫光声感受器对光能和声能接受和神经处理方式的不同,光谱光照和声频耦合刺激激发蝗虫生物活性和趋光v向应的双重叠加效应,增强了蝗虫的趋光活性,强化了蝗虫的趋光行为,提高了蝗虫的趋光响应,达到了推拉驱动蝗虫趋光响应的效应;（2）在光声耦合激发蝗虫趋光响应峰值上,蝗虫对不同声刺激的敏感性参数不同;（3）蝗虫对声刺激敏感参数接受的容限性,导致光谱光照在蝗虫诱导响应行为中起主导作用,而声刺激则起驱动激发蝗虫趋光响应的增益效应。结论：光谱光照和声刺激的合理布置和组合,能够有效提高蝗虫的趋光诱导响应效果。     

Inhibitory processes in neuronal reactions of the auditory cortex in the cat undergoing dichotic stimulation

In experiments on anaesthetized cats, studies have been made of intracellular and extracellular responses of single units in the auditory cortex during dichotic stimulation simulating sound source motion. Responses of some cortical units exhibit strong dependence on the signal parameters related to spatial and directional characteristics of simulated sound source motion. Profound inhibition was invariably revealed at the beginning of sonic stimulation as well as during certain moments of its movement. The role of inhibition in formation of cortical reactions to sound source motion is discussed.     

Vestibular, vaginal and urethral relationships in spayed and intact normal dogs

The purpose of this study was to evaluate the urogenital anatomy in sound spayed and intact dogs. Fourteen intact and 12 spayed sound dogs had their lower urogenital tract evaluated with conventional vaginourethrography, computed tomography (CT) vaginourethrography and uroendoscopy under general anesthesia. Measurements for each of the three imaging modalities were made. Measurements included vaginal length, vaginal height, vaginal width, vestibule length, vestibule height, vestibule width, cingulum height, cingulum width, cingulum area, urethral length, urethral height, urethral width, angle of urethra to vestibule and angle of vagina to vestibule. Group comparisons were made between sound spayed and intact dogs. In general, most measurements were greater in intact dogs compared to spayed dogs regardless of imaging modality utilized. Group-weight interactions (P<0.01) were found on conventional vaginourethrograms (vaginal height and length and vestibule height, length and width) and CT vaginourethrograms (vaginal length, vestibule height, length and width, cingulum area, urethral width and angle of vagina to vestibule). A three-way interaction (P<0.01) for vaginal length, vaginal height and vestibule height was also identified. Vestibule length and height, cingulum height and urethral length were larger (P<0.01) with increasing dog weight and in intact dogs for both conventional and CT vaginourethrograms. No difference in vestibulovaginal ratio was observed between intact dogs and spayed dogs (P=0.0221). One of 14 intact dogs and 8 of 12 spayed dogs had vestibulovaginal ratios <0.33 on conventional vaginourethrograms. Anatomical differences in the lower urogenital tract between spayed and intact dogs emphasizes the need to establish normal reference ranges for spayed and intact dogs.     

Developmental changes in audiogenic epilepsy and myoclonus in KM rats

The reaction to a single sound stimulation (a bell) applied daily and the time of the first appearance of myoclonus were recorded in Krushinsky-Molodkina (KM) rats of different ages (30, 60, and 150-200 days). The audiogenic seizures in adult animals were of short latency and always resulted in tonic convulsions, which were stable in their patten. In contrast, in young animals (in particular, in 30-day-old rats), the seizures were less pronounced and unstable. The daily sound stimulation produced a gradual development of myoclonic seizures in young and adult rats. In old rats, the stable myoclonus appeared on the 17th day of stimulation, and in 30-day-old animals the myoclonus was recorded on the 26th day. In 60-day-old rats the myoclonus appeared for the first time on the 20th day of stimulation. It is suggested that these age differences can be explained by the btain immaturity (in particular, of neurotransmitter system) in young animals.