Connections of the cat stellate ganglion with target organs during postnatal ontogenesis

The enzyme horseradish peroxidase was administered into trachea, esophagus, heart, sternocleidomastoid muscle, and biceps of newborn, 10-, 20-day old kittens, and adult cats. The labeled neurons were located on the topical basis of the stellate ganglion. In newborn kittens, the largest cells take part in the heart innervation. In animals of other ages, the largest cells take part in innervation of the sternocleidomastoid muscle. The findings suggest that, in postnatal ontogenesis, neuronal organisation of the stellate ganglion is changing parallel to an enhancement of the neurons' size and ganglion section area.     

Activity of caudal mesenteric ganglion in relation to its impulsation (age aspect)

It has been shown in acute experiments on cats and kittens that the pre- and postganglionic nerves of the caudal mesenteric sympathetic ganglion (CMSG) are bioelectrically active from the first day of the animal's life. When the impulsation which comes to the ganglion along the afferent and preganglionic fibers is removed, the impulse activity of the post-ganglionic neurons disappears completely. In newborn kittens the level of activity of the postganglionic fibers is determined to a greater degree by the afferent impulsation of the hypogastric nerves than in adult cats. The effect of the preganglionic impulsation, especially that coming through the intramesenteric nerves, predominates in adult animals. The efferent impulsation of the hypogastric nerves in cats not older than five days disappeared after sectioning of two to three preganglionic branches of the CMSG; in six to nine and 14 to 15-day-old cats, after sectioning of four and in month old cats after sectioning of five; and in two to three month old cats after sectioning of six branches. In adult cats after the first sectioning the postganglionic impulsation frequently intensified, and after sectioning of seven branches the activity completely disappeared. Automatic activity of the ganglia was not observed, postganglionic impulsation developed and changed under the influence of the impulses coming to the ganglion.Scientific Research Institute of Childhood and Adolescent Physiology, Academy of Pedagogical Sciences USSR, Moscow. Translated from Neirofiziologiya, Vol. 3, No. 5, pp. 533–542, September–October, 1971.     

Postnatal development of respiratory and vocal responses during aversive classical conditioning in cats

Respiratory rate, respiration amplitude, and vocal responses were recorded in cats of different ages during classic conditioning. Vocal responses to the conditional stimulus (CS) appeared first in 8-week-old kittens, and became prominent at older ages. An increase in respiration rate occurred after the onset of the CS in cats of all ages. Similarly, the decrease of respiration amplitude was observed at all ages, but only in 8-week-old and older subjects did this response resemble an adult pattern. In 4-week-old kittens the response was characterized by an early and brief peak, suggesting an alpha conditional response (CR). Clear and significant discrimination between a warning and a safety signal was present in both respiratory and vocal responses after the age of 8 weeks.     

Ontogenesis of the asymmetry of transcallosal responses in the cat parietal cortex

In acute experiments on 2-24 days old immobilized kittens and adult cats, studies have been made on the development of functional interhemispheric asymmetry of homotopical transcallosal responses in the parietal cortex. It was found that the number of animals with evident asymmetry increases with age. Alongside, with respect to such characters as asymmetry coefficient, mean amplitude of components of transcallosal components and the ratio of zones of direct and inverse domination, the increase in functional interhemispheric asymmetry was observed during the second week of postnatal life of kittens, which was accompanied by the inversion of its sign; in adult cats, the decrease in the asymmetry up to its complete absence was found. The data obtained are discussed with respect to peculiarities of the development and functional properties of the associative parietal cortex in cats.     

The phenomenon of the replication of ontogenetic immaturity in adult cats caused by the cerebrospinal fluid of kittens

Studies have been made on the electrical activity of muscles in the hindlimbs in kittens and adult cats before and after injection the liquor from 10-, 21-day and 1-month kittens into the lumbar part of the spinal cord. Analysis was made of the EMG at rest and that of the evoked reactions. It was shown that EMG of adult cats after injection of kitten liquor attained the pattern typical of the donor. The data obtained indicate the presence in kitten liquor of biologically active substances which account for the level of regulatory relationships. Transfer of these substances to adult animals results in the formation of a new level of coordinations of movements which corresponds to immature organism.     

Ontogeny of the expression of some catecholamine synthesising enzymes in the female porcine preoptic area

Ontogeny of the catecholaminergic system of the preoptic area (PA) was studied in various animal species including mice, rats, cats and lower vertebrates. Until now, there has been no data about development of catecholaminergic structures in the porcine PA. To study this problem, hypothalami from six groups of animals were collected. Three groups of foetuses (70, 84 and 112 days old) and three groups of female pigs (1 day, 10 weeks and 7-8 months old) were used. Nerve structures immunoreactive for the studied substances: tyrosine hydroxylase (TH), dopamine beta-hydroxylase (DbetaH) and phenylethanoloamine-N-metylthransferase (PNMT) were observed in different periods. In PA, TH-IR (immunoreactive) structures appeared before 70th day of foetal life, DbetaH-IR between 70th and 84th day of foetal live and PNMT-IR only in 10-week old and adult animals. In the PA of 70-day old foetuses, single smooth and varicose nerve fibres immunoreactive only to TH were found. In PA of 84-day old foetuses, additionally, single nerve cell bodies immunoreactive to TH were shown and some of them also contained immunoreactivity to DbetaH. In PA of 1-day old piglets, moderate numbers of nerve fibres immunoreactive to TH and only single TH/DbetaH-IR nerve terminals were observed. TH-IR nerve cell bodies were also moderate in number and many of them contained simultaneously immunoreactivity to DbetaH. In PA of 10-week old pigs, a moderate number of immunopositive nerve fibres was observed. They contained mainly TH, but part of them stained also for TH/DbetaH. Only very few nerve fibres containing exclusively DbetaH were found. These nerve terminals were observed in a close vicinity of blood vessels. In PA, moderate numbers of TH-IR nerve cell bodies were found, some of them contained also immunoreactivity to DH but never to PNMT. Perikarya containing PNMT were TH-negative. In the PA of sexually mature sows, additional, single, large nerve cell bodies (about 35 microm in a diameter) containing TH only were found. In many cases, TH- and DbetaH-IR "basket-like" structures surrounding nerve cell bodies were seen, suggesting an influence of those fibres on the neuronal activity.     

猫视神经年龄相关的形态学变化

对4只青年猫(1-3龄)和4只老年猫(10-13龄)视神经进行形态计量比较研究。取两个年龄组的颅内相应部分视神经进行横向连续切片,H.E染色于光镜下观察其基本结构;相邻切片进行结晶紫染色显示胶质细胞;神经丝蛋白(NF)免疫染色显示视神经纤维,胶质纤维酸性蛋白(GFAP)免疫染色显示星形胶质细胞(AS),对实验结果进行统计学分析并绘制纤维直径谱。与青年猫相比,老年猫视神经外膜厚度、直径、面积均显著增加,视神经纤维的密度和数量显著下降,且以视神经中央部纤维密度下降最显著;纤维直径谱分析结果显示,青、老年猫纤维直径分布范围相似,但老年猫的峰直径及纤维平均直径比青年猫的显著减小;另外,老年猫视神经束中的星形胶质细胞明显膨大,胶质细胞密度以及星形胶质细胞占胶质细胞总数的百分比均显著增加。结果表明:在衰老过程中视神经纤维出现明显的丢失现象,纤维平均直径显著减小使其对视觉信息的传导速度减慢,这可能是导致老年个体视觉分析速度下降的重要原因;老年个体视神经束内胶质细胞活动增强可能对维持视神经纤维形态、功能或延缓视神经进一步衰老起保护作用     

Analysis of the layer distribution of transcallosal responses in the sensorimotor cortex of kittens in the 1st month of life

In experiments on 23 kittens ageing between 1-30 days, anaesthetized by barbiturate and immobilized by diplacine, studies have been made on the distribution of transcallosal responses (TCRs) along the whole diameter of the sensorimotor cortex. In order to obtain more accurate data on localization of the sources and drains of extracellular current vertical component, a method of double graphic differentiation was used. It was shown that in 1-2-day kittens TCRs have a positive oscillation form throughout all the depth of recording. During the 1st week, TCRs from the cortical surface acquired a positive-negative configuration, remaining mostly positive in deeper layers. At this ontogenetic stage, the drain of positive-negative oscillation is focused in the layer I. In 2-3-week kittens, positive-negative potentials on the surface were transformed into negative-positive responses in deep layers. The drains of this deep negative component were localized in the layers III and V-VI. On the 4th week, positive-negative TCRs on the surface changed into negative-positive potentials at various depths depending on the spatial position of the recording point. The drain of deep-laid negative component in the focus of maximum activity was found in the layer V, out of its boundaries--in the layers II-III. Ontogenetic dynamics was revealed of current drains localization of both TCRs components in the sensorimotor cortex in new-born kittens.     

Taurine in the developing cat: Uptake and release in different brain areas

Taurine is an important modulator of neuronal activity in the immature brain. In kittens, taurine deficiency causes serious dysfunction in the cerebellar and cerebral visual cortex. The processes of taurine transport in vitro were now studied for the first time in different brain areas in developing and adult cats. The uptake of taurine consisted initially of two saturable components, high- and low-affinity, in synaptosomal preparations from the developing cerebral cortex and cerebellum, but the high-affinity uptake component completely disappeared during maturation. The release of both endogenous and preloaded labeled taurine from brain slices measured in a superfusion system was severalfold stimulated with a slow onset by depolarizing K⁺ (50 mM) concentrations. K⁺ stimulation released markedly more taurine from the cerebral cortex, cerebellum and brain stem in kittens than in adult cats. The responses were largest in the cerebellum. Both uptake and release of taurine are thus highly efficient in the brain of kittens and may be of significance in view of the vulnerability of cats to taurine deficiency.     

Dissociations between the behavioral effects of LSD and tolerance development during ontogeny in cats: a novel approach to the study of tolerance mechanisms

The characteristic behavioral effects of d-lysergic acid diethylamide (LSD) in cats first appeared at approximately 25 days of age and increased rapidly in magnitude over the next 10 days. However, 25 day old kittens showed no tolerance to the repeated administration of the drug. While the behavioral response to the initial dose of LSD remained relatively constant between 35 and 112 days of age, the tolerance gradually became more pronounced throughout this time period, reaching an adult level of virtually complete tolerance at 112 days. These findings provide new insight into the nature of the relationship between the primary drug action and the development of tolerance, and suggest a new strategy for investigating the neural bases of tolerance, i.e., examining the neurochemical effects of repeated LSD administration in kittens during various stages of tolerance development.     

Substance P and neurokinin A immunoreactive nerve fibres in the developing salivary glands of the rat

The time of appearance and distribution of substance P (SP) and neurokinin A (NKA) immunoreactive nerve fibres in developing salivary glands of the rat were studied by the use of indirect immunohistochemical methods. The glands were examined at daily intervals from the 15th day in utero (i.u.) until birth, and subsequently on the 2nd, 5th, 7th, 12th, 16th and 30th postnatal day. The findings were compared to samples from adult. The first SP- and NKA-immunoreactive (IR) nerve fibres appeared on the 19th day i.u. in the parotid and submandibular glands and were abundantly distributed around developing ductal branches. In the mesenchyme around the developing ductal branches of the parotid gland the fibres appeared on the 20th day i.u. In the submandibular gland NKA-IR fibres appeared in the mesenchyme surrounding the developing ductal branches on the 19th day i.u. and SP-IR fibres on the 21st day i.u. Around blood vessels of both glands, SP- and NKA-IR fibres made their appearance only much later, on the second postnatal day. The number of SP- and NKA-IR nerve fibres in the developing salivary glands was already high on the 19th day i.u. when they were first detected. From this point up to the 16th postnatal day the glands were richly innervated by the fibres, but later the numbers slowly decreased to adult levels. The abundance of SP- and NKA-IR nerve fibres especially around the ductal branches and secretory structures in the developing salivary glands suggests a role in the functional maturation of salivary glands.     

Substance P and neurokinin A immunoreactive nerve fibres in the developing salivary glands of the rat.

The time of appearance and distribution of substance P (SP) and neurokinin A (NKA) immunoreactive nerve fibres in developing salivary glands of the rat were studied by the use of indirect immunohistochemical methods. The glands were examined at daily intervals from the 15th day in utero (i.u.) until birth, and subsequently on the 2nd, 5th, 7th, 12th, 16th and 30th postnatal day. The findings were compared to samples from adult. The first SP- and NKA-immunoreactive (IR) nerve fibres appeared on the 19th day i.u. in the parotid and submandibular glands and were abundantly distributed around developing ductal branches. In the mesenchyme around the developing ductal branches of the parotid gland the fibres appeared on the 20th day i.u. In the submandibular gland NKA-IR fibres appeared in the mesenchyme surrounding the developing ductal branches on the 19th day i.u. and SP-IR fibres on the 21st day i.u. Around blood vessels of both glands, SP- and NKA-IR fibres made their appearance only much later, on the second postnatal day. The number of SP- and NKA-IR nerve fibres in the developing salivary glands was already high on the 19th day i.u. when they were first detected. From this point up to the 16th postnatal day the glands were richly innervated by the fibres, but later the numbers slowly decreased to adult levels. The abundance of SP- and NKA-IR nerve fibres especially around the ductal branches and secretory structures in the developing salivary glands suggests a role in the functional maturation of salivary glands.     

猫腰髓白质年龄相关的形态学变化

以青年成年猫(1-3龄,2-2．5 kg)和老年猫(12龄,3-3．5kg)L6段脊髓白质为研究对象,用 神经丝蛋白(NF)免疫染色显示神经纤维,用改良的Holzer结晶紫染色显示所有胶质细胞并用成年动物Golgi 法显示其形态,用胶质纤维酸性蛋白(GFAP)免疫染色显示星形胶质细胞。光镜下对青年猫与老年猫腰髓白质 中神经纤维和胶质细胞进行形态学观察和定量研究。与青年猫相比,老年猫腰髓白质中的神经纤维密度显著下 降(P相似文献   

Functional magnetic resonance imaging during hypotension in the developing animal.

Hypotension in adult animals recruits brain sites extending from cerebellar cortex to the midbrain and forebrain, suggesting a range of motor and endocrine reactions to maintain perfusion. We hypothesized that comparable neural actions during development rely more extensively on localized medullary processes. We used functional MRI to assess neural responses during sodium nitroprusside challenges in 14 isoflurane-anesthetized kittens, aged 14-25 days, and seven adult cats. Baseline arterial pressure increased with age in kittens, and basal heart rates were higher. The magnitude of depressor responses increased with age, while baroreceptor reflex sensitivity initially increased over those of adults. In contrast to a decline in adult cats, functional MRI signal intensity increased significantly in dorsal and ventrolateral medullary regions and the midline raphe in the kittens during the hypotensive challenges. In addition, significant signal intensity differences emerged in cerebellar cortex and deep nuclei, dorsolateral pons, midbrain tectum, hippocampus, thalamus, and insular cortex. The altered neural responses in medullary baroreceptor reflex sites may have resulted from disinhibitory or facilitatory influences from cerebellar and more rostral structures as a result of inadequately developed myelination or other neural processes. A comparable immaturity of blood pressure control mechanisms in humans would have significant clinical implications.     

Synaptic connections of physiologically identified geniculocortical axons in kitten cortical area 17.

Single geniculocortical axons were recorded in the cortical white matter of kittens and adult cats by using micropipettes filled with horseradish peroxidase (HRP). Of 41 axons recovered in 4-5 week old kittens, three well-filled axons arborized in area 17; the remainder were incomplete or arborized in area 18. One axon had Y-like physiological properties, two were X-like. They were recovered from two 34-day-old kittens. All three axons formed clustered arborizations, mainly in layer 4A. Electron microscopic (EM) analysis of 50 boutons from kitten and 38 boutons from adult controls revealed that the boutons from kitten made synapses more frequently on spines (91% of targets) than did the boutons from the adult (71%). One X-like axon in kitten also had a collateral projection that made synapses in layer 1; this has not been seen in adult cats. In overall extent, the axons from kitten fell within the adult range.     

Temporal correlations in modulated evoked responses in the visual cortical cells of the cat

We analysed evoked responses recorded from 97 cells in the visual cortex of 4 adult cats and 8 kittens, stimulated by a drifting sinusoidal grating. A Fourier analysis of the responses allowed us to select 30 cells showing a clear modulating response (relative modulation index > 1). The 162 records from these selected cells were scanned to detect precise temporal correlations in the form of replicating triplets and associated ghost doublets. Temporal correlations of this nature were observed in these cells. They are about 10 times more abundant in adult cats than in kittens, and mostly observed in infragranular cortical layer cells. The possible role of these precise temporal patterns in information processing in the brain is examined, as well as the relation between this type of temporal correlation with coherent oscillations and principal components waveforms.     

Prevalence of species of Toxocara in dogs, cats and red foxes from the Poznan region, Poland

The prevalence of toxocariasis was evaluated for 445 dogs, 105 cats and 92 foxes from the Poznan region during 1997-1998. Forty one cats were infected (39%), 140 dogs (32%) and 15 red foxes (16%). Toxocara canis was found most frequently in puppies up to 3 months old (58%) and T. cati in kittens 4-6 months old (64%). Toxocariasis was much more prevalent amongst adult foxes (14%) than adult dogs (3%). In contrast to cats, female dogs and foxes were less infected than males. The present study suggests that cats may constitute an underestimated risk of transmission of Toxocara spp. to humans and the progressive synatropization of red foxes may also increase the sources of environmental contamination with Toxocara eggs.     

Comparative analysis of the interactions between spontaneous active neurons of the sensomotor cortex of kittens and adult cats

The character of functional interneuronal relations in the sensorimotor cortex during spontaneous neural activity in kitten and adult cats immobilized with d-tubocurarine, was studied by the method of cross-correlations of two impulse series. The data obtained by computation revealed specific age-related interneuronal connections in investigated groups of animals. In kitten aged up to 10 days, the highest percentage of the functional connections was observed which were established mainly due to the influence of a common source. In other groups of animals (kittens of 20, 30 days of postnatal life, adult cats) the common source did not play a significant role in the formation of interneuronal connections. The results showed that inhibitory connections between neurones-are established to the end of the first month of the postnatal life.     

Serologic and virologic surveys on feline herpesvirus and feline calicivirus infections in cats for experimental use

Serologic survey and virus isolation of feline herpesvirus (FHV) and feline calicivirus (FCV) were performed on cats used for research at the Laboratory Animal Research Centre, The University of Tsukuba, over the period from 1978 to 1981. Of the 507 mature and immature cats, 4 months old or older, 102 (20.1%) had HI antibody against FHV and 412 (81.3%) SN antibody against FCV. Some 23 (16.2%) and 76 (53.5%) kittens among 142 younger than 4 months had antibodies against FHV and FCV, respectively. Both the antibodies in kittens were considered to be maternally derived. The FCV antibody rate was especially high in cats weighing 2.5 kg (males) and 2.0 kg (females) or more, which were regarded as 8 to 10 months of age. An attempt was made to isolate the viruses from the oropharynx and conjunctiva of clinically healthy mature or immature cats and kittens. As the result, either one or both of the viruses were isolated from 31 of 75 mature and immature cats, and isolation rates of FHV and FCV were 6.7% and 36.0%, respectively. On the other hand, no virus was detectable in 16 kittens.     

幼猫单眼视剥夺和反缝过程中显示的双眼竞争机制

本研究以光栅为刺激所同时产生的图形视觉诱发电位和图形视网膜电图为指标,测定了单眼视剥夺和缝的新生幼猫个体在发育不同阶段的空间频率调谐曲线,并与同龃正常猫,成年正常猫进行了比较研究。结果显示,在０．１２－１．５ｃ／ｄ空间频率范围内,正常幼猫单独刺激其左眼和右眼所驱动的Ｐ－ＶＥＰ振幅相近,但都明显地比双眼驱动的为小。在单眼剥夺的幼猫,由剥夺眼所驱动的Ｐ－ＶＥＰ振幅大幅度下降,健康眼所驱动的Ｐ－ＶＥＰ则