Comparative distribution of NADPH-diaphorase activity and tyrosine hydroxylase immunoreactivity in the diencephalon and mesencephalon of the domestic chicken (Gallus domesticus)

We described the distribution of NADPH-diaphorase-containing neurons in relation to tyrosine hydroxylase immunoreactivity in the diencephalon and mesencephalon of the chicken. In the diencephalon, both markers were found in the lateral hypothalamus, dorsal hypothalamic area, hypothalamic periventricular nucleus, paraventricular nucleus and mamillary area. A close examination showed that the fine distribution of these markers differed slightly, so that they were never observed in the same neurons. In the mesencephalon, NADPH-diaphorase and tyrosine hydroxylase immunoreactivity were found in the ventral pedunculopontine area (nucleus tegmenti pedunculopontinus pars compacta, adjacent areas surrounding the quintofrontal tract and the nucleus mesencephalicus profundus ventralis), the coeruleus complex (locus coeruleus, ventral and dorsal subcoeruleus nuclei), the ventral tegmental area and the central gray. The majority of these neurons contained either diaphorase or tyrosine hydroxylase. Nevertheless, in a few cases both markers appeared to colocalize in the same neuron, typically in large perikarya of the ventral pedunculopontine area.Abbreviations AVT Ventral tegmental area of Tsai - DAB diaminobenzidine - DHA dorsal hypothalamic area - DMA anterior dorsomedial thalamic nucleus - DMP posterior dorsomedial thalamic nucleus - DSV ventral supraoptic decussation - GCt central gray - ICH intercalated hypothalamic nucleus - IH inferior hypothalamic nucleus - LHy lateral hypothalamic area - LoC locus coeruleus - ML lateral mamillary nucleus - MM medial mamillary nucleus - MPv ventral part of the deep mesencephalic nucleus - nI interstitial nucleus of Rendahl - NADPH-d NADPH-diaphorase - NGS normal     

Isolation of surface membranes from neuronal and non-neuronal cell populations from embryonic chick brain. Opiate receptor activity of neuronal membranes

Surface membranes were isolated from neuronal and non-neuronal cell populations prepared from embryonic chick brain. Sodium dodecyl sulfate gel electrophoresis showed that membranes from the two cell populations have distinctly different protein compositions. The neuronal cell membranes have opiate receptor activity with high- and low-affinity binding sites similar to those determined for intact neuronal cells.     

Functional MRI activation patterns of cerebellum in patients with epilepsy and brain tumors

Function of cerebellum in control and coordination of motor function has been well established for several years. Recent functional magnetic resonance imaging (MRI) studies reveal activation of cerebellum with memory, speech and language tasks. We hypothesize that during every function in the brain signals are relayed to cerebellum. We seek to analyze cognitive, emotional and social functions of cerebellum in patients with brain tumors and epilepsy utilizing functional Magnetic Resonance Imaging. Fifty‐one consecutive adult patients who underwent functional MRI examination were retrospectively analyzed for various activation patterns involving cerebellum. The neuropsychological battery of tasks assessed motor, language, memory, visual and auditory functions. Cognitive ability of all participants was assessed by Montreal cognitive assessment (MOCA). Patterns were analyzed for specific lobes and locations in the cerebellum. We found that simultaneous cerebellar activation is a consistent finding with brain activation during every functional MRI task that we tested except visual task. The patterns of functional MRI cerebellar activation were similar in both patient subgroups and control subjects compared to previously described patterns in normal subjects. Clin. Anat. 32:1053–1060, 2019. © 2019 Wiley Periodicals, Inc.     

Ptbp2 represses adult-specific splicing to regulate the generation of neuronal precursors in the embryonic brain

Two polypyrimidine tract RNA-binding proteins (PTBs), one near-ubiquitously expressed (Ptbp1) and another highly tissue-restricted (Ptbp2), regulate RNA in interrelated but incompletely understood ways. Ptbp1, a splicing regulator, is replaced in the brain and differentiated neuronal cell lines by Ptbp2. To define the roles of Ptbp2 in the nervous system, we generated two independent Ptbp2-null strains, unexpectedly revealing that Ptbp2 is expressed in neuronal progenitors and is essential for postnatal survival. A HITS-CLIP (high-throughput sequencing cross-linking immunoprecipitation)-generated map of reproducible Ptbp2-RNA interactions in the developing mouse neocortex, combined with results from splicing-sensitive microarrays, demonstrated that the major action of Ptbp2 is to inhibit adult-specific alternative exons by binding pyrimidine-rich sequences upstream of and/or within them. These regulated exons are present in mRNAs encoding proteins associated with control of cell fate, proliferation, and the actin cytoskeleton, suggesting a role for Ptbp2 in neurogenesis. Indeed, neuronal progenitors in the Ptbp2-null brain exhibited an aberrant polarity and were associated with regions of premature neurogenesis and reduced progenitor pools. Thus, Ptbp2 inhibition of a discrete set of adult neuronal exons underlies early brain development prior to neuronal differentiation and is essential for postnatal survival.     

Genome-sequenee Analysis of the Pathogenic H5N1 Avian Influenza A Virus Isolated in China in 2004

Analysis of the sequences of the genome of the avian influenza A/chicken/Hubei/327/2004 (H5N1) virus, isolated from a poultry farm during the outbreak of avian influenza (AI) in Hubei Province, central China, in the spring of 2004, revealed that the hemagglutinin (HA) gene of the virus was genetically similar to those of the H5 highly pathogenic avian influenza virus (HPAI). Notably, the neuraminidase gene of the virus had a 20-amino acid deletion in the stalk region and a 5-amino acid deletion in the NS gene which belonged to allele B. Furthermore, the internal genes (PB2, PA, NP, M2) of the A/chicken/Hubei/327/2004 virus with the particular amino acid residues were more closely related to H5N1 viruses of 2000–2003 isolated in Hong Kong and the AIV of Thailand and Vietnam in 2004, but less likely to evolve from the viruses of Hong Kong 1997. Finally, our results demonstrated that the influenza A/chicken/Hubei/327/2004 (H5N1) virus was similar to those of the AI viruses isolated from Hong Kong (2000–2003), Vietnam, and Thailand rather than the viruses from the 1997 lineage of Hong Kong and with closest genetic relatives to the influenza A/Chicken/Hong Kong/61.9/02 (H5N1) virus. These data suggest that the influenza A/chicken/Hubei/327/2004 (H5N1) virus which circulated in central China derived its internal gene from a virus similar to the influenza A/Chicken/Hong Kong/61.9/02 (H5N1) virus.     

难治性癫痫模型大鼠脑组织中srGAP2分子的表达

背景：众多研究结果显示srGAP2分子在突起生长和突触可塑性起到关键的作用,但具体机制不明。 目的：检测srGAP2在致痫大鼠模型中的表达,探讨srGAP2与难治性癫痫发病机制的相关性。 方法：选取雄性SD大鼠56只随机分为7组,其中随机选取6组建立癫痫模型,构成实验组,剩余1组作为对照组。分别选取癫痫发作后的6 h、1 d、1周、2周、1个月、2个月等6个时间点的颞叶脑组织作为研究对象,并与对照组进行比较。利用免疫组织化学、免疫荧光以及免疫印迹3种方法检测srGAP2在致痫动物模型以及对照组的脑组织中的表达及变化规律。 结果与结论：实验组中srGAP2除在皮质区表达增高外,还在海马区高表达,与对照组相比各时间点srGAP2在颞叶癫痫动物组中的表达含量逐渐升高,且在2周左右达高峰并维持,到2个月左右降至接近对照组水平。结果提示srGAP2可能通过促进苔藓纤维出芽,进而导致脑组织中异常神经网络的建立,并最终在难治性癫痫的发生发展中起到重要作用。     

颞叶外侧癫痫患者脑组织NHE1及凋亡相关蛋白的表达

目的　检测颞叶外侧癫痫患者手术切除脑组织标本中钠氢交换体1（Na+/H+ exchanger-1,NHE1）的表达及凋亡相关蛋白的表达,初步探讨其致病机制。 方法　收集16例颞叶外侧癫痫患者手术切除脑组织标本作为癫痫组,10例颞叶肿瘤和脑出血患者手术切除脑组织标本作为对照组,HE染色观察脑组织病理学变化,免疫组化染色法以及免疫荧光法检测NHE1表达特点,Western blot等方法半定量分析NHE1蛋白表达特点,并检测凋亡相关蛋白Bcl-2与Bax表达特点。 结果　HE染色可见癫痫组颞叶组织中神经元明显减少,吞噬现象明显增多,小胶质细胞过度活跃,而对照组标本无类似表现;免疫荧光及免疫组化染色提示NHE1定位于神经元上,癫痫组NHE1染色较对照组增强（P<0.05）;癫痫组NHE1蛋白半定量表达较对照组增高（P<0.05）;凋亡相关蛋白检测显示癫痫组Bcl-2蛋白表达较对照组降低（P<0.05）,Bax蛋白表达较对照组增高（P<0.05）。 结论　NHE1与颞叶外侧癫痫的形成和发展密切相关,其机制可能是NHE1增高参与调控神经元凋亡。     

Incorporation of embryonic CA3 cell grafts into the adult hippocampus at 4-months after injury: effects of combined neurotrophic supplementation and caspase inhibition

As receptivity of the injured hippocampus to cell grafts decreases with time after injury, strategies that improve graft integration are necessary for graft-mediated treatment of chronic neurodegenerative conditions such as temporal lobe epilepsy. We ascertained the efficacy of two distinct graft-augmentation strategies for improving the survival of embryonic day 19 hippocampal CA3 cell grafts placed into the adult hippocampus at 4-months after kainic acid induced injury. The donor cells were labeled with 5'-bromodeoxyuridine, and pre-treated and grafted with either brain-derived neurotrophic factor, neurotrophin-3 and a caspase inhibitor or fibroblast growth factor and caspase inhibitor. The yield of surviving grafted cells and neurons were quantified at 2-months post-grafting. The yield of surviving cells was substantially greater in grafts treated with brain-derived neurotrophic factor, neurotrophin-3 and caspase inhibitor (84%) or fibroblast growth factor and caspase inhibitor (99% of injected cells) than standard cell grafts (26%). Because approximately 85% of surviving grafted cells were neurons, increased yield in augmented groups reflects enhanced survival of grafted neurons. Evaluation of the mossy fiber synaptic re-organization in additional kainic acid-lesioned rats receiving grafts enriched with brain-derived neurotrophic factor, neurotrophin-3 and caspase inhibitor at 3-months post-grafting revealed reduced aberrant dentate mossy fiber sprouting in the dentate supragranular layer than "lesion-only" rats at 4 months post-kainic acid, suggesting that some of the aberrantly sprouted mossy fibers in the dentate supragranular layer withdraw when apt target cells (i.e. grafted neurons) become available in their vicinity. Thus, the yield of surviving neurons from CA3 cell grafts placed into the adult hippocampus at an extended time-point after injury could be enhanced through apt neurotrophic supplementation and caspase inhibition. Apt grafting is also efficacious for reversing some of the abnormal synaptic reorganization prevalent in the hippocampus at later time-points after injury.     

难治性癫痫二次手术41例患者脑切除标本临床病理学分析

目的分析并比较接受第二次癫痫外科手术的难治性癫痫患者脑切除标本的临床病理学特点。方法回顾性分析2008~2013年在北京市海淀医院功能神经科接受第二次手术治疗的41例难治性癫痫患者的临床资料及病理资料,并复习相关文献。结果 41例患者中男性28例,女性13例,发病年龄1~51岁(平均10.29岁),病程2~30年(平均11.91年),第二次手术距第一次手术0.5~20年(平均7.05年)。脑切除标本病理诊断为FCDⅢa者8例(19.51%),FCDⅢb者11例(26.83%),FCDⅢd者15例(36.59%),双重病理7例占17.07%(5例为FCDⅢa伴胶质瘢痕/瘢痕脑回,1例为FCDⅢa伴血管瘤,1例为FCDⅢa伴混合性少突星形细胞瘤)。术后随访0.5~5年,EngelⅠ级25例(61.0%),EngelⅡ级14例(34.1%),EngelⅢ级1例(2.45%),失访1例(2.45%)。颞叶癫痫20例(占48.78%)。结论接受第二次癫痫外科手术的难治性癫痫患者脑切除标本病理类型仅包括FCDⅢ型和双重病理。这两种类型的患者再次手术后,效果良好,EngelⅠ级和EngelⅡ级共占95.1%。获得性脑损伤(如高热惊厥、外伤、难产等和脑肿瘤切除术后)致胶质瘢痕的形成和脑功能重建的过程、颞叶及内侧结构未能完全切除、肿瘤复发及致痫灶切除范围不够,是再次行癫痫外科手术的主要原因;精准完整的术前评估可以有效地减少再次手术的风险。     

Focal irradiation of the brain: An alternative to temporal lobe resection in intractable focal epilepsy?

Reconciling the early promising results of radiation therapy in the treatment of epilepsy with the recent theory concerning the role of nonsynaptic mechanisms in focal epileptogenesis, it is suggested that the potential of irradiation as an alternative to temporal lobe resection in intractable epilepsy should be re-evaluated.     

Dopaminergic neuronal survival and the effects of bFGF in explant,three dimensional and monolayer cultures of embryonic rat ventral mesencephalon

Embryonic substantia nigra cells when transplanted into the striatum can reverse many of the defects of Parkinson's disease. The efficacy of such grafts is compromised by the poor survival of grafted dopaminergic neurones; typically, 3–10% survive transplantation. We used three tissue culture models to identify stages in the procedure for the preparation and insertion of grafts which might be responsible for this cell death and to identify environments in which survival is optimised. (1) The ventral mesencephalon was dissected from the donor brain, then placed immediately into culture contained in a collagen gel. (2) The dissected tissue fragments were enzymatically dissociated, then the cells placed into monolayer culture. (3) Enzymatically dissociated tissue was packed into 0.5-mm-diameter porous tubes, to simulate the compaction of cells into a graft deposit in the host brain. Dissociation of the tissue by itself caused the death of approximately 30% of dopaminergic neurones, as judged by the difference in cell counts between the intact embryonic day 14 (E14) mesencephalon, and cells dissociated then packed into tubes. Of the dissociated neurones approximately 60% died during the first 24 h and 87% during the first 3 days in monolayer culture, while only 7% of dopaminergic neurones in three-dimensional cultures and 11% of neurones in explant cultures died over the first 3 days. Embryonic dopaminergic neurones are clearly very vulnerable to adverse conditions during the first days after their removal from the donor brain. The excellent survival of neurones in three-dimensional and explant cultures indicates that close association with other cells, which may provide greatly improved access to trophic factors, can enable the cells to survive this period of vulnerability. In contrast to its effects in monolayer cultures, bFGF had no effect on dopaminergic neuronal survival in either explant or three-dimensional cultures.     

Pharmacological characterization, anatomical distribution and sex differences of the non-NMDA excitatory amino acid receptors in the quail brain as identified by CNQX binding

The distribution of non-N-methyl-d-aspartate binding sites was studied in coronal and sagittal sections through the brain of adult Japanese quail by quantitative autoradiography, using tritiated 6-cyano-7-nitroquinoxaline-2,3-dione as a radioligand. Saturation binding experiments were, in addition, carried out in areas showing high levels of binding (cerebellar molecular layer, nucleus anterior medialis and nucleus infundibularis) and demonstrated that the binding of tritiated ligand was specific and saturable. Competition studies with α-amino-3-hydroxy-methyl-4-isoxazole propionic acid and kainic acid indicated that kainic acid strongly inhibited ligand binding in all brain areas. α-Amino-3-hydroxy-methyl-4-isoxazole propionic acid was only a weak inhibitor in the hypothalamic nuclei whereas in the cerebellar molecular layer both high and low affinity inhibitions were detected. The highest binding levels of tritiated ligand were observed in the molecular layer of the cerebellum. Very high levels of binding were detected in various preoptic/hypothalamic sites including the nucleus suprachiasmaticus pars medialis, nucleus anterior medialis hypothalami, nucleus infundibularis, nucleus mammillaris medialis, nucleus posteromediale hypothalami and nucleus hypothalami ventromedialis. High levels of binding were also detected in the bulbus olfactorius, bed nucleus commissuralis anterior, bed nucleus commissuralis pallii, nucleus accumbens, bed nucleus striae terminalis and nucleus interpeduncularis. In the preoptic area/hypothalamus, high levels of binding were clearly present in all areas that contain gonadotropin releasing hormone cells or fibers. In the pons and mesencephalon, moderate levels of binding were associated with catecholaminergic areas such as the area ventralis tegmentalis (area ventralis of Tsai) and the locus coeruleus. Saturation analysis demonstrated the presence of a higher number of binding sites in females than in males in the cerebellar molecular layer, nucleus infundibularis and nucleus anterior medialis. This latter difference was confirmed in the one point assays that also identified higher levels of specific binding in the nucleus suprachiasmaticus pars medialis of males as compared with females. These anatomical data suggest a possible implication of non-N-methyl-d-aspartate receptors in the synthesis and/or release of both gonadotropin releasing hormone and catecholaminergic neurotransmitters that should now be tested by pharmacological experiments.     

Automated EEG signal analysis for identification of epilepsy seizures and brain tumour

Abstract

Electroencephalography (EEG) is a clinical test which records neuro-electrical activities generated by brain structures. EEG test results used to monitor brain diseases such as epilepsy seizure, brain tumours, toxic encephalopathies infections and cerebrovascular disorders. Due to the extreme variation in the EEG morphologies, manual analysis of the EEG signal is laborious, time consuming and requires skilled interpreters, who by the nature of the task are prone to subjective judegment and error. Further, manual analysis of the EEG results often fails to detect and uncover subtle features. This paper proposes an automated EEG analysis method by combining digital signal processing and neural network techniques, which will remove error and subjectivity associated with manual analysis and identifies the existence of epilepsy seizure and brain tumour diseases. The system uses multi-wavelet transform for feature extraction in which an input EEG signal is decomposed in a sub-signal. Irregularities and unpredictable fluctuations present in the decomposed signal are measured using approximate entropy. A feed-forward neural network is used to classify the EEG signal as a normal, epilepsy or brain tumour signal. The proposed technique is implemented and tested on data of 500 EEG signals for each disease. Results are promising, with classification accuracy of 98% for normal, 93% for epilepsy and 87% for brain tumour. Along with classification, the paper also highlights the EEG abnormalities associated with brain tumour and epilepsy seizure.     

Changes in oscillatory activity of neurons in the medial septal area in animals with a model of chronic temporal epilepsy

Comparative studies of the activity of extracellularly recorded neurons in living slices of the medial septal area of healthy guinea pigs and animals with a model of chronic temporal epilepsy demonstrated differences between them in terms of the frequency and pattern of cell discharges. The brains of animals with experimental epilepsy showed a doubling of the total level of activity as compared with controls, due to increases in the discharge frequencies of irregular and regular non-volleying neurons. There was a sharp (three-fold) increase in the number of cells with rhythmic discharge volleys, along with changes in the parameters of volley activity — both in neurons with the endogenous (pacemaker) pattern and in cells with secondary involvement in rhythmic activity. The possible mechanisms for these changes are discussed. These data widen our understanding of the processes forming pathological synchronization in epilepsy and may assist in the creation of new approaches to the treatment of this disease. __________ Translated from Zhurnal Vysshei Nervnoi Deyatel'nosti imeni I. P. Pavlova, Vol. 57, No. 5, pp. 618–623, September–October, 2007.     

神经营养素-4在成年猴脑的分布

目的 :为探讨神经营养素 4(Neurotrophin 4,NT 4)在成年灵长类动物猴脑的分布及功能提供有用的形态学依据。方法 :免疫组织化学SP法。结果 :NT 4 IR(Neurotrophin 4immunoreactive)分布于大脑皮层Ⅲ Ⅴ层的部分神经元胞体及突起以及白质内少量的神经胶质细胞 ;小脑皮质及白质内的部分神经元 ;海马CA1、CA2 、CA3区的部分神经元 ;此外豆状核、尾状核、脑桥核、前庭神经核、薄、契束核、副神经核等可见散在阳性反应细胞及交织成网的纤维。结论 :NT 4 IR广泛地分布于猴脑的多种组织和细胞 ,提示其功能可能涉及不同类型的神经元及可能的非神经元     

Lateralization of choline acetyltransferase (ChAT) activity in fetus and adult human brain

Choline acetyltransferase (ChAT) activity was measured in the first temporal gyrus (Brodmann area 22) and in the gyrus precentrale (Brodmann area 4) of both hemispheres in post-mortem human fetus and adult brains. In fetal brains the ChAT values were higher in the right first temporal gyrus in comparison to the left one (P < 0.05). Conversely in adult brains ChAT activity was higher in the left first temporal gyrus than in the controlateral one (P < 0.05). Absolute values of ChAT were similar in the right first temporal gyrus of fetus and adult brains. No asymmetry was found in the fetal and adult gyrus precentrale. These findings could be interpreted in terms of differential rates of development of cholinergic synapses in left and right human temporal lobes.     

Protein chimeras containing the Mycoplasma bovis GAPDH protein and bovine host-defence peptides retain the properties of the individual components

Besides the well characterized role in glycolysis, glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has been implicated in virulence of pathogenic micro-organisms and because of its cell surface location, it has been shown to act as an adhesin for colonization of tissue surfaces both for pathogenic and non-pathogenic normal microflora. These novel properties of GAPDH make this protein a target for studies in pathogenesis and a candidate for vaccine development against several diseases. Previously, we have isolated the GAPDH protein of Mycoplasma bovis and we are currently using this protein as a test antigen to develop a vaccine to protect feedlot animals from M. bovis-related diseases. As part of our vaccine studies, we are testing several novel immune modulators, some of which are host-defence peptides (HDP). HDP are small protein molecules that are part of the innate immune system of the host possess antimicrobial activities and can act as adjuvants. These novel compounds have been used as part of chimeric proteins composed of viral antigens fused to HDP and these chimeras were found to promote immune responses. The first step in the use of the M. bovis GAPDH protein and HDP as components of a vaccine was to construct M. bovis GAPDH-HDP chimeric proteins. The three M. bovis GAPDH-HDP chimeric proteins constructed here: GAPDH-BMAP28 (sGap-M), GAPDH-indolicidin (sGap-I), and GAPDH-TAP (Gap-T) retained properties associated with the individual components, namely GAPDH enzymatic and HDP antimicrobial activities.     

Histochemical distribution of zinc in the brain of the zebra finch (Taenopygia guttata)

The distribution of zinc was studied in the brain of the zebra finch (Taenopygia guttata) by means of the selenium histochemical method. A specifie pattern was seen, which usually correlated with the main known architectonic subdivisions. In addition, a few as yet unidentified structures were observed. In the telencephalon, the pallial components were stained with moderate to strong intensity. The only exceptions were the hyperstriatum intercalatus superior, a small medial area in the hyperstriatum accessorium and in the dorsolateral cortex, and the dorsomedial part of the hippocampal complex, which were virtually devoid of staining. Staining of the dorsal ventricular ridge components varied considerably. The archistriatum, the nucleus accumbens, the nucleus of the stria terminalis, the hyperstriatum ventrale and the lateral septum showed moderate to strong staining. The medial septum was weakly stained. The neostriatum showed a rather complex pattern of staining with unstained areas, such as the magnocellular nucleus of the anterior neostriatum, and other parts intensely stained, especially in its caudal region. Both paleostriatii primitivum and augmentatum showed a rostro-caudal gradient that was increasingly stained. We also observed an intensely stained area ventral to the fasciculus prosencephali lateralis and lateral to the tractus septomesencephalicus, a weakly to moderately stained band ventral to the lobus parolfactorius, an intensely stained zone along the lateral ventricle in the hyperstriatum ventrale, and an unstained almond-shaped nucleus in the lateral hyperstriatum ventrale. In the diencephalon, the hypothalamus showed a moderate to strong, rather uniform staining, whereas the thalamus was usually weakly to moderately stained, with the exception of a few unstained nuclei. Only the lateral nucleus of the habenula was stained, and with strong intensity. Most of the mesencephalon stained rather uniformly with a moderate to strong intensity. The most intense staining was seen in the substantia grisea centralis, the substantia grisea et fibrosa periventricularis, the torus semicircularis and the nucleus intercollicularis. The tectum opticum was virtually devoid of stain except for two light bands in the stratum griseum et fibrosum superficiale. The formatio reticularis was moderately stained. All the other structures were either weakly stained or unstained. Some staining was seen in the Purkinje and the granular layers of tha cerebellum, as well as around its internal nuclei. The pons and the medulla oblongata showed an overall moderate to intense staining, with the exception of a few unstained nuclei. When compared in three bird species belonging to different genera, zinc distribution shows remarkable similarities, despite species, age and methodological differences. The pattern of zinc staining suggests that this element may play an important role in integrative and autonomic functions.     

Prenatal acoustic stimulation influences neuronal size and the expression of calcium-binding proteins (calbindin D-28K and parvalbumin) in chick hippocampus

Prenatal auditory enrichment by species-specific sounds and sitar music enhances the expression of immediate early genes, synaptic proteins and calcium binding proteins (CaBPs) as well as modifies the structural components of the brainstem auditory nuclei and auditory imprinting area in chicks. There is also facilitation of postnatal auditory preference of the chicks to maternal calls following both types of sound stimulation indicating prenatal perceptual learning. To examine whether the sound enrichment protocol also affects the areas related to learning and memory, we assessed morphological changes in the hippocampus at post-hatch day 1 of control and prenatally sound-stimulated chicks. Additionally, the proportions of neurons containing calbindin D-28K and parvalbumin immunoreactivity as well as their protein levels were determined. Fertilized eggs of domestic chick were incubated under normal conditions of temperature, humidity, forced draft of air as well as light and dark (12:12 h) photoperiods. They were exposed to patterned sounds of species-specific and sitar music at 65 dB for 15 min per hour over a day/night cycle from day 10 of incubation till hatching. The hippocampal volume, neuronal nuclear size and total number of neurons showed a significant increase in the music-stimulated group as compared to the species-specific sound-stimulated and control groups. However, in both the auditory-stimulated groups the protein levels of calbindin and parvalbumin as well as the percentage of the immunopositive neurons were increased. The enhanced proportion of CaBPs in the sound-enriched groups suggests greater Ca²⁺ influx, which may influence long-term potentiation and short-term memory.