Convergent differential regulation of SLIT‐ROBO axon guidance genes in the brains of vocal learners

Only a few distantly related mammals and birds have the trait of complex vocal learning, which is the ability to imitate novel sounds. This ability is critical for speech acquisition and production in humans, and is attributed to specialized forebrain vocal control circuits that have several unique connections relative to adjacent brain circuits. As a result, it has been hypothesized that there could exist convergent changes in genes involved in neural connectivity of vocal learning circuits. In support of this hypothesis, expanding on our related study (Pfenning et al. [2014] Science 346: 1256846), here we show that the forebrain part of this circuit that makes a relatively rare direct connection to brainstem vocal motor neurons in independent lineages of vocal learning birds (songbird, parrot, and hummingbird) has specialized regulation of axon guidance genes from the SLIT–ROBO molecular pathway. The SLIT1 ligand was differentially downregulated in the motor song output nucleus that makes the direct projection, whereas its receptor ROBO1 was developmentally upregulated during critical periods for vocal learning. Vocal nonlearning bird species and male mice, which have much more limited vocal plasticity and associated circuits, did not show comparable specialized regulation of SLIT–ROBO genes in their nonvocal motor cortical regions. These findings are consistent with SLIT and ROBO gene dysfunctions associated with autism, dyslexia, and speech sound language disorders and suggest that convergent evolution of vocal learning was associated with convergent changes in the SLIT–ROBO axon guidance pathway. J. Comp. Neurol. 523:892–906, 2015. © 2014 Wiley Periodicals, Inc.     

Distribution of choline acetyltransferase and acetylcholinesterase in vocal control nuclei of the budgerigar (Melopsittacus undulatus)

The present study used histochemical methods to map the distributions of choline acetyl transferase (ChAT) and acetylcholinesterase (AChE) in the vocal control nuclei of a psittacine, the budgerigar (Melopsittacus undulatus). The distributions of ChAT and AChE in budgerigars appeared similar to that in oscine songbirds despite evidence that these systems have evolved independently. The magnicellular nucleus of the lobus parolfactorius in budgerigars, like the area X in songbirds, contained many ChAT labeled somata, fibers, and varicosities and stained densely for AChE. In contrast, the robust nucleus of the archistriatum (RA) and the supralaminar area of the frontal neostriatum in budgerigars, like the RA and the magnicellular nucleus of the neostriatum (MAN) in songbirds, respectively, contained few or no ChAT labeled somata, fibers, and varicosities and stained lightly for AChE. The central nucleus of the lateral neostriatum in budgerigars, like the higher vocal center (HVC) in songbirds, contained no ChAT labeled somata, moderate densities of ChAT labeled fibers and varicosities, and moderate levels of AChE staining. Two nuclei, the oval nucleus of the hyperstriatum ventrale (HVo) and the oval nucleus of the anterior neostriatum (NAo), contained no ChAT labeled somata, dense ChAT labeled fibers and varicosities, and moderate to high levels of AChE staining. The HVo and the NAo have no counterparts in songbirds but may be important vocal control nuclei in the budgerigar. Cholinergic enzymes are also described in other regions which may be involved in budgerigar vocal behavior, including the basal forebrain, the torus semicircularis, and the hypoglossal nuclei (nXII). © 1996 Wiley-Liss, Inc.     

Oral language impairments in developmental disorders characterized by language strengths: A comparison of Asperger syndrome and nonverbal learning disabilities

Asperger syndrome (AS) and nonverbal learning disabilities (NLD) are developmental disorders in which linguistic ability is reported to be stronger than in disorders from which they must be distinguished for diagnosis. Children and adults with AS and NLD share pragmatic weaknesses, atypical social behaviours, and some cognitive features. To date, potential similarities between these disorders in oral language have not been directly examined in the literature. A review of the available research suggests that adequate structural language is another area of similarity for AS and NLD. However, systematic investigations of phonology, morphology, or syntax were not found; thus, the evidence for largely intact structural language in these disorders is indirect. The review also pointed to a common semantic profile across both disorders, characterized by strong vocabulary breadth in the face of limited depth and organization. These higher-order problems with semantics are proposed to be consistent with theoretical accounts of poor integrative abilities in AS and NLD, and to contribute to the well-documented pragmatic difficulties in these disorders.     

Distribution of language‐related Cntnap2 protein in neural circuits critical for vocal learning

Variants of the contactin associated protein‐like 2 (Cntnap2) gene are risk factors for language‐related disorders including autism spectrum disorder, specific language impairment, and stuttering. Songbirds are useful models for study of human speech disorders due to their shared capacity for vocal learning, which relies on similar cortico‐basal ganglia circuitry and genetic factors. Here we investigate Cntnap2 protein expression in the brain of the zebra finch, a songbird species in which males, but not females, learn their courtship songs. We hypothesize that Cntnap2 has overlapping functions in vocal learning species, and expect to find protein expression in song‐related areas of the zebra finch brain. We further expect that the distribution of this membrane‐bound protein may not completely mirror its mRNA distribution due to the distinct subcellular localization of the two molecular species. We find that Cntnap2 protein is enriched in several song control regions relative to surrounding tissues, particularly within the adult male, but not female, robust nucleus of the arcopallium (RA), a cortical song control region analogous to human layer 5 primary motor cortex. The onset of this sexually dimorphic expression coincides with the onset of sensorimotor learning in developing males. Enrichment in male RA appears due to expression in projection neurons within the nucleus, as well as to additional expression in nerve terminals of cortical projections to RA from the lateral magnocellular nucleus of the nidopallium. Cntnap2 protein expression in zebra finch brain supports the hypothesis that this molecule affects neural connectivity critical for vocal learning across taxonomic classes. J. Comp. Neurol. 522:169–185, 2014. © 2013 Wiley Periodicals, Inc.     

人脑胶质瘤中ATM、ATR、Chk1和Chk2基因表达研究

目的 研究ATM、ATR、Chk1和Chk2在人脑胶质瘤中的表达及其与肿瘤发生的关系. 方法 采用SYBRTM Green实时定量PCR技术检测35例人原发脑胶质瘤组织和10例正常脑组织中的ATM、ATR、Chk1和Chk2的表达水平. 结果 ATR、Chk1和Chk2基因在各级脑胶质瘤中表达较正常脑组织升高,差异均有统计学意义(P<0.05).其中,ATR和Chk2基因表达在Ⅱ级、Ⅲ级、Ⅳ级胶质瘤组织之间差异均无统计学意义(P0.05),而Chk1,在Ⅳ级胶质瘤中的表达较Ⅱ级、Ⅲ级胶质瘤明显升高,差异均有统计学意义(P<0.05).ATM基因表达量在正常脑组织和各级脑胶质瘤中差异无统计学意义(P0.05). 结论 ATR、Chk1和Chk2在人脑胶质瘤中表达上调,说明这些基因可能与人脑胶质瘤的发生有关.其中,Chk1表达与肿瘤恶性程度有关.可作为判别胶质瘤病理级别的辅助指标.     

Contactin‐associated protein‐like 2, a protein of the neurexin family involved in several human diseases

Contactin‐associated protein‐like 2 (CASPR2) is a cell adhesion protein of the neurexin family. Proteins of this family have been shown to play a role in the development of the nervous system, in synaptic functions, and in neurological diseases. Over recent years, CASPR2 function has gained an increasing interest as demonstrated by the growing number of publications. Here, we gather published data to comprehensively review CASPR2 functions within the nervous system in relation to CASPR2‐related diseases in humans. On the one hand, studies on Cntnap2 (coding for CASPR2) knockout mice revealed its role during development, especially, in setting‐up the inhibitory network. Consistent with this result, mutations in the CNTNAP2 gene coding for CASPR2 in human have been identified in neurodevelopmental disorders such as autism, intellectual disability, and epilepsy. On the other hand, CASPR2 was shown to play a role beyond development, in the localization of voltage‐gated potassium channel (VGKC) complex that is composed of TAG‐1, Kv1.1, and Kv1.2. This complex was found in several subcellular compartments essential for action potential propagation: the node of Ranvier, the axon initial segment, and the synapse. In line with a role of CASPR2 in the mature nervous system, neurological autoimmune diseases have been described in patients without neurodevelopmental disorders but with antibodies directed against CASPR2. These autoimmune diseases were of two types: central with memory disorders and temporal lobe seizures, or peripheral with muscular hyperactivity. Overall, we review the up‐to‐date knowledge on CASPR2 function and pinpoint confused or lacking information that will need further investigation.     

Distribution,number, and certain neurochemical identities of infracortical white matter neurons in the brains of three megachiropteran bat species

A large population of infracortical white matter neurons, or white matter interstitial cells (WMICs), are found within the subcortical white matter of the mammalian telencephalon. We examined WMICs in three species of megachiropterans, Megaloglossus woermanni, Casinycteris argynnis, and Rousettus aegyptiacus, using immunohistochemical and stereological techniques. Immunostaining for neuronal nuclear marker (NeuN) revealed substantial numbers of WMICs in each species—M. woermanni 124,496 WMICs, C. argynnis 138,458 WMICs, and the larger brained R. aegyptiacus having an estimated WMIC population of 360,503. To examine the range of inhibitory neurochemical types we used antibodies against parvalbumin, calbindin, calretinin, and neural nitric oxide synthase (nNOS). The calbindin and nNOS immunostained neurons were the most commonly observed, while those immunoreactive for calretinin and parvalbumin were sparse. The proportion of WMICs exhibiting inhibitory neurochemical profiles was ~26%, similar to that observed in previously studied primates. While for the most part the WMIC population in the megachiropterans studied was similar to that observed in other mammals, the one feature that differed was the high proportion of WMICs immunoreactive to calbindin, whereas in primates (macaque monkey, lar gibbon and human) the highest proportion of inhibitory WMICs contain calretinin. Interestingly, there appears to be an allometric scaling of WMIC numbers with brain mass. Further quantitative comparative work across more mammalian species will reveal the developmental and evolutionary trends associated with this infrequently studied neuronal population.     

Sexual dimorphism and lack of seasonal changes in vocal control regions of the white-crowned sparrow brain

The volumes of brain regions involved in vocal control were measured in adult female white-crowned sparrows (Zonotrichia leucophrys nuttali) captured in the summer, and in captive males held on long-day or short-day photoperiods. There is a large sex difference in the volume of two nuclei, the caudal nucleus of the hyperstriatum ventrale (HVc) and the robust nucleus of the archistriatum (RA), which correlates with a large sex difference in singing behavior. There were no differences in the size of HVc and RA in adult males held on summer or winter photoperiods, even though the ‘summer’ males had high androgen levels and were singing, whereas the ‘winter’ males had regressed testes and were not singing. The data bear on hypotheses concerning the relationship between size of brain nuclei and song learning.     

Pre-ischemia electro-acupuncture potentiates the expression of Bcl-2 and transforming growth factor-beta 1 in rat brains

The expression of the anti-apoptotic molecules Bcl-2 and transforming growth factor-beta 1 is known to confer protective effects on the cerebral ischemia-reperfusion injury.The current study investigated the expression levels of Bcl-2 and transforming growth factor-beta 1 in response to multiple pre-ischemia electro-acupuncture at acupoints Zusanli(ST36)and Fengchi(GB20) stimulation.Rats were divided into five groups:uninjured,control,non-acupoint,GB20 and ST36. Rats in the non-acupoint,GB20 and ST36 groups received 30 minutes(3 times or 18 times)of electro-acupuncture stimulation before experimental cerebral ischemia was induced.Bcl-2 and transforming growth factor-beta 1 were found to be significantly increased in the ST36 groups with either 3 or 18 electro-acupuncture treatments(P<0.05).The production was higher with 18 electro-acupuncture treatments in the ST36 groups(P<0.05).In the GB20 groups,significant increase was only observed in transforming growth factor-beta 1 with 18 electro-acupuncture treatments(P<0.05).No significant elevation of the level of transforming growth factor-beta 1 was observed in the non-acupoint groups.However,the production of Bcl-2 increased with 18 treatments in the non-acupoint groups(P<0.05).The data suggest that multiple pre-ischemia electro-acupuncture at ST36 was effective in conferring neuroprotective effect on the brain by means of upregulation of Bcl-2 and transforming growth factor-beta 1 and the effect was increase with the number of treatment.     

G422胶质瘤冷冻后细胞凋亡及相关基因表达的研究

目的：探讨冷冻杀伤肿瘤细胞的分子机制。方法；建立小鼠脑胶质瘤动物模型；用末端标记法（TUNEL）原位检测细胞凋亡，DNA琼脂糖电泳观察DNA梯形条带；用免疫组织化学ABC法检查bcl-2和bax表达。结果：不同冻融周期作用于G422胶质瘤后，在不同时间点、冷冻灶周边区的肿瘤细胞出现了形态学和DNA水平上的细胞凋亡变化，其峰值出现在冷冻后24-48h。重复冻融出现更多的凋亡细胞。不同冻融周期均引起冷冻灶周边区细胞bax上调，但对抑凋亡基因bcl-2表达无明显影响。结论：冷冻治疗可以诱导G422胶质瘤细胞凋亡，冷冻诱导的细胞凋亡由bax基因参与介导，而与bcl-2表达无关。诱导细胞凋亡可能 是冷冻杀伤肿瘤细胞的重要机制。     

Enhancement of Y-maze learning by piracetam, 2-thio-1-pyrrolidine-acetamide and 2-thio-1-pyrrolidine-thio-acetamide in rats

Summary Learning of rats given either piracetam, 2-thio-1-pyrrolidine-acetamide (thioacet) or 2-thio-1-pyrrolidine-thio-acetamide (thiothio) was studied in order to investigate nootropic effects of the compounds. Learning ability was measured using a Y-maze with water reward for the correct choice in a black-white discrimination task. Thioacet and thiothio enhanced learning ability of the rats at doses that were 2.5–10 times lower than those required for obtaining nootropic effects of piracetam. Thus the thioderivatives of piracetam might be of value for studying mechanisms of action of nootropic drugs.     

Interleukin-1beta induces anorexia but not spatial learning and memory deficits in the rat

Sickness behaviors are a set of adaptive responses to infection that include lethargy, anorexia, and, of direct relevance to this work, learning and memory impairments. The proinflammatory cytokine, interleukin-1 beta (IL-1β) has been proposed as the primary peripheral mediator of these sickness behaviors, though few studies have investigated the effects of peripheral IL-1β on learning and memory. We used three different versions of the Morris water task (Morris water task), a spatial learning and memory task, to separately assess the effects of peripheral IL-1β on acquisition, consolidation, and retention of spatial location information. Using a dose that induced anorexia, assessed as a significant reduction in body weight, we observed no performance impairments in the IL-1β-treated rats across the different versions of the task, suggesting that peripheral IL-1β alone is insufficient to induce spatial learning and memory impairments in the rat. The observed dissociation of anorexia and cognitive dysfunction suggests that, either spatial learning and memory are not principal components of the sickness response, or cognitive dysfunction requires different or additional peripheral mediator(s).     

GEFS+ is not related to the most common mutations of SCN1B,SCN1A and GABRG2 in two Tunisian families

The objective was to investigate whether the described mutations of the SCN1A, SCN1B and GABRG2 genes are associated to generalised epilepsy with febrile seizure plus (GEFS+) in two Tunisian families. We performed a genetic study of two multigenerational Tunisian families with GEFS+ spectrum. The molecular analysis included a PCR amplification of SCN1B, SCN1A and GAGRG2 exons, then a screening of the known SCN1B, SCN1A and GABRG2 gene mutations by direct sequencing. The data excluded the involvement of all known published mutations. However, an insertion of a T nucleotide at a heterozygous state within the intron 12 of the SCN1A gene has been identified in two probands and their parents. Our results corroborate the genetic heterogeneity of GEFS+ predominantly in epilepsy patients of different countries and ethnic groups.