Migratory Stream Research Articles

Intranasal delivery of mitochondria for treatment of Parkinson\u2019s Disease model rats lesioned with 6-hydroxydopamine

The feasibility of delivering mitochondria intranasally so as to bypass the blood–brain barrier in treating Parkinson's disease (PD), was evaluated in unilaterally 6-OHDA-lesioned rats. Intranasal infusion of allogeneic mitochondria conjugated with Pep-1 (P-Mito) or unconjugated (Mito) was performed once a week on the ipsilateral sides of lesioned brains for three months. A significant improvement of rotational and locomotor behaviors in PD rats was observed in both mitochondrial groups, compared to sham or Pep-1-only groups. Dopaminergic (DA) neuron survival and recovery > 60% occurred in lesions of the substantia nigra (SN) and striatum in Mito and P-Mito rats. The treatment effect was stronger in the P-Mito group than the Mito group, but the difference was insignificant. This recovery was associated with restoration of mitochondrial function and attenuation of oxidative damage in lesioned SN. Notably, P-Mito suppressed plasma levels of inflammatory cytokines. Mitochondria penetrated the accessory olfactory bulb and doublecortin-positive neurons of the rostral migratory stream (RMS) on the ipsilateral sides of lesions and were expressed in striatal, but not SN DA neurons, of both cerebral hemispheres, evidently via commissural fibers. This study shows promise for intranasal delivery of mitochondria, confirming mitochondrial internalization and migration via RMS neurons in the olfactory bulb for PD therapy.

Effect of international labor mobility on social-economic development of countries

The goal of the research is the specification of the effect of international mobility of labor resources on the social-economic development of a country, as well as the impact on the GDP volume. The main purpose set in the investigation is the study of international experience of the problem solution. Another goal of the research work is the international mobility of labor resources in conditions of national economy. The methods of analysis, grouping and analogy were used in the investigation. In the research work carried out by the author, the properties of international mobility of labor resources were commented, the factors and reasons of their occurrence specified as well. The analysis has been conducted and the system of effect mobility of labor resources on GDP growth in some countries and their impact on the state of labor market developed. Due to the research surveys, the reasons for development of international mobility of labor resources and direction of labor migration streams in Azerbaijan have been identified. The impact of international mobility of labor resources on social-economic development has been evaluated. Positive and negative impact of international mobility of labor resources on social-economic development of Azerbaijan, as well as setting measures on migrant admission as contributing country in case of negative effect have been specified in the innovation of research. Practical significance of the investigation lies in the regulation of international mobility of labor resources, introduction with experience of difference countries by the system of statistical figures and formation of their resources, grouping and using the data for problem solution in our country.

Widespread Doublecortin Expression in the Cerebral Cortex of the Octodon degus

It has been demonstrated that in adulthood rodents show newly born neurons in the subgranular layer (SGL) of the dentate gyrus (DG), and in the subventricular zone (SVZ). The neurons generated in the SVZ migrate through the rostral migratory stream (RMS) to the olfactory bulb. One of the markers of newly generated neurons is doublecortin (DCX). The degu similarly shows significant numbers of DCX-labeled neurons in the SGL, SVZ, and RMS. Further, most of the nuclei of these DCX-expressing neurons are also labeled by proliferating nuclear antigen (PCNA) and Ki67. Finally, whereas in rats and mice DCX-labeled neurons are predominantly present in the SGL and SVZ, with only a few DCX neurons present in piriform cortex, the degu also shows significant numbers of DCX expressing neurons in areas outside of SVZ, DG, and PC. Many areas of neocortex in degu demonstrate DCX-labeled neurons in layer II, and most of these neurons are found in the limbic cortices. The DCX-labeled cells do not stain with NeuN, indicating they are immature neurons.

Non-Conventional Migration: An Evolving Pattern in South Asia

The circumstances prevailing in South Asia (SA) have led to a plateauing migration stream that has resulted in several categories of migrants. The underlying factors driving migration have been identical in all the countries of SA. In recent years, however, poverty, conflicts, political and religious persecution, natural disasters and climate change have emerged as the most prominent drivers. External migration flow from SA has more than doubled between 2000 and 2015. This is a dynamic region, with millions (over 38m in 2017) of people crossing borders, both intra-regionally and extra-regionally. In recent years, wealthy citizens from SA have begun to move out of their countries with the intention of settling down elsewhere. This tendency has raised concerns among the policy makers because they create the grounds for reverse remittance flows. This research is meant to identify and contribute to the discourse of a new category of migrants (non-conventional migration) who are different from those in the conventional migration stream that included economic and forced migration. This research has crucial policy implications for both origin and destination countries.

The postcolonial migration state

The evolution of migration policymaking across the Global South is of growing interest to International Relations. Yet, the impact of colonial and imperial legacies on states’ migration management regimes outside Europe and North America remains under-theorised. How does postcolonial state formation shape policies of cross-border mobility management in the Global South? By bringing James F. Hollifield’s framework of the contemporary ‘migration state’ in conversation with critical scholarship on postcolonialism, we identify the existence of a ‘postcolonial paradox,’ namely two sets of tensions faced by newly independent states of the Global South: first, the need to construct a modern sovereign nation-state with a well-defined national identity contrasts with weak institutional capacity to do so; second, territorial realities of sovereignty conflict with the imperatives of nation-building seeking to establish exclusive citizenship norms towards populations residing both inside and outside the boundaries of the postcolonial state. We argue that the use of cross-border mobility control policies to reconcile such tensions transforms the ‘postcolonial state’ into the ‘postcolonial migration state,’ which shows distinct continuities with pre-independence practices. In fact, postcolonial migration states reproduce colonial-era tropes via the surveillance and control of segmented migration streams that redistribute labour for the global economy. We demonstrate this via a comparative study of post-independence migration management in India and Egypt, which also aims to merge a problematic regional divide between scholarship on the Middle East and South Asia. We urge further critical interventions on the international politics of migration that prioritise interregional perspectives from the broader Global South.

Telling Our Stories: Resilience during Resettlement for African Skilled Migrants in Australia.

Background: Emigration to Australia by people from Africa has grown steadily in the past two decades, with skilled migration an increasingly significant component of migration streams. Challenges to resettlement in Australia by African migrants have been identified, including difficulties securing employment, experiences of racism, discrimination and social isolation. These challenges can negatively impact resettlement outcomes, including health and wellbeing. There has been limited research that has examined protective and resilience factors that help highly skilled African migrants mitigate the aforementioned challenges in Australia. This paper discusses how individual and community resilience factors supported successful resettlement Africans in Australia. The paper is contextualised within a larger study which sought to investigate how belonging and identity inform Afrodiasporic experiences of Africans in Australia. Methods: A qualitative inquiry was conducted with twenty-seven (n = 27) skilled African migrants based in South Australia, using face-to-face semi-structured interviews. Participants were not directly questioned about ‘resilience,’ but were encouraged to reflect critically on how they navigated the transition to living in Australia, and to identify factors that facilitated a successful resettlement. Results: The study findings revealed a mixture of settlement experiences for participants. Resettlement challenges were observed as barriers to fully meeting expectations of emigration. However, there were significant protective factors reported that supported resilience, including participants’ capacities for excellence and willingness to work hard; the social capital vested in community and family support networks; and African religious and cultural values and traditions. Many participants emphasised their pride in their contributions to Australian society as well as their desire to contribute to changing narratives of what it means to be African in Australia. Conclusions: The findings demonstrate that despite challenges, skilled African migrants’ resilience, ambition and determination were significant enablers to a healthy resettlement in Australia, contributing effectively to social, economic and cultural expectations, and subsequently meeting most of their own migration intentions. These findings suggest that resilience factors identified in the study are key elements of integration.

The influence of maternal migration on child vaccination in Kenya: An inverse probability of treatment-weighted analysis

ObjectivesKenya has substantially improved child mortality between 1990 and 2019, with under-5 mortality decreasing from 104 to 43 deaths per 1000 live births. However, only two-thirds of Kenyan children receive all recommended vaccines by 1 year, making it essential to identify undervaccinated subpopulations. Internal migrants are a potentially vulnerable group at risk of decreased access to healthcare. This analysis explored how maternal migration within Kenya influences childhood vaccination. MethodsData were from the 2014 Kenya Demographic and Health Survey, a nationally representative cross-sectional survey. Logistic regressions assessed relationships between maternal migration and full and up-to-date child vaccination using inverse probability of treatment weighting. Two exposure variables were examined: migration status and stream (e.g. rural-urban). Multiple imputation was used to impute up-to-date status for children without vaccination cards to reduce selection bias. ResultsAfter accounting for selection and confounding biases, all relationships between migration status and migration stream and full and up-to-date vaccination became statistically insignificant. ConclusionsNull findings indicate that, in Kenya, characteristics enabling migration, rather than the process of migration itself, drive differential vaccination behavior between migrants and non-migrants. This finding is an important deviation from previous literature, which did not rigorously address important biases.

Proliferative Capacity of Adult Mouse Brain.

We studied cell proliferation in the postnatal mouse brain between the ages of 2 and 30 months and identified four compartments with different densities of proliferating cells. The first identified compartment corresponds to the postnatal pallial neurogenic (PPN) zone in the telencephalon; the second to the subpallial postnatal neurogenic (SPPN) zone in the telencephalon; the third to the white matter bundles in the telencephalon; and the fourth to all brain parts outside of the other three compartments. We estimated that about 3.4 million new cells, including 0.8 million in the subgranular zone (SGZ) in the hippocampus, are produced in the PPN zone. About 21 million new cells, including 10 million in the subependymal zone (SEZ) in the lateral walls of the lateral ventricle and 2.7 million in the rostral migratory stream (RMS), are produced in the SPPN zone. The third and fourth compartments together produced about 31 million new cells. The analysis of cell proliferation in neurogenic zones shows that postnatal neurogenesis is the direct continuation of developmental neurogenesis in the telencephalon and that adult neurogenesis has characteristics of the late developmental process. As a developmental process, adult neurogenesis supports only compensatory regeneration, which is very inefficient.

This Week in The Journal

Stéphane Bugeon, Clara Haubold, Alexandre Ryzynski, Harold Cremer, and Jean-Claude Platel (see pages [2630–2644][1]) Neural progenitors are generated in the rodent subventricular zone (SVZ) throughout adulthood. These progenitors travel tangentially through the rostral migratory stream until

Mobility and Urban Space in Early Modern Europe: An Introduction

Abstract Early modernists have explored a range of mobile practices taking place in cities: from religious and civic rituals to the multisensory experience of traversing streets and squares. Research has also shown the pivotal role played by cities as hubs where people came and went, ideas circulated, and goods passed through. Yet mobility did not just “take place” in cities. In presenting a new collection of articles on the subject, this paper suggests that urban spaces were more than just a stage for the streams of trade and migration. Rather, mobility had a transformative effect on cities: it assigned new meaning to urban locations, altered the ways in which space was ordered, and often refashioned the built environment itself. In addition, the paper argues that the relationship between movement and urban spaces was reciprocal: by channelling the flow of people through spaces of control and reception, cities shaped mobility as much as mobility shaped cities.

Does air pollution influence internal migration? An empirical investigation on Italian provinces

This research analyzes the role that air pollution plays, controlling for other socio-economic factors, in the movement of the population among Italian provinces. In spite of the increased prominence of environmental degradation in the public policy debate, empirical evidence on the effects of air quality on the attraction or retention of people is still limited in Italy. This study aims at partly filling this gap. Specific attention is paid to the environmental risks presented in provinces contaminated by air pollution. We investigate whether population moves away from provinces with higher levels of air pollution emissions toward those characterized by lower levels, net of the other contextual factors associated with migration streams. While many factors can come into play on mobility decisions, it is suggested that the increased concerns with environmental risks may be influential in shaping internal migration choices. We discuss the implications of our findings for future policy options.

Quail-chick grafting experiments corroborate that Tbr1-positive eminential prethalamic neurons migrate along three streams into hypothalamus, subpallium and septocommissural areas

The prethalamic eminence (PThE), a diencephalic caudal neighbor of the telencephalon and alar hypothalamus, is frequently described in mammals and birds as a transient embryonic structure, undetectable in the adult brain. Based on descriptive developmental analysis of Tbr1 gene brain expression in chick embryos, we previously reported that three migratory cellular streams exit the PThE rostralward, targeting multiple sites in the hypothalamus, subpallium and septocommissural area, where eminential cells form distinct nuclei or disperse populations. These conclusions needed experimental corroboration. In this work, we used the homotopic quail-chick chimeric grafting procedure at stages HH10/HH11 to demonstrate by fate-mapping the three predicted tangential migration streams. Some chimeric brains were processed for Tbr1 in situ hybridization, for correlation with our previous approach. Evidence supporting all three postulated migration streams is presented. The results suggested a slight heterochrony among the juxtapeduncular (first), the peripeduncular (next), and the eminentio-septal (last) streams, each of which followed differential routes. A possible effect of such heterochrony on the differential selection of medial to lateral habenular hodologic targets by the migrated neurons is discussed.

Intrinsic Neuronal Activity during Migration Controls the Recruitment of Specific Interneuron Subtypes in the Postnatal Mouse Olfactory Bulb.

Neuronal activity has been identified as a key regulator of neuronal network development, but the impact of activity on migration and terminal positioning of interneuron subtypes is poorly understood. The absence of early subpopulation markers and the presence of intermingled migratory and postmigratory neurons make the developing cerebral cortex a difficult model to answer these questions. Postnatal neurogenesis in the subventricular zone (SVZ) offers a more accessible and compartmentalized model. Neural stem cells regionalized along the border of the lateral ventricle produce two main subtypes of neural progenitors, granule cells and periglomerular neurons that migrate tangentially in the rostral migratory stream (RMS) before migrating radially in the olfactory bulb (OB) layers. Here, we used targeted postnatal electroporation to compare the migration of these two populations in male and female mice. We do not observe any obvious differences regarding the mode of tangential or radial migration between these two subtypes. However, we find a striking increase of intrinsic calcium activity in granule cell precursors (GC-Ps) when they switch from tangential to radial migration. By decreasing neuronal excitability in GC-Ps, we find that neuronal activity has little effect on migration but is required for normal positioning and survival of GC-Ps in the OB layers. Strikingly, decreasing activity of periglomerular neuron precursors (PGN-Ps) did not impact their positioning or survival. Altogether these findings suggest that neuronal excitability plays a subtype specific role during the late stage of migration of postnatally born OB interneurons.SIGNIFICANCE STATEMENT While neuronal activity is a critical factor regulating different aspects of neurogenesis, it has been challenging to study its role during the migration of different neuronal subpopulations. Here, we use postnatal targeted electroporation to label and manipulate the two main olfactory bulb (OB) interneuron subpopulations during their migration: granule cell and periglomerular neuron precursors (PGN-Ps). We find a very striking increase of calcium activity only in granule cell precursors (GC-Ps) when they switch from tangential to radial migration. Interestingly, blocking activity in GC-Ps affected mainly their positioning and survival while PGN-Ps were not affected. These results suggest that neuronal activity is required specifically for the recruitment of GC-Ps in the OB layers.

Sim1-expressing cells illuminate the origin and course of migration of the nucleus of the lateral olfactory tract in the mouse amygdala

We focus this report on the nucleus of the lateral olfactory tract (NLOT), a superficial amygdalar nucleus receiving olfactory input. Mixed with its Tbr1-expressing layer 2 pyramidal cell population (NLOT2), there are Sim1-expressing cells whose embryonic origin and mode of arrival remain unclear. We examined this population with Sim1-ISH and a Sim1-tauLacZ mouse line. An alar hypothalamic origin is apparent at the paraventricular area, which expresses Sim1 precociously. This progenitor area shows at E10.5 a Sim1-expressing dorsal prolongation that crosses the telencephalic stalk and follows the terminal sulcus, reaching the caudomedial end of the pallial amygdala. We conceive this Sim1-expressing hypothalamo-amygdalar corridor (HyA) as an evaginated part of the hypothalamic paraventricular area, which participates in the production of Sim1-expressing cells. From E13.5 onwards, Sim1-expressing cells migrated via the HyA penetrate the posterior pallial amygdalar radial unit and associate therein to the incipient Tbr1-expressing migration stream which swings medially past the amygdalar anterior basolateral nucleus (E15.5), crosses the pallio-subpallial boundary (E16.5), and forms the NLOT2 within the anterior amygdala by E17.5. We conclude that the Tbr1-expressing NLOT2 cells arise strictly within the posterior pallial amygdalar unit, involving a variety of required gene functions we discuss. Our results are consistent with the experimental data on NLOT2 origin reported by Remedios et al. (Nat Neurosci 10:1141–1150, 2007), but we disagree on their implication in this process of the dorsal pallium, observed to be distant from the amygdala.

MIGRACJE WEWNĘTRZNE NA POBYT STAŁY W MAKROREGIONIE POŁUDNIOWO-ZACHODNIM W LATACH 2002–2017

Głównym celem opracowania koncentruje się będzie na rozpoznaniu wartości interpretacyjnej i wnioskowej migracji wewnętrznych na pobyt stały z uwzględnieniem ich kierunku. Analizowane dane obejmują okres 2002–2017 a pochodzą z internetowej bazy danych Demografia GUS. W opracowaniu dokonano rozpoznania zjawiska migracji wychodząc od ujęcia ogółem, przez ujęcie klasyczne, ostatecznie do ukazania wielkości i kierunków przemieszczeń. Ukazując wielkość i kierunki przemieszczeń posługiwano się sumaryczną, wartością migracji w badanym okresie. Podejście to określono mianem „agregatowego”. Pozwoliło ono na identyfikację zlewni i obszarów atrakcyjności migracyjnej. Jakkolwiek obszary te są silnie zbliżone co do ich rozciągłości przestrzennej to zróżnicowane ze względu na wielkość i zasięg głównych strumieni migracji. Migracje wewnętrzne na pobyt stały jawią się jako dobry identyfikator urbanizacji stref podmiejskich i kształtowania powiązań funkcjonalnych miasto–obszar wiejski–miasto.

Intrinsic Mechanisms Regulating Neuronal Migration in the Postnatal Brain.

Neuronal migration is a fundamental brain development process that allows cells to move from their birthplaces to their sites of integration. Although neuronal migration largely ceases during embryonic and early postnatal development, neuroblasts continue to be produced and to migrate to a few regions of the adult brain such as the dentate gyrus and the subventricular zone (SVZ). In the SVZ, a large number of neuroblasts migrate into the olfactory bulb (OB) along the rostral migratory stream (RMS). Neuroblasts migrate in chains in a tightly organized micro-environment composed of astrocytes that ensheath the chains of neuroblasts and regulate their migration; the blood vessels that are used by neuroblasts as a physical scaffold and a source of molecular factors; and axons that modulate neuronal migration. In addition to diverse sets of extrinsic micro-environmental cues, long-distance neuronal migration involves a number of intrinsic mechanisms, including membrane and cytoskeleton remodeling, Ca2+ signaling, mitochondria dynamics, energy consumption, and autophagy. All these mechanisms are required to cope with the different micro-environment signals and maintain cellular homeostasis in order to sustain the proper dynamics of migrating neuroblasts and their faithful arrival in the target regions. Neuroblasts in the postnatal brain not only migrate into the OB but may also deviate from their normal path to migrate to a site of injury induced by a stroke or by certain neurodegenerative disorders. In this review, we will focus on the intrinsic mechanisms that regulate long-distance neuroblast migration in the adult brain and on how these pathways may be modulated to control the recruitment of neuroblasts to damaged/diseased brain areas.

East Polynesian Subgrouping and Homeland Implications Within the Northern Outlier–East Polynesian Hypothesis

This article is a continuation of investigations into the origin of East Polynesian languages in the Central Northern Outliers (Luangiua, Nukumanu, Takuu, Nukeria), rather than in Central Western Polynesia. Proto-East Polynesian is proposed as developing in an area bounded by the Phoenix, Line, and Marquesas Islands. Two major dialects of Proto-East Polynesian are reconstructed. Proto-East Polynesian Distal and Proto-East Polynesian Proximal. Proto-East Polynesian Distal is proposed as spoken distant from the Outliers in the Marquesas. East Polynesian Distal splits into Marquesan and Far Eastern Polynesian. Proto-Far Eastern Polynesia is proposed as spoken in Mangareva after settlement there from the Marquesas. Proto-Far Eastern Polynesian then splits into Mangarevan and Rapa Nui. The other major dialect of Proto-East Polynesian is Proto-East Polynesian Proximal, "proximal" because it is proposed as spoken in an area located closer to the Outliers than that where Proto-East Polynesian Distal was spoken. Proto East Polynesian Proximal is reconstructed with two subdialects, a Northern subdialect, Proto-East Polynesian Proximal (Northern), ancestral to Hawaiian, and a Southern subdialect Proto-East Polynesian Proximal (Southern), ancestral to the remaining East Polynesian languages. Proto-East Polynesian and later Proto-East Polynesian Proximal were likely initially spoken within the bounds of the Phoenix and Line Islands. The proposal for a large west to east Proto-East Polynesian homeland and the division of Proto-East Polynesian into three communalects that provided three migration streams out of that homeland contests the most commonly accepted ideas regarding the settlement of East Polynesia.

Nasal administration of mitochondria reverses chemotherapy-induced cognitive deficits.

Up to seventy-five percent of patients treated for cancer suffer from cognitive deficits which can persist for months to decades, severely impairing quality of life. Although the number of cancer survivors is increasing tremendously, no efficacious interventions exist. Cisplatin, most commonly employed for solid tumors, leads to cognitive impairment including deficits in memory and executive functioning. We recently proposed deficient neuronal mitochondrial function as its underlying mechanism. We hypothesized nasal administration of mitochondria isolated from human mesenchymal stem cells to mice, can reverse cisplatin-induced cognitive deficits.Methods: Puzzle box, novel object place recognition and Y-maze tests were used to assess the cognitive function of mice. Immunofluorescence and high-resolution confocal microscopy were employed to trace the nasally delivered mitochondria and evaluate their effect on synaptic loss. Black Gold II immunostaining was used to determine myelin integrity. Transmission electron microscopy helped determine mitochondrial and membrane integrity of brain synaptosomes. RNA-sequencing was performed to analyse the hippocampal transcriptome.Results: Two nasal administrations of mitochondria isolated from human mesenchymal stem cells to mice, restored executive functioning, working and spatial memory. Confocal imaging revealed nasally delivered mitochondria rapidly arrived in the meninges where they were readily internalized by macrophages. The administered mitochondria also accessed the rostral migratory stream and various other brain regions including the hippocampus where they colocalized with GFAP+ cells. The restoration of cognitive function was associated with structural repair of myelin in the cingulate cortex and synaptic loss in the hippocampus. Nasal mitochondrial donation also reversed the underlying synaptosomal mitochondrial defects. Moreover, transcriptome analysis by RNA-sequencing showed reversal of cisplatin-induced changes in the expression of about seven hundred genes in the hippocampus. Pathway analysis identified Nrf2-mediated response as the top canonical pathway.Conclusion: Our results provide key evidence on the therapeutic potential of isolated mitochondria - restoring both brain structure and function, their capability to enter brain meninges and parenchyma upon nasal delivery and undergo rapid cellular internalization and alter the hippocampal transcriptome. Our data identify nasal administration of mitochondria as an effective strategy for reversing chemotherapy-induced cognitive deficits and restoring brain health, providing promise for the growing population of both adult and pediatric cancer survivors.

The Regulation, Division, and Multiplication of Emigrant Labor: The Border between Land and Sea in Colonial India, 1834–1922

In this article, I argue the significance of the border between land and sea for the regulation of labor migration. I identify an early sense of this border in the East India Company's efforts to prohibit the trafficking of slaves overseas by foreign powers. I focus on a shift in the imaginary of the border with the advent of the indentured labor system. New permits, passes, and registration procedures were implemented to materialize the voluntariness of emigration for indentured laborers. Through an examination of Indian emigration legislation, I trace the continuous recalibration of the border through the differential inclusion of new occupational groups and labor migration streams under the umbrella of state regulation. I reevaluate the campaign for the abolition of indentured labor as a further recalibration of the border between land and sea that distinguished discrete rights of mobility for laboring subjects divided and multiplied by the category of skill.

A profusion of neural stem cells in the brain of the spiny mouse, Acomys cahirinus.

The vast majority of neural stem cell studies have been conducted on the brains of mice and rats, the classical model rodent. Non-model organisms may, however, give us some important insights into how to increase neural stem cell numbers for regenerative purposes and with this in mind we have characterized these cells in the brain of the spiny mouse, Acomys cahirinus. This unique mammal is highly regenerative and damaged tissue does not scar or fibrose. We find that there are more than three times as many stem cells in the SVZ and more than 3 times as many proliferating cells compared to the CD-1 outbred strain of lab mouse. These additional cells create thick stem cell regions in the wall of the SVZ and very obvious columns of cells moving into the rostral migratory stream. In the dentate gyrus, there are more than 10 times as many cells proliferating in the sub-granular layer and twice the number of doublecortin expressing neuroblasts. A preliminary analysis of some stem cell niche genes has identified Sox2, Notch1, Shh, and Noggin as up-regulated in the SVZ of Acomys and Bmp2 as being down-regulated. The highly increased neural stem cell numbers in Acomys may endow this animal with increased regenerative properties in the brain or improved physiological performance important for its survival.