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The relative roles of tectonics and climate change in global and regional desertification are not well constrained. Previous studies have emphasized the role played by climate change as a dominant cause of southeastern (SE) Asia desertification during the mid-Late Cretaceous. The effect of early uplift of the Tibetan Plateau prior to the collision between Eurasia and India on regional desertification remains poorly understood. We present a comprehensive set of provenance data on two aeolian sequences deposited in the Simao Basin and Khorat Plateau desert environments adjacent to southeast Tibet. Our provenance results suggest that the aeolian sandstones of the Pashahe Formation in the Simao Basin were largely recycled from exposed sedimentary rocks of the Songpan-Garze terrane, Southern Qiangtang terranes, and northern Yangtze Block with minor contributions from the magmatic rocks of the Tengchong and Southern Qiangtang terranes. Combined with other evidence, provenance results indicate the source areas started to grow and to be rapidly unroofed and determined the birth of the transcontinental southerly flowing paleo-river, which carried the sand to be stored. In contrast, the Phu Thok aeolian sandstones in the Khorat Plateau were predominantly sourced from the exposed Sibumasu igneous rocks together with recycled detritus in the Sukhothai Arc terrane, which was possibly transported by a local river. Hence, our thesis is that elevated topography caused by the closure of the Bangong-Nujiang Mesotethys profoundly affected the atmospheric circulation and drainage development, leading to mid-Late Cretaceous desertification across SE Asia.

Two types of potash ores were sampled from the Mengyejing potash deposit (the MPD) which is the only ancient potash deposit ever found in China. Geochemical analyses, including Br, K, Mg and some heavy metals, were performed on those samples. The relatively consistent Br contents (141.42 to 763.67 ppm) in both bedded potash and veined potash ores show that the potash-forming brine was likely derived from seawater. K contents and Br/Cl ratios of the veined potash ores are relatively high in contrast to bedded potash ores. The K/Br ratios of veined potash ores exhibit a positive correlation with Br contents, which is opposite to that of the bedded potash ore of the MPD and potassium-salts from the evaporation of modern seawater. The contents of heavy metals in veined potash ores are much higher than those of bedded potash ores in the MPD and potash in other evaporite basins of the world. Sr and S isotopic compositions of these two types of potash ores suggest that the brines for precipitating veined potash were formed by mixing of connate waters (seawater or/and continental freshwater) and hydrothermal fluids. The geochemical and petrological characteristics of the veined potash ores indicate that the brine for forming veined potash orebodies caused by dissolution of previous bedded potash orebodies by hydrothermal fluids. The veined potash orebodies were formed through a cooling process by which sylvite precipitated first prior to halite.

The surface uplift of the Tibetan Plateau (TP) and its geomorphology evolution has triggered aridification of Asia's interior and drainage development at the eastern margin of the plateau. However, how the pre-Cenozoic early growth histories of the TP impact the drainage system and climate is poorly constrained. The Late Mesozoic Lacustrine evaporite-bearing basins on the eastern margin of the TP record significant information on the uplift of the source terranes, source-to-sink system development and climate change. In this study, we presented detrital zircon U–Pb ages from the Upper Cretaceous Yunlong Formation in the Lanping Basin, as well as Hf isotopic, petrographic, direct statistical, and multidimensional scaling analyses, and use them to characterize the provenance and reconstruct the drainage system. All of the samples have five major age peaks at 200–290 Ma, 400–490 Ma, 750–1000 Ma, 1750–1950 Ma, and 2400–2600 Ma with mostly negative ɛHf(t) values (81%). We infer the sediments are primarily derived from recycled sediments of the Songpan-Garze terrane, and partly from the Sichuan Basin and the Southern Qiangtang terrane, as well as the exposed magmatic rocks of the Yidun Arc and Songpan-Garze terrane. The provenance features of the contemporaneous sediments from the Sichuan, Xichang, Chuxiong, and Simao basins indicate a complex hierarchical drainage pattern on the eastern margin of the TP during the Late Cretaceous. The hierarchical drainage system exhibits a complete gradational cycle of lake-basin types from overfilled freshwater Sichuan Basin through balanced fill saline Xichang Basin and underfilled hypersaline Chuxiong, Lanping, Simao, and Khorat Plateau basins from proximal to distal. The early growth of the TP primarily controlled the drainage and lake-basin evolution by not only causing the uplift and exhumation of the source areas and providing large amounts of clastic material to the proximal sub-drainage areas but also intensifying the aridity and deposition of evaporites.

Potash deposits are common in the Mesozoic-Cenozoic Tethyan domain, which features the giant potash deposits in the Late Jurassic Central Asian Basin and the Late Cretaceous Khorat Basin of Thailand-Laos. Widespread evaporitic sequences from these intervals have been found in some marine and transitional basins within the Chinese continental blocks, such as the Yangtze, Simao and Tarim blocks, in which, only one small-scale potash deposit had been found in the Late Cretaceous Simao Basin. These evaporites are commonly characterized by depositional cycles that are more frequent than those of other potash basins around the world. It remains debated whether large or giant potash deposits could be formed in Chinese blocks of Tethyan domain, and if so, what mechanism was responsible for the potash formation. To address these issues, we comprehensively review the Meso-Cenozoic drift history and collision dynamics of these Chinese blocks and summarize the formation mechanism, depositional characteristics, and paleoclimate of the evaporite basins in these blocks. These blocks drifted from the Southern Hemisphere and collided and welded together in the beginning of the late Permian in the Northern Hemisphere. The collisions often commenced in the east and gradually spread to the west of these blocks, resulting in: (1) westward seawater retreat; (2) differential topographic uplift with high topography in the east and low topography in the west and (3) increasingly closed depositional environments in these basins. In addition, these collisions often exerted nearly N-S-oriented principal compressive stress, which resulted in nearly E-W-oriented extension. These forces induced a series of faulted-bounded subsidence belts with N-S-striking extensional sub-basins arranged in an E-W-oriented chain in these blocks. In this chain-like sub-basins system, as sea level rose and seawater flowed from west to east, the western sub-basins proximal to the open sea would have precipitated calcium carbonates and calcium sulfates, resulting in a high degree of concentration by the time the brines reached the distal end, i.e. eastern sub-basins. Ultimately, potash minerals were commonly deposited in the easternmost sub-basins. Based on the above model of potash formation, we predict that potash deposits may be formed in certain sub-basins in the eastern part of these basins in Chinese Tethyan blocks, which maybe lay a theoretical foundation for China’s future exploration of potash deposits.

Evaporites and carbonates intercalated with volcanic beds are distributed in the Jialingjiang and Leikoupo Formations straddling the boundary of the Lower and Middle Triassic in the Sichuan Basin. ...

Purpose As a promising photodynamic therapy (PDT) agent, Al(III) phthalocyanine chloride tetrasulfonic acid (AlPcS4) provides deep penetration into tissue, high quantum yields, good photostability, and low photobleaching. However, its low delivery efficiency and high binding affinity to serum albumin cause its low penetration into cancer cells, further limiting its PDT effect on gastric cancer. In order to improve AlPcS4/PDT effect, the AlPcS4 delivery sys tems with different drug carriers were synthesized and investigated. Materials and methods Gold nanorods, cationic liposomes, and Pluronic® F127 nanomicellars were used to formulate the AlPcS4 delivery systems. The anticancer effect was evaluated by CCK-8 assay and colony formation assay. The delivery efficiency of AlPcS4 and the binding affinity to serum proteins were determined by fluorescence intensity assay. The apoptosis and necrosis ability, reactive oxygen species and singlet oxygen generation, mitochondrial transmembrane potential and ([Ca2+]i) concentration were further measured to evaluate the mechanism of cell death. Results The series of synthesized AlPcS4 delivery systems with different drug carriers improve the limited PDT effect in varying degrees. In contrast, AlPcS4 complex with gold nanorods has significant anticancer effects because gold nanorods are not only suitable for AlPcS4 delivery, but also exhibit enhanced singlet oxygen generation effect and photothermal effect to induce cell death directly. Moreover, AlPcS4 complex with cationic liposomes shows the potent inhibition effect because of its optimal AlPcS4 delivery efficiency and ability to block serum albumin. In addition, AlPcS4 complex with Pluronic F127 exhibits inferior PDT effect but presents lower cytotoxicity, slower dissociation rate, and longer retention time of incorporated drugs; thus, F127-AlPcS4 is used for prolonged gastric cancer therapy. Conclusion The described AlPcS4 drug delivery systems provide promising agents for gastric cancer therapy.

The Mengyejing potash deposit (MPD) is the first significant ancient potash deposit ever found in China, and it was considered to have formed during the middle to late Cretaceous. The 87 Sr/ 86 Sr ratios of potash bulk samples suggest that both bedded and veined potash orebodies of the MPD have been affected by igneous activity resulting from decompression melting of a metasomatically altered, depleted mantle from 16 Ma to present. The Rb-Sr isotopic systematics of the potash bulk samples define several apparent “isochrons” ranging from 0.609 ± 0.026 to 14.23 ± 0.63 Ma, with the maximum age being consistent with previous K-Ar ages of the K-bearing minerals from the MPD. Such isotopic signatures imply that the MPD may have been affected by multiple-stage fluid flow events since the mid-Miocene, consisting of hydrothermal fluids, continental fresh water, and/or hot spring water. It is very likely that the MPD is still affected by fluid flow-events in modern times. The mineral assemblage of halite + sylvite with minor amounts of carnallite was formed due to the recrystallization and diagenetic modification by hydrothermal fluids. Some characteristics of halite photomicrographs and inclusions and the lack of original halite chevron patterns are also supportive of the hypothesis that the deposit has undergone a diagenetic modification and dissolution–recrystallization processes.

Asian aridification during the Cenozoic was strongly related to moisture flux modulated by sea incursion and the retreat fluctuations of the proto-Paratethys Sea via the Westerlies. However, the extents of the sea incursions are poorly constrained, and there is a lack of sedimentary records beyond the Central Asian basins. The Middle to Late Cretaceous Simao Basin and the Khorat Plateau in Southeast Asia contain thick continental sequences of red beds, evaporites, and aeolian deposits, but whether the depositional environment of the evaporites was marine or continental has been hotly debated. In this study, we compiled multiple sedimentology proxies, biomarkers, element geochemistry, and isotopic geochemistry of the fine-grained sediments of the Mohan section in the Simao Basin. Sedimentological analyses show that this section is composed of subtidal flat fine-grained siliciclastic and carbonate rocks and supratidal flat conglomerates and evaporites. The paleosalinity proxies show that the B concentration and B/Ga and Srcorrected/Ba ratios range from 30.3 to 81.7 ppm, 2.4 to 5.0, and 0.05 to 0.60, respectively, which indicate brackish conditions. The two typical increases in these proxies are consistent with the stratigraphic horizons of the diagnostic marine biomarkers 24-n-propyl- and 24-iso-propylcholestanes, which suggests seawater recharge. The carbonate δ13C and δ18O values (−4.84‰ to −1.75‰ and −8.25‰ to −3.69‰, respectively) and the bulk δ13Corg values (−26.5‰ to −23.22‰) also indicate the influence of seawater. We propose that the seawater likely originated from the proto-Paratethys Sea during a marine incursion. We propose for the first time that the proto-Paratethys seawater incursions extended into the Simao Basin and the Khorat Plateau. These results provide a novel paleogeographic configuration for East Asia during the Middle to Late Cretaceous. The retreat of the proto-Paratethys Sea, the northeast Trade Winds, and the tectonic uplift dramatically decreased the moisture and intensified the extreme aridification in the Simao Basin and the Khorat Plateau.

The Muang Xai Basin, located in northern Laos, is associated with the Simao, Vientiane, and Khorat Basins. The paleogeographic link of these basins has not been investigated in great detail; thus, the investigation presented in this study is a comprehensive analysis of petrology, whole-rock geochemistry, and detrital zircon U–Pb chronology used to characterize the provenance of the Muang Xai Basin. Results suggest that the sedimentary source includes felsic rocks from an active continental margin or continental arc with minor amounts of recycled passive continental margin sediments. Sandstones of the Muang Xai Basin contain detrital zircons with varying U–Pb peak ages. The youngest age peak of all the zircons is 103 Ma, which limits the age of the Mesozoic strata to the Late Cretaceous. Detrital zircon U–Pb and trace element data, combined with geochemical result, reveal that the pre-Ordovician zircons were derived from recycled sediments of the Yangtze Block, which are originally sourced from the Qinling Orogenic belt. This provenance is shared with coeval sediments in the Simao and Khorat Basins, while magmatic rocks of the Ailaoshan, Truong Son Belt, and Lincang terrane are responsible for zircons of 416–466 and 219–308 Ma in age. Zircons of 101–110 and 149–175 Ma in age were sourced from magmatic rocks of the southwestern South China Block and northern Vietnam. These provenance results suggest that sediments flow into the Khorat red beds was likely from the Great Simao Basin and northern Vietnam, and not directly from the Yangtze Block.

The Mengyejing potash deposit is located in the southern port of the Simao Basin, Yunnan Province, and is hosted in mid-Cretaceous strata. The chemical compositions of fluid inclusions in halite crystals, collected from the level-610 adit in the deposit, were analysed by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The results show that the brine is of the Na-K-Mg-Ca-Cl type and has K concentrations that are distinctly higher than those of Mg and Ca, unlike normal brines associated with Cretaceous halite. The high K concentrations indicate that the degree of evaporation of the ancient Mengyejing saline lake was very high, reaching the sylvite deposition stage but rarely reaching the carnallite deposition stage. The trajectory of the H and O isotopic compositions of the brines in the halite-hosted fluid inclusions corresponds to intense evaporation, indicating that the net evaporation exceeded the net inflow of brines. These brine compositions in halite-hosted fluid inclusions were likely formed by the dissolution of previously deposited K-bearing minerals by fresh continental and/or seawater, forming a type of modified seawater, with deep hydrothermal fluids potentially supplying additional potassium. The basin likely experienced multiple seawater incursion, dissolution and redeposition events in a high-temperature environment with high evaporation rates.

The Cenozoic was a time of rapid change in the large river systems of the southeastern Tibetan Plateau. Many previous studies proposed a connection between the upper reaches of the Salween, Mekong, Jinsha (Upper Yangtze) Rivers and paleo-Red River which then flowed to the South China Sea. However, little is known about the pre-Cenozoic source-to-sink river pathways of the Tibetan Plateau. Using 848 detrital zircon U-Pb ages derived from the Lower Cretaceous samples located in the Vientiane Basin, combined with petrographic, statistical, and Multidimensional Scaling (MDS) analyses, we present a detailed history of the paleo-Mekong River. All samples can be divided into three groups based on their age distribution. Samples in Group 1 from the lower part of section show major peaks in the Wutai (2400–2600 Ma), Luliangian (1700–1900 Ma), Jinningian (750–1000 Ma), Indosinian (200–290 Ma), and Yanshanian (150–200 Ma) periods, and are mainly sourced from the Southern Qiangtang terrane. These samples bear no resemblance to modern river sands in the MDS diagram. As such, we infer that these samples represent a unique paleo-river course from the Southern Qiangtang terrane. Samples in Groups 2–3 at the middle and upper part of section yield age peaks at the Luliangian, Jinningian, Caledonian (400–490 Ma), Indosinian, and Yanshanian periods, and are sourced from the Sichuan Basin, Songpan-Garze and the Northern Qiangtang terranes, which have characteristics similar to those of the modern Mekong River and Jinsha River. In our paleo-drainage model, the upper reach of the paleo-Mekong River did not connect to the Upper Salween River and flow into the Red River during the early Early Cretaceous period, as has been proposed previously. In the late Early Cretaceous, the upper segment of the paleo-Mekong River, which drained from the Sichuan Basin and Songpan-Garze terrane, and the upper reach of the Jinsha River were tributaries of a single Mekong River before collecting in the Vientiane and Khorat Plateau basins. These provenance and drainage changes (or lack thereof) were driven by the collision between the Lhasa and Qiangtang terranes ~120 Ma and the subsequent uplift and denudation of the Northern Qiangtang and Songpan-Garze terranes.

The poor cell membrane penetration ability of photosensitizers resulted in the limited antitumor effect, thereby hampered their potential in clinical translation. The high toxic side effect and multidrug resistance of chemotherapeutic agents during in clinical chemical therapy should be resolved. Nanosystem integrated with photosensitizer and novel targeting chemotherapy agent may be an effective strategy for overcoming clinical or preclinical drawbacks of monotherapy and enhancing therapeutic effect. Therefore, a nanosized micelle F127 integrated with Apogossypolone (ApoG2) and Al(III) phthalocyanine chloride tetrasulfonic acid (AlPcS4) (referred as F127-ApoG2@AlPcS4) was synthesized to induce the cell death quickly for reducing the risk of resistance and enhancing gastric cancer therapeutic efficiency by combining AlPcS4/photodynamic therapy and ApoG2/chemotherapy. Hydrophobic of ApoG2 and hydrophilic of AlPcS4 self-assembled into this micelle to formation of core-shell structure based on the amphiphilic character of F127 micelle. The reactive oxygen species-dependent mitochondria membrane permeability was improved effectively because of reactive oxygen species generation of ApoG2, thereby resulting in a considerable amount of AlPcS4 and ApoG2 entering the mitochondrial. The AlPcS4 binding site was altered from the cytoplasm to the cell nucleus at higher concentration because of the existence of ApoG2. With irradiation, ApoG2 and AlPcS4 showed effective synergistic anti-tumor effect through inducing apoptosis due to singlet oxygen production regulated mainly by AlPcS4, reactive oxygen species accumulation and calcium overload regulated mainly by ApoG2. Intranuclear AlPcS4 caused cell death through necrosis. The apoptosis induced by AlPcS4 was earlier than ApoG2. In summary, F127-ApoG2@AlPcS4 quickly induced a long-lasting apoptosis that led to cell death, which could be a promising nanosized reagent for gastric cancer therapy based on chemo-photodynamic combined therapy.

Limited cellular delivery and internalization efficiency of Al(III) phthalocyanine chloride tetrasulfonic acid (AlPcS4) induce poor penetration ability in cells and a slight photodynamic therapy (PDT) effect on gastric cancer. The combination treatment of AlPcS4/PDT with low-dose chemotherapeutic agents may provide a promising treatment strategy to increase the weak delivery efficiency of AlPcS4, reducing the dose of chemical agents without reducing efficacy, and improving apoptosis-inducing abilities, thereby increasing the antitumor effects and decreasing the noxious side effects on gastric cancer. We investigated and compared the synergistic antitumor growth effect on gastric cancer cells by combining AlPcS4/PDT treatment with different low-dose chemotherapeutic agents, namely, 5-fluorouracil (5-FU), doxorubicin (DOX), cisplatin (CDDP), mitomycin C (MMC), and vincristine (VCR). The inhibitory effect was increased in treatments that combined AlPcS4/PDT with all the aforementioned low-dose chemotherapeutic agents, to a different extent. An evident synergistic effect was obtained in the combination treatment of AlPcS4/PDT with low-dose 5-FU, DOX, and MMC by increasing AlPcS4 intracellular uptake ability, improving apoptosis-inducing abilities, and prolonging apoptosis-inducing time. The low-dose chemotherapeutic agents prolonged the apoptosis-inducing period of AlPcS4/PDT, and AlPcS4/PDT quickly improved apoptosis-inducing abilities of chemotherapy even at low doses. Generally, the combination treatment of AlPcS4/PDT with low-dose chemotherapeutic agents had significant antitumor growth effects in addition to a low dark-cytotoxicity effect on gastric cancer, thereby representing an effective and feasible therapy method for gastric cancer.

High temperatures and arid climates were extensive throughout the Tethyan domain during the mid-Cretaceous, and thus greatest volumes of evaporites were deposited and widely distributed. The Mengyejing Formation, which contains the only pre-Quaternary potash salt deposit in China, is thought to be genetically related to the Late Cretaceous Maha Sarakham Formation in the Khorat Basin. The age of the Mengyejing Formation has been a subject of debate and controversy and was previously interpreted as Paleocene in age mainly based on a few palynology and ostracoda fossils. In this paper, we report U–Pb sensitive high-resolution ion microprobe (SHRIMP) ages between 100 Ma to 110 Ma for the first time from the tuff beds interbedded with gypsum units and siltstones from the upper part of the Mengyejing Formation in the Simao Basin, southwestern Yunnan. This age indicates that the age of the Mengyejing Formation is likely Albian to Cenomanian providing precise geochronological constraint for the age of the Mengyejing Formation in the Simao Basin, which is consistent with the age of the Maha Sarakham Formation. Combined with marine origin of δ 34 S values for gypsum units in the Mengyejing Formation, the ages indicate that marine incursions from the Neo-Tethyan Ocean in the mid-Cretaceous were caused by global high sea level. However, the stratigraphic succession of the Mengyejing Formation cannot be well correlated with those of the Maha Sarakham Formation caused by marine incursion and tectonic inversion in the mid-Cretaceous.

During mammalian cerebral corticogenesis, progenitor cells become progressively restricted in the types of neurons they can produce. The molecular mechanism that determines earlier versus later born neuron fate is unknown. We demonstrate here that the generation of the earliest born neurons, the Cajal-Retzius cells, is suppressed by the telencephalic transcription factor Foxg1. In Foxg1 null mutants, we observed an excess of Cajal-Retzius neuron production in the cortex. By conditionally inactivating Foxg1 in cortical progenitors that normally produce deep-layer cortical neurons, we demonstrate that Foxg1 is constitutively required to suppress Cajal-Retzius cell fate. Hence, the competence to generate the earliest born neurons during later cortical development is actively suppressed but not lost.

The winged helix gene Brain factor-1 (BF1) has a pleiotropic role in the development of the cerebral hemispheres of the brain. Mice lacking BF1 have defects in the morphogenesis of the structures of the dorsal telencephalon (e.g., neocortex) and the ventral telencephalon (e.g., the basal ganglia). This study focuses on the functions of BF1 in the dorsal telencephalon. We showed previously that telencephalic progenitor cells lacking BF1 differentiate into neurons prematurely. Here, we demonstrate that the loss of BF1 also results in an early lengthening of the cell cycle in neocortical progenitors. To investigate the mechanisms by which BF1 regulates progenitor cell proliferation and differentiation in the developing brain, we have replaced the endogenous BF1 protein with a DNA binding defective form of BF1 in mice, BF1(NHAA). The BF1(NHAA) protein restores the growth of the dorsal telencephalon, by improving the proliferation of progenitor cells. However, the BF1(NHAA) protein does not correct the early neuronal differentiation associated with the loss of BF1. In contrast, replacement of endogenous BF1 with wild-type BF1 corrects the defects in both the proliferation and differentiation of neocortical progenitors. These results demonstrate that BF1 controls progenitor cell proliferation and differentiation in the neocortex through distinct DNA binding-independent and binding-dependent mechanisms.

FoxG1 (formerly BF-1) encodes a transcription factor that regulates neurogenesis in the embryonic telencephalon. The current study suggests that FoxG1 also regulates neurogenesis in the postnatal hippocampus. FoxG1 continues to be strongly expressed in areas of known postnatal neurogenesis, including the subventricular zone of the lateral ventricle and the dentate gyrus (DG) of the hippocampus. Remarkably, FoxG1+/- mice have a 60% decrease in the total number of hippocampal dentate granule cells that is related to a loss of DG neurogenesis. Comparison of acute and chronic BrdU labeling, and PSA-NCAM staining suggests that the stage at which this loss of neurogenesis occurs progresses with age. Juvenile mice FoxG1+/- primarily show failed apparent survival of postnatally born DG neurons, whereas adult FoxG1+/- mice also show impairment of proliferation and initial DG neuron differentiation. Consistent with this process predominantly affecting postnatal hippocampal neurogenesis, BrdU pulses at embryonic days 16, 17, and 18 labels a higher percentage of DG cells in 6-week-old FoxG1+/- mice than in littermate controls. In contrast to the marked effect of FoxG1 haploinsufficiency on postnatal hippocampal neurogenesis, postnatal neurogenesis of olfactory bulb interneurons is grossly unaffected. Behaviorally, FoxG1+/- mice show hyperlocomotion and impaired habituation in the open field, and a severe deficit in contextual fear conditioning that are suggestive of impaired hippocampal function. Although mechanistic connections between FoxG1 haploinsufficiency and either failed postnatal DG neurogenesis or the behavioral deficits remain to be elucidated, these results present a new model system for impaired postnatal neurogenesis in the DG of adult mice.

FoxO Forkhead transcription factors are shown here to act as signal transducers at the confluence of Smad, PI3K, and FoxG1 pathways. Smad proteins activated by TGF-β form a complex with FoxO proteins to turn on the growth inhibitory gene p21Cip1. This process is negatively controlled by the PI3K pathway, a known inhibitor of FoxO localization in the nucleus, and by the telencephalic development factor FoxG1, which we show binds to FoxO-Smad complexes and blocks p21Cip1 expression. We suggest that the activity of this network confers resistance to TGF-β-mediated cytostasis during the development of the telencephalic neuroepithelium and in glioblastoma brain tumor cells.

Topography of acoustic response characteristics of the midbrain inferior colliculus (IC) of the Kunming mouse was studied by using extracellular recording techniques. The characteristic frequency (CF) range represented in the different divisions of the IC differed markedly: 4–15 kHz in the dorsal cortex (DC), 10–70 kHz in the central nucleus (CN), and 4–35 kHz in the external cortex (EC). The CF in the CN increased from dorsal and lateral to ventral and medial, higher CFs represented at its ventromedial part and lower CFs at its dorsal part. The isofrequency contours of CFs were incurvate. Minimum thresholds (MT) of the auditory neurons in DC and the central part of CN were lower (about 10 dB SPL), but considerably higher in the dorsal and ventral region of EC. Results suggest that each of the divisions in the mouse IC may have different auditory functions.