SK4/IK1-like channels mediate TEA-insensitive, Ca2+-activated K+ currents in bovine parotid acinar c

Difference in sensory dependence of occ1/Follistatin-related protein expression between macaques and

occ1/Follistatin-related protein (Frp) is strongly expressed in the primary visual cortex (V1) of macaque monkeys, and its expression is strongly down-regulated by intraoculartetrodotoxin (TTX) injection. The pronounced area selectivity of occ1/Frp mRNA expression occurs in macaques and marmosets, but not in mice, rabbits and ferrets, suggesting thatocc1/Frp is an important clue to the evolution of the primate cerebral cortex. To further determine species differences, we examined the sensory-input dependency of occ1/FrpmRNA expression in mice in comparison with macaque V1. In macaque V1, occ1/FrpmRNA expression level significantly decreased with even 1-day monocular deprivation (MD) by TTX injection. In contrast to that in macaques, however, the occ1/Frp mRNA expression in the visual cortex in mice was not down-regulated by 1- to 7-day MD by TTX injection. Similarly, MD had no effect on occ1/Frp mRNA expression level in the dorsal lateral geniculate nucleus of mice. In addition, the extirpation of the cochlear or olfactory epitheliumhad no effect on occ1/Frp mRNA expression in either the cochlear nucleus or the olfactory bulb in mice. Thus, occ1/Frp mRNA expression is independent of sensory-input in mice. The results suggest that activity-dependent occ1/Frp mRNA expression is not common between mice and monkeys, and that primate V1 has acquired a unique gene regulatory mechanism that enables a rapid response to environmental changes. The characteristic feature of the activity dependency of occ1/Frp mRNA expression is discussed, in comparison with that of the expression of the immediate-early genes, c-fos and zif268.

Differential expression pattern of OCC1-related, extracellular matrix proteins in the lateral genic

The extracellular matrix (ECM) plays important roles in the development and plasticity of the central nervous system, and it has been shown that it regulates reorganization of the neuronal network. We have found that expression of OCC1testican-1testican-2testican-3SPARC and SC1 mRNAs, which encode members of the OCC1-related family of ECM proteins, exhibits distinct activity-dependent expression patterns in the adult macaque visual cortex. This finding suggests that OCC1-related proteins play crucial roles in the visual processing pathway. In the present study, we examined mRNA expression patterns ofOCC1-related genes in the dorsal lateral geniculate nucleus (dLGN) of macaques. The mRNAs of testican-1 and testican-2 were strongly expressed in both excitatory projection neurons and GABAergic interneurons in the dLGN. Expression of testican-3 mRNA, which is predominantly observed in GABAergic interneurons in the cortex, was restricted to excitatory projection neurons in the dLGN. SPARC mRNA was strongly, and exclusively, expressed in glial cells in the dLGN. Interestingly, neuronal SC1 mRNA expression was abundantly observed in intercalated, koniocellular layers of the dLGN, while it was preferentially observed in blob regions of the primary visual area that receives color coding K-pathway projection from dLGN koniocellular layers, suggesting a pathway preference of expression. Finally, monocular inactivation experiments demonstrated that expression oftestican-1testican-2 and testican-3 mRNAs in the dLGN is dependent on sensory activity. Given their differential expression patterns and activity dependence, products of OCC1-related genes may modulate visual processing and plasticity at the level of the dLGN and the visual cortex.

VGLUT2 mRNA and protein expression in the visual thalamus and midbrain of prosimian galagos (Otolem

 Vesicular glutamate transporters (VGLUTs) control the storage and presynaptic release of glutamate in the central nervous system, and are involved in the majority of glutamatergic transmission in the brain. Two VGLUT isoforms, VGLUT1 and VGLUT2, are known to characterize complementary distributions of glutamatergic neurons in the rodent brain, which suggests that they are each responsible for unique circuits of excitatory transmission. In rodents, VGLUT2 is primarily utilized in thalamocortical circuits, and is strongly expressed in the primary sensory nuclei, including all areas of the visual thalamus. The distribution of VGLUT2 in the visual thalamus and midbrain has yet to be characterized in primate species. Thus, the present study describes the expression ofVGLUT2 mRNA and protein across the visual thalamus and superior colliculus of prosimian galagos to provide a better understanding of glutamatergic transmission in the primate brain. VGLUT2 is strongly expressed in all six layers of the dorsal lateral geniculate nucleus, and much less so in the intralaminar zones, which correspond to retinal and superior collicular inputs, respectively. The parvocellular and magnocellular layers expressed VGLUT2 mRNA more densely than the koniocellular layers. A patchy distribution of VGLUT2 positive terminals in the pulvinar complex possibly reflects inputs from the superior colliculus. The upper superficial granular layers of the superior colliculus, with inputs from the retina, most densely expressed VGLUT2 protein, while the lower superficial granular layers, with projections to the pulvinar, most densely expressed VGLUT2 mRNA. The results are consistent with the conclusion that retinal and superior colliculus projections to the thalamus depend highly on the VGLUT2 transporter, as do cortical projections from the magnocellular and parvocellular layers of the lateral geniculate nucleus and neurons of the pulvinar complex.

Identification of ocular dominance domains in New World owl monkeys by immediate-early gene expressi

 Ocular dominance columns (ODCs) have been well studied in the striate cortex (V1) of macaques, as well defined arrays of columnar structure that receive inputs from one eye or the other, whereas ODC expression seems more obscure in some New World primate species. ODCs have been identified by means of eye injections of transneuronal transporters and examination of cytochrome oxidase (CO) activity patterns after monocular enucleation. More recently, live-imaging techniques have been used to reveal ODCs. Here, we used the expression of immediate-early genes (IEGs), protooncogene, c-Fos, and zinc finger protein, Zif268, after monocular inactivation (MI) to identify ODCs in V1 of New World owl monkeys. Because IEG expression is more sensitive to activity changes than CO expression, it is capable of revealing activity maps in all layers throughout V1 and demonstrating brief activity changes within a couple of hours. Using IEGs, we not only revealed apparent ODCs in owl monkeys but also discovered a number of unique features of their ODCs. Distinct from those in macaques, these ODCs sometimes bridged to other columns in layer 4 (Brodmann layer 4C ). CO blobs straddled ODC borders in the central visual field, whereas they centered ODC patches in the peripheral visual field. In one case, the ODC pattern continued into V2. Finally, an elevation of IEG expression in layer 4 (4C) was observed along ODC borders after only brief MI. Our data provide insights into the structure and variability of ODCs in primates and revive debate over the functions and development of ODCs.

Expression of immediate-early genes reveals functional compartments within ocular dominance columns

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2706271/

What Does Cytochrome Oxidase Histochemistry Represent in the Visual Cortex?(Takahata T. 2016)

Ever since Wong–Riley first reported in the late 1970s that histological staining using the chemical reactions of cytochrome oxidase (CO), a metabolic enzyme in the mitochondria, is useful to reveal the cytoarchitecture of the brain (Wong-Riley, 1979), the CO histochemistry method has been widely used in the field of neuroanatomy, especially in carnivores and primates. It has been suggested that CO activity is coupled with the spike activity of neurons (Wong-Riley, 1979). Most strikingly, the use of CO histochemistry was critical to the discovery of patchy functional sub-compartments in the supragranular layers of primate V1, which are referred to as “CO blobs/puffs/patches” (Horton, 1984). Additionally, CO histochemistry revealed sub-compartments of “thick stripes,” “thin stripes,” and “pale stripes” in the middle layer of the secondary visual cortex (V2), which have been shown to possess distinct connections with V1 and other cortical areas (Sincich and Horton, 2002). These three stripes are also functionally distinct, as binocular disparity coding neurons are clustered into thick stripes (Chen et al., 2008). As such, CO histochemistry has revealed many normally cryptic functional compartments of the mammalian brain. Nonetheless, in this article, we aim to question the interpretation of results from CO histochemistry as “activity maps” of the brain.

http://zju.summon.serialssolutions.com/#!/search?bookMark=ePnHCXMwjV1NS8QwEA0iuFr8C5qLJ1lsm49tTiLVRfEgiHoNaT7WBWnFtrD-e2eSbtmjt7a8pGEa8jLNzJszcm4wNrsdYg6XI_FoEBwhdRNa06LUT4H___OVOgJfSErwhYBzjg-uF9NKCnttIU7IokSFFMFWp-QZ9azpfed7Wv8Onf3ElH76sts6WPJpFNaw-zpp9DWGksJA6LalMCL6se1H80VrjGLd3Wbkff3wVj8up6IDS1vC0JbC5RZY3uN5Ye6VUTDlLfc8d76oJDc8cOUKK7lsVAjWM2bhjolGWg6uT2AZeUr9Ynib_k6aERpVnOOD7mejp0mhhVK8bEoZYBMCbllTmYLBi1wRVkIYZ6Cvq9QXsoVGuYYW40E2Zux7fcdFhTXDSiz4lSfcnlrn98IeH22vo-012l5H20OTy9QEs1_Gfm4gkfAlysZl5CIhEjPPiP3nAMB1Ahwy9gyL0jbAdUok9dKMVP9H15NAOSbmD-wPn62wCQ

c-FOS Expression in the Visual System of TreeShrews After Monocular Inactivation.

Tree shrews possess an unusual segregation of ocular inputs to sublayers rather than columns in the primary visual cortex (V1). In this study, the lateral geniculate nucleus (LGN), superior colliculus (SC), pulvinar, and V1 were examined for changes in c-FOS, an immediate-early gene, expression after 1 or 24 hours of monocular inactivation with tetrodotoxin (TTX) in tree shrews. Monocular inactivation greatly reduced gene expression in LGN layers related to the blocked eye, whereas normally high to moderate levels were maintained in the layers that receive inputs from the intact eye. The SC and caudal pulvinar contralateral to the blocked eye had greatly (SC) or moderately (pulvinar) reduced gene expressions reflective of dependence on the contralateral eye. c-FOS expression in V1 was greatly reduced contralateral to the blocked eye, with most of the expression that remained in upper layer 4a and lower 4b and lower layer 6 regions. In contrast, much of V1 contralateral to the active eye showed normal levels of c-FOS expression, including the inner parts of sublayers 4a and 4b and layers 2, 3, and 6. In some cases, upper layer 4a and lower 4b showed a reduction of gene expression. Layers 5 and sublayer 3c had normally low levels of gene expression. The results reveal the functional dominance of the contralateral eye in activating the SC, pulvinar, and V1, and the results from V1 suggest that the sublaminar organization of layer 4 is more complex than previously realized.

http://zju.summon.serialssolutions.com/#!/search?bookMark=ePnHCXMw42LgTQStzc4rAe_hSmGAnuZjYKSfnJeqB6xATI2ZQDOQlma6lhZmwLzECVkmYGlmzgE_LdfS2IKTITBZ180_WCG1ArokNE8hM08BaLRCWWZxaWKOAuSsY4X8NAXQBK5CMdDz5cUK4Lu1FYBxmA9eyAnUA9ohABnf5GbQdHMNcfbQhVVB8QWQMx3iIaf3GsUD3RgPdqMxKWoBeaBKEQ