Biomedical subjects

Noriyuki Higo

Publications and source records attributed to Noriyuki Higo.

8 recordsLinked to original sources

PubMed2006

Expression of protein kinase C-substrate mRNAs in the basal ganglia of adult and infant macaque monkeys.

We performed in situ hybridization histochemistry on the monkey basal ganglia to investigate the mRNA localization of three protein kinase C substrates (GAP-43, MARCKS, and neurogranin), of which expression plays a role in structural changes in neurites and synapses. Weak hybridization signals for GAP-43 mRNA and intense signals for both MARCKS and neurogranin mRNAs were observed in the adult neostriatum. All three of the mRNAs were expressed in both substance P-positive direct pathway neurons and enkephalin-positive indirect pathway neurons. In the nucleus accumbens, the hybridization signals for the three mRNAs were weaker than those in the neostriatum. Double-label in situ hybridization histochemistry in the neostriatum revealed that GAP-43 and neurogranin mRNAs were expressed in a subset of MARCKS-positive neurons. While intense hybridization signals for MARCKS mRNA were observed in all of the other basal ganglia regions such as the globus pallidus, substantia innominata, subthalamic nucleus, and substantia nigra, intense signals for GAP-43 mRNA were restricted to the substantia innominata and substantia nigra pars compacta. No signal for neurogranin mRNA was observed in the basal ganglia regions outside the neostriatum and the nucleus accumbens. These results indicate that the protein kinase C substrates are abundant in some specific connections in cortico-basal ganglia circuits. Developmental analysis showed that the expression level in the putamen and nucleus accumbens, but not in the caudate nucleus, was higher in the infant than in the adult, suggesting that synaptic maturation in the caudate nucleus occurs earlier than that in the putamen and nucleus accumbens.

Age Factors↗

PubMed2006

Statistical parametric mapping of immunopositive cell density.

We developed a new method for comparing immunopositive cell densities across groups of animals and creating statistical parametric maps on standardized sections. As an example, we compared Iba-1 (microglial marker) positive cell densities in rats with (n=6) and without (n=6) unilateral injection of 1-methyl-4-phenylpyridinium salt (MPP+). Immunopositive cells were automatically counted in each animal over a coronal section in the midbrain (bregma -5.9 mm) and a positive cell density map was created for each animal. After the positive cell density map was normalized to a template section from an atlas, positive cell densities of the two groups were compared in each pixel over the section and a statistical parameter (p-value from t-test) was mapped on each pixel. We were able to detect significant increases of microglias in the side of MPP+ injection not only in the substantia nigra pars compacta but also in adjacent white matter. We also applied the same analysis to tyrosine hydroxylase stained sections and detected significant decreases of dopamine neurons in the side of MPP+ injection. The new method was proven to be useful for detecting significant changes of cell densities over the entire area of immunostained sections.

1-Methyl-4-phenylpyridinium↗

PubMed2006

Northern blot and in situ hybridization analyses for the neurogranin mRNA in the developing monkey cerebral cortex.

Neurogranin is a postsynaptic substrate for protein kinase C, and its expression is related to dendritic spine development and postsynaptic plasticity. Using both Northern blot analysis and in situ hybridization techniques, we investigated the developmental changes of neurogranin expression in the monkey cerebral cortex. In each of four neocortical areas examined, i.e., the prefrontal area (area FD of von Bonin and Bailey), the temporal association area (TE), the primary somatosensory area (PB), and the primary visual area (OC), the Northern blot analysis showed that the amount of neurogranin mRNA was low during the prenatal and perinatal periods until postnatal day 8. It increased during postnatal development and reached its peak value at postnatal day 70 (in area OC) or postnatal month 6 (in area FD, TE, and PB). After that, the amount of neurogranin mRNA in the cerebral neocortex decreased gradually until postnatal years 2-3. The in situ hybridization experiments also showed a transient increase of neurogranin mRNA in the neocortex during postnatal day 70 to postnatal month 6. The transient increase was prominent in layers II and III of areas FD and TE; deep in layer III of area PB; and in layers II, III, and IV of area OC. In the hippocampus, in contrast to the results in the neocortex, the expression of neurogranin mRNA was decreased almost continuously during the postnatal period. The transiently increased expression of neurogranin in the postnatal neocortex may be a molecular basis for the postsynaptic modification of afferent inputs possibly from subcortical structures.

Age Factors↗

PubMed2004

Cell type- and region-specific expression of neurogranin mRNA in the cerebral cortex of the macaque monkey.

Neurogranin is a postsynaptic substrate for protein kinase C (PKC). It has been identified in the central nervous system, and the expression has been related to postsynaptic plasticity. Using non-radioactive in situ hybridization histochemistry, we investigated whether mRNA expression of neurogranin varied among the cerebral region and cell types. In most areas of the neocortex excluding area OC (the primary visual area), intense signals were observed in the pyramidal cells in layers III, V and VI. In area OC, intense signals were observed in layers IV as well as layers III and VI. We previously showed that intense signals for GAP-43, a presynaptic PKC substrate, were observed in relay neurons of the lateral geniculate nucleus. From this result and the present result in area OC, we conclude that both pre- and postsynaptic PKC substrates (GAP-43 and neurogranin) are abundant in the geniculocortical synapses. In the hippocampus, intense signals were observed in the pyramidal cells in the subiculum. Taken together with our previous study showing intense signals for GAP-43 in Ammon's horn, the result indicates that both PKC substrates are abundant in the connections between neurons in Ammon's horn and in the subiculum.

Animals↗

PubMed2003

Cell type- and region-specific expression of protein kinase C-substrate mRNAs in the cerebellum of the macaque monkey.

We performed nonradioactive in situ hybridization histochemistry in the monkey cerebellum to investigate the localization of protein kinase C-substrate (growth-associated protein-43 [GAP-43], myristoylated alanine-rich C-kinase substrate [MARCKS], and neurogranin) mRNAs. Hybridization signals for GAP-43 mRNA were observed in the molecular and granule cell layers of both infant and adult cerebellar cortices. Signals for MARCKS mRNA were observed in the molecular, Purkinje cell, and granule cell layers of both infant and adult cortices. Moreover, both GAP-43 and MARCKS mRNAs were expressed in the external granule cell layer of the infant cortex. In the adult cerebellar vermis, signals for both GAP-43 and MARCKS mRNAs were more intense in lobules I, IX, and X than in the remaining lobules. In the adult hemisphere, both mRNAs were more intense in the flocculus and the dorsal paraflocculus than in other lobules. Such lobule-specific expressions were not prominent in the infant cerebellar cortex. Signals for neurogranin, a postsynaptic substrate for protein kinase C, were weak or not detectable in any regions of either the infant or adult cerebellar cortex. The prominent signals for MARCKS mRNA were observed in the deep cerebellar nuclei, but signals for both GAP-43 and neurogranin mRNAs were weak or not detectable. The prominent signals for both GAP-43 and MARCKS mRNAs were observed in the inferior olive, but signals for neurogranin were weak or not detectable. The cell type- and region-specific expression of GAP-43 and MARCKS mRNAs in the cerebellum may be related to functional specialization regarding plasticity in each type of cell and each region of the cerebellum.

Age Factors↗

PubMed2002

Expression of super cervical ganglion-10 (SCG-10) mRNA in the monkey cerebral cortex during postnatal development.

We used Northern blot analysis to measure SCG10 mRNA expression in various areas of the monkey cerebral cortex during postnatal development. In all areas, SCG10 mRNA expression was highest immediately after birth, decreased sharply until postnatal day 70 (P70) and then decreased slowly until the adult stage. Expression levels were similar in all areas at all time points during development, including the adult stage. These findings confirm that axonal growth in the monkey cerebral cortex is most vigorous before or during the perinatal period, progresses similarly in all areas until P70, and continues at lower levels during late development.

Aging↗

PubMed2002

Northern blot and in situ hybridization analyses of MARCKS mRNA expression in the cerebral cortex of the macaque monkey.

Myristoylated alanine-rich C-kinase substrate (MARCKS) is a major substrate for protein kinase C, and is involved in synaptic plasticity. Using both Northern blot and in situ hybridization techniques, we investigated whether MARCKS expression varied according to the cerebral region, including the hippocampal formation, or according to the type of neuron. Northern blot analysis showed that the MARCKS mRNA level was higher in the association areas than in the primary sensory and motor areas of the cerebral neocortex. MARCKS mRNA levels in the hippocampus and the amygdala were as high as those in the association areas. The in situ hybridization experiments confirmed the Northern blot results and showed the distribution and characteristics of MARCKS mRNA-positive neurons. In the association areas of the neocortex, prominent signals were observed in neurons in layers II-VI. In the primary areas, prominent signals were restricted to neurons in layers IV-VI. In the hippocampus, the most intense hybridization signals were observed in neurons in the granule cell layer of the dentate gyrus. The observed region-specific expression might reflect functional specialization for plasticity in individual regions of the monkey cerebral cortex.

Animals↗

PubMedDate not supplied

Expression of MARCKS mRNA in lateral geniculate nucleus and visual cortex of normal and monocularly deprived macaque monkeys.

We performed a nonradioactive in situ hybridization histochemistry (ISH) study of the lateral geniculate nucleus (LGN) and the primary visual area (area 17) of the macaque monkey to investigate mRNA expression of the myristoylated alanine-rich C-kinase substrate (MARCKS), a major protein kinase C (PKC) substrate. In the LGN, intense hybridization signals were observed in both magnocellular neurons (layers 1 and 2) and parvocellular neurons (layers 3 to 6). Double labeling using ISH and immunofluorescence revealed that MARCKS mRNA was coexpressed with the alpha-subunit of type II calcium/calmodulin-dependent protein kinase, indicating that MARCKS mRNA is also expressed in koniocellular neurons in the LGN. GABA-immunoreactive neurons in the LGN did not contain MARCKS mRNA, indicating that MARCKS mRNA is not expressed in inhibitory interneurons. The signals were generally weak in area 17, and intense signals were restricted to large neurons in layers IVB, V, and VI. GABA-immunoreactive neurons in layers II-VI of area 17 did not contain MARCKS mRNA. Double-label ISH revealed that MARCKS mRNA was coexpressed with mRNA of GAP-43, another PKC substrate, in neurons of both the LGN and area 17. To determine whether the expression of MARCKS mRNA is regulated by retinal activity, we performed ISH in the LGN and area 17 of monkeys deprived of monocular visual input by tetrodotoxin. After monocular deprivation for 5 to 30 days, MARCKS mRNA was down-regulated in the LGN, but not in area 17. These results suggest that MARCKS mediates the activity-dependent changes in the excitatory relay neurons in the LGN.

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