Pyramidal layer

Each of the three phases contains several major tasks that are conducted consecutively. The data collection pyramid is built from the bottom up through carrying out these seven tasks. Take one pyramid layer or one task out, and the whole structure becomes incomplete. 

The mRNA coding for 5-HT6 receptor has been localized in the rat brain by Northern blot, PCR, and in situ hybridization (206,207,213,214) (see also Fig. 10) and the protein by immunohistochemistry (213). The first and more detailed description on the localization of mRNA coding for 5-HT6 receptor was published by Ward and co-workers (215), reporting that the main rat brain regions where this receptor is expressed is the pyramidal layer of the olfactory tubercle, islands of Calleja, nucleus accumbens, striatum, hippocampus, and piriform cortex. At moderate levels, it is expressed in other cortical areas, the olfactory bulb, some nuclei of the hypothalamus and amygdale, the habenula, and the cerebellum. No mRNA expression is found in the raphe nucleus. These results were confirmed later (204). 

Dysbindin-1 gene expression in the human hippocampal formation shown seen with in situ hybridization. As seen at low magnification in (a), all major cell layers express the gene, but the level of expression is highest in the pyramidal layer of CA3 (c) and the polymorph layer of the DGh (d). Labeling with the antisense probe versus the sense probe is shown in (e) and (f), respectively. The scale bar in (a) is 1 mm, while those in (b-f) are 20 p.m. Reprinted with permission from Talbot et al. (2004)... 

Fig. 7a-d. Idealised lepresentations of various layer types observed in non-commensurate layer structures (a) octahedral layer, MX2, (111) B1 type (b) galena-like half octahedral (square pyramidal) layer, MX, (100) B1 type (c) the valleriite-like tetrahedral layer, MX, (111) anti-C 1 type (d) the mackinawite-like tetrahedral layer, MX, (100) anti-Cl type... 

L. Barbey, N. Nguyen, V. Caignart, M. Hervieu and B. Ravenau, Mixed oxides of cobalt and copper with a double pyramidal layer structure. Mat. Res. Bull, 27 (1992) 295-301. 

Sheldon PW, Aghajanian GK. 1990. Serotonin (5-HT) induces IPSPs in pyramidal layer cells of rat piriform cortex Evidence for the involvement of a 5-HT2-activated interneuron. Brain Res 506 62-69. 

The zones dissected were the approximately 60 ftm wide mossy fibre layer, the subjacent 60 yum wide zone comprising the pyramidal layer, and an overlying 80 /im strip of stratum radiatum. Enzyme activities are expressed relative to those of strips cut at right angles through all layers of hippocampus regio superior. These were 37.0 4- 1.5 /imoles/h/g dry wt. for GAD and 18.0 1.6 /unoles/h/g dry wt. for ChAc. Mean values S.E.M. (numbers of samples) are given. The data are from 3 rats. 

Storm-Mathisen No, they were not parallel except, it seems, in the region of the pyramidal cell layer of the hippocampus where they both had a peak of activity. For ChAc the maximum activity is in an infra-pyramidal zone, but for GAD we do not have a sensitive enough assay method to decide whether the peak is really in the pyramidal layer or in the infra- or supra-pyramidal zones. However the degeneration studies show that these two enzymes must be localized in different nerve structures. 

Recently, it has been reported that antitussives may act, at least in part, at the cortical level. Our microelectrophoretic study showed that all the antitussives studied inhibit spontaneous unit activities recorded from the pyramidal layer of the cerebral cortex of guinea pigs in vivo. To the best of our knowledge, the mechanism of inhibition of unit activities in the cerebral cortex has not yet been studied. However, one of its possible effects is the inhibition of GIRK channels, because GIRK channels are distributed in various regions of the brain, including the cerebral cortex (Ponce et al. 1996). 

Somatostatin applied to the cell bodies of neurones in the pyramidal layer of the CAl and CA2 regions of the rat hippocampus resulted in a strong excitation which was fast in onset and thus resembled that evoked by glutamate (Dodd and Kelly 1978). 

Pentylenetetrazol (45 mg/kg i.p. every 48 h) kindling-induced neuronal loss in the dentate area, in the hilus as well as in the pyramidal layer of CA3 could be prevented by pre-treatment of rats with piracetam (100 mg/kg i.p.) (Pohle et al. 1997). 

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