Pyramidal neurones cerebral cortex

Pyramidal neurons are the principal long-projecting cells of the cerebral cortex and hippocampus. They are so named because of the characteristic large apical dendrite, giving them a pyramidal shape. 

The corticospinal tracts originate in the cerebral cortex. Neurons of the primary motor cortex are referred to as pyramidal cells. Most of these neurons axons descend directly to the alpha motor neurons in the spinal cord. In... 

CYP2D6 mRNA and protein in human brain regions by RT-PCR, Northern blot, and Immunobiot, in situ hybridization and IHC shows constitutive CYP2D6 mRNA expression in neurons of cerebral cortex, Purkinje and granule cell layers of cerebellum, reticular neurons of midbrain and pyramidal neurons of C47, CA2, and CAS subfields of hippocampus. Protein found in cortex, cerebellum, midbrain, striatum, and thalamus of human brain. IHC shows CYP2D6 in dendrites of Purkinje and cortical neurons and neuronal soma (Chinta et al., 2002). 

CYP2E1 mRNA seen in neurons of the cerebral cortex, Purkinje and granule cells of cerebellum, granule cells of dentate gyrus, and pyramidal neurons of CA1, CA2, and CA3 subfields of hippocampus in rat and human brain by in situ hybridization ethanol-induced brain expression in rat (Upadhya et al., 2000). 

Goldman-Rakic PS, Leranth C, Williams SM, Mons N, Geffard M (1989) Dopamine synaptic complex with pyramidal neurons in primate cerebral cortex, Proc Natl Acad Sci USA 86 9015-9019... 

Hippocampus (pyramidal cells) olfactory bulb (granule cells, periglomerular cells) cerebral cortex amygdala hypothalamus superior colliculus superior olivary neurons spinal trigeminal neurons spinal cord... 

Glutamatergic neurons are widely distributed throughout the entire brain. Most glutamatergic neurons are so-called projection neurons their axon projects into distant brain regions. Prominent glutamatergic pathways are the connections between different regions of the cerebral cortex (cortico-cortical projections), the connections between thalamus and cortex, and the projections from cortex to striatum (extrapyramidal pathway) and from cortex to brain stem/spinal chord (pyramidal pathway). 

Tire neuronal events that occur within the cerebral cortex are extraordinarily complex and little understood 409 In what way the brain is able to initiate voluntary movement of muscles is obscure. However, it is established that the signals that travel out of the brain down the efferent fibers to the muscles arise from large motor neurons of the motor cortex,410 a region that extends in a band across the brain and adjacent to the sensory cortex (Fig. 30-14). The axons of these cells form the pyramidal tract that carries impulses downward to synapses in the spinal cord and from there to the neuromuscular junctions. These are specialized synapses at which acetycholine is released, carrying the signal to the muscle fibers themselves. Passing over the cell surface and into the... 

Conti F., DeBiasi S., Minelli A., Rothstein J. D., and Melone M. (1998). EAAC1, a high-affinity glutamate tranporter, is localized to astrocytes and gabaergic neurons besides pyramidal cells in the rat cerebral cortex. Cereb. Cortex 8 108-116. 

Acetylcholine is the neurotransmitter found in many areas of the brain as well as in the periphery (skeletal neuromuscular junction, some autonomic synapses). In the brain, acetylcholine is abundant in the cerebral cortex, and seems to play a critical role in cognition and memory.22 32 Neurons originating in the large pyramidal cells of the motor cortex and many neurons originating in the basal ganglia also secrete acetylcholine from their terminal axons. In general, acetylcholine synapses in the CNS are excitatory in nature. 

In the human brain, the knowledge of the distribution of the mRNAs coding for 5-HT3A and 5-HT3B receptor subunits is much more limited. By in situ RT-PCR, the co-localization of both subunit mRNAs in a population of neurons in monkey lateral amygdala, and entorhinal cortex and in pyramidal cells of the human cerebral cortex (163) has been described. 

Acute cerebral ischemia affects neurons first and the more resistant glia and blood vessels in later stages. Deep cortical layers such as layer III of the cerebral cortex are especially vulnerable, mainly in the parietal and occipital regions and less in the frontal and temporal areas. The more vulnerable neurons are those of the caudate and putamen, the pyramidal cells of Sommer s area and the Purkinje cells in the cerebellum. The thalamus and brainstem are more resistant to hypoxia and ischemia. White matter is generally considered to be more resistant than grey matter. 

Two main subdivisions have been recognized in the SN since the first detailed studies of this structure (Mingazzini, 1888 Sano, 1910 Cajal, 1911). In particular, Mingazzini (1888), who impregnated human midbrain tissue with the Golgi technique, was so impressed by the appearance of the different portions of the SN that he considered the organization of this structure similar to the layered organization of the cerebral cortex and described the SN neurons as pyramidal cells. 

Pyramidal cell— named on the basis of the cell body s shape. It is one of the two major neuronal types found in the cerebral cortex. It has a large apical dendrite, which extends vertically from the top of the pyramid, and basal dendrites, which come off horizontally at the base of the pyramid. The axon also typically extends from the base. 

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