Granule cells, hippocampus

Isokawa, M (1996) Decrement of GABAa receptor mediated inhibitory postysynaptic currents in dentate granule cells in epileptic hippocampus. J. Neurophysiol. 75 1901-1908. 

Anandamide is found in human brain 100 pmol/g in the hippocampus, 75 pmol/g in the thalamus, 60 pmol/g in the cerebellum, and 55 pmol/g in the striatum (Martin, 1999). The concentration of AEA increases postmortem, especially when the brain is kept at ambient temperature. Furthermore, AEA surges are observed when cerebellar granule cells are treated in hypoxic conditions (Hillard, 1997). Although such concentration increases may be artifacts of postmortem brain damage, they may also occur in living tissue under certain conditions, such as hypoxia. 

Rat (Wistar) 3 wk 7 d/wk ad lib (W) 15 (increase in volume of mossy fiber zone, granule cell layer, and commissural association zone in hippocampus of offspring) Slomianka et al. 1989 PbAc... 

AC7 is found in several tissues, with highest levels in lung and spleen, moderate levels in heart, and low levels in brain, kidney and skeletal muscle [13, 14]. In brain, the highest levels are found in cerebellar granule cells, while lower levels are seen in hippocampus, neocortex and striatum. AC9 is expressed in brain and skeletal muscle but also displays widespread distribution in other tissues. The soluble isoform sAC is enriched in testes but is also found in other tissues. 

Normally the dentate granule cells of hippocampus limit excessive activation of their targets, the CA3 pyramidal cells 632... 

Ribak, C. E., Korn, M. J., Shan, Z. and Obenaus,A. Dendritic growth cones and recurrent basal dendrites are typical features of newly generated dentate granule cells in the adult hippocampus. Brain Res. 1000 195-199, 2004. 

Both anandamide and 2-AG are inactivated by enzymatic hydrolysis (Goparaju et al. 1998). Fatty acid amide hydrolase (FAAH) is an enzyme that catalyses their hydrolysis. High concentrations of FAAH were found in the cerebellum, hippocampus and neocortex of rat brain, which are also rich in cannabinoid receptors. Further, there is a complementary pattern of distribution of FAAH and the CBl receptor. For example, in the cerebellum, FAAH is found in the cell bodies of Purkinje cells and the CBl receptor is found in the axons of granule cells and basket cells, which are presynaptic to Purkinje cells. 2-AG may also be inactivated by direct esterification into membrane phospholipids. Cannabinoid Receptors... 

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). 

A typical neuron consists of a cell body and an axonal projection through which information in the form of an action potential passes from the cell body to the axonal terminal. Information is received by the cell body via a complex array of dendrites which make contact with adjacent neurons. The structural complexity and the number of dendritic processes vary according to the type of nerve cell and its physiological function. For example, the granule cells in the dentate gyrus of the hippocampus (a region of the brain which plays a role in short-term memory) receives and integrates information from up to 10 000 other cells in the vicinity. 

Cerebral cortex (layer I-VI, selected interneurons and principal cells) hippocampus (selected interneurons and principal cells) pallidum striatum (interneurons) thalamic relay nuclei olfactory bulb (mitral cells and interneurons) cerebellum (Purkinje cells and granule cells) deep cerebellar nuclei amygdala basal forebrain substantia nigra pars reticulata inferior colliculus brainstem... 

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

The adult hippocampus also contains progenitors/ stem cells that are capable of differentiating into new hippocampal granule neurons. Hippocampal progenitor cells will give rise to new neurons in adult rodent, primate, and human brains (Eriksson et ah, 1998). The new hippocampal granule cells extend axons that are appropriately connected to the pyramidal cells in the CAS region. 

Yoneda Y., Ogita K., Azuma Y., Kuramoto N., Manabe T., and Kitayama T. (1999). Predominant expression of nuclear activator protein-1 complex with DNA binding activity following systemic administration ofN-methyl-D-aspartate in dentate granule cells of murine hippocampus. Neuroscience 93 19-31. 

Camkk2 Brain (parietal cortex, cerebellum (granule cells), caudate-putamen, hippocampus, olfactory bulb, brainstem, mesencephalon and thalamus) Thymus, testis, spleen, lungs, many other tissues (Kitani et al., 1997 Anderson et al., 1998 Sakagami et al., 2000 Hsu et al., 2001 Vinet et al., 2003)... 

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