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Neuron number

Minimum number of hidden neurons [number of patterns]... [Pg.9]

ACh is released from the large non-spiny striatal interneurons (Fig. 15.10) which only represent some 5% of total striatal neuron number. Since ACh is excitatory and DA inhibitory on striatal neurons, various schemes have been proposed to balance their antagonistic action but the role of ACh in striatal function (and PD) appears to be relatively minor. [Pg.316]

Another level of cellular adaptation to psychotropic drug exposure involves the change in neuronal number through neurogenesis. Recent research has demonstrated that in the adult hippocampus, new cells constantly arise from immature neural precursor cells in the subgranular zone of the dendate gyrus, migrate into... [Pg.41]

Other areas of the human brain have not been studied in detail. In Alzheimer s disease, neurofibrillary tangles are found to colocalize with histamine in the tuberomammillary areas in the posterior hypothalamus1, and significantly reduced neuron numbers of the tuberomammillary nucleus in Alzheimer s brains33 have been reported. [Pg.246]

Gohlke JM, Griffith WC, Bartell SM, Lewandowski TA, Faustman EM (2002) A computational model for neocortical neuronogenesis predicts ethanol-induced neocortical neuron number deficits. Dev Neurosci, 24(6) 467-477. [Pg.264]

Pakkenberg B. 1990. Pronounced reduction of total neuron number in mediodorsal thalamic nucleus and nucleus accumbens in schizophrenics. Arch Gen Psychiatry 47 1023-1028. [Pg.309]

Heckers S, Heinsen H, Geiger B, Beckmann H. 1991. Hippocampal neuron number in schizophrenia. A stereological study. Arch Gen Psychiatry 48 1002-1008. [Pg.327]

Dorph-Petersen KA, Pierri JN, Wu Q, Sampson AR, Lewis DA. 2007. Primary visual cortex volume and total neuron number are reduced in schizophrenia. J Comp Neurol 501 290-301. [Pg.348]

Currently, there is a commonly expressed view that decreased cortical volume in schizophrenia is the result of a reduction of cortical neuropil, presumably due to an atrophy of neural dendrites and axons (e.g., (Selemon and Goldman-Rakic, 1999)). A direct prediction of this model is that neuron density should be increased in proportion to the decrease in cortical volume. While there is some evidence for increased density in the prefrontal cortex (Selemon et al., 1995, 2003), there are also a number of negative findings (Akbarian et al., 1995 Cotter et al., 2002 Cullen et al., 2006 Thune et al., 2001). In auditory areas, the available studies have not shown an altered neuron density, even with hemispheric comparisons (Beasley et al., 2005 Cotter et al., 2004 Smiley et al., 2002). An alternative hypothesis is that reduced cortical volume is accompanied by a loss of neuron number, but this issue remains to be addressed in the auditory cortex. In other brain areas, there is some evidence for decreased neuron number, although the differences are often subtle and statistically nonsignificant (Benes et al., 1986 Dorph-Petersen et al., 2007 Stark et al., 2004 Thune et al., 2001). Changes in total cell number in the cerebral cortex have been difficult to determine, because these measurements require a clearly identified reference volume. [Pg.372]

Zaborszky L, Vadasz C (2001) The midbrain dopaminergic system anatomy and genetic variation in dopamine neuron number of inbred mouse strains. Behav Genetics 37 47-59. [Pg.107]

Coleman PD, Flood DG (1987) Neuron numbers and dendritic extent in normal aging and Alzheimer s disease. Neurobiol Aging 8 521-545 Curtain CC, Ali F, Volitakis I, Cherny RA, Norton RS, Beyreuther K, Barrow CJ, Masters CL, Bush AI, Barnham KJ (2001) Alzheimer s disease amyloid-beta binds copper tmd zinc to generate an allosterically ordered membrane-penetrating structure conteiining superoxide dismutase-Uke subunits. J Biol Chem 276 20466-20473... [Pg.600]

Rapp, P.R., and Gallagher, M. 1996. Preserved neuron number in the hippocampus of aged rats with spatial learning deficits. PNAS 93, 9926-9930. [Pg.248]

Eisch, Ncstler, Duman, 2000 Santarclli et al., 2003) has demonstrated that antidepressant treatment increases neurogenesis, or new cell growth, in the hippocampus. This neurogenesis may block or reverse the effects of depression on hippocampal neurons. Further, the new cell growth appears to take several weeks to occur, and this may account for the fact that antidepressant medications typically take several weeks to exert their action. The findings suggest that increased cell proliferation and increased neuronal number may be a mechanism by which antidepressant treatment overcomes the atrophy and loss of hippocampal neurons associated with depression. [Pg.330]

FIG. 5. The number of errors on an inclined plane response flexibility problem (Thompson et al 1990) is shown for the same groups of animals as seen in Fig. 4. Saline-treated controls made the fewest errors. Animals exposed to the neurotoxin MAM were slower to abandon a previously learned solution to try new routes to food. However, animals treated postnatally with naltrexone, an opiate receptor antagonist reported to induce dendritic arborization and spine formation, showed performance similar to controls. Decreases in neuron number, such as seen with MAM exposure prenatally, have adverse effects on tests of rat intelligence. Treatments that induce dendritic arborization and synapse formation can ameliorate these deficits. The ability to modify brain structure permits direct testing of the causal role of variation in brain structure and behavioural performance. [Pg.88]

Pakkenberg B, Gundersen HJG 1997 Neocortical neuron number in humans effect of sex and age. J Comp Neurol 384 312-320... [Pg.90]

Figure 16 Considering a single neuron, number 5, in a non-input layer of the network, each of the four inputs, O,... Ot, is weighted by a coefficient, w,j... W4,. The neuron s output. Os, is the summed value. Is, of the inputs modified by the threshold function, f(I)... Figure 16 Considering a single neuron, number 5, in a non-input layer of the network, each of the four inputs, O,... Ot, is weighted by a coefficient, w,j... W4,. The neuron s output. Os, is the summed value. Is, of the inputs modified by the threshold function, f(I)...
Schumann CS, Amaral DG (2006) Stereological analysis of amygdala neuron number in autism. J. [Pg.28]

The possible model for brain growth for people with autism spectrum disorder consists of a period of overgrowth before the age of 5 years, in which several regions of the brain (and overall brain size) are enlarged. From 5 years onwards, this period of growth stops. In some autistic individuals this may be followed by a period of degeneration - a decrease in neuron numbers and volume reduction in some areas of the brain (Courchesne et al, 2007), as reported in various post-mortem studies. [Pg.130]

Kennedy DP, Semendeferi K, Courchesne E (2007) No reduction of spindle neuron number in frontoinsular cortex in autism. Brain Cogn 64 124-129. [Pg.157]


See other pages where Neuron number is mentioned: [Pg.826]    [Pg.352]    [Pg.750]    [Pg.10]    [Pg.267]    [Pg.10]    [Pg.41]    [Pg.42]    [Pg.366]    [Pg.366]    [Pg.659]    [Pg.276]    [Pg.288]    [Pg.344]    [Pg.826]    [Pg.71]    [Pg.286]    [Pg.622]    [Pg.98]    [Pg.233]    [Pg.344]    [Pg.233]    [Pg.344]    [Pg.86]    [Pg.89]    [Pg.604]   
See also in sourсe #XX -- [ Pg.3 ]

See also in sourсe #XX -- [ Pg.86 , Pg.88 ]




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