The locations of current vectors, which explain more than 90% of the observed brain signals, have their origin in the hippocampal formation. Hence, limbic structures contribute to information processing during cognitive discrimination in the auditory paradigm. Figure 3. Limbic sources of P300m dipoles. Three-dimensional Inhibitors,research,lifescience,medical reconstruction of the major sources explaining the pattern presented in Figure 2. Note the location in the posterior part of the hippocampal formation. Functional aspects and neuropharmacology P300 characteristics such as amplitude and latency are altered during aging.14,15 The

pathophysiological state is reflected in the brain activity.16-18 Moreover, the deterioration effect has been shown to coincide with the clinical severity Inhibitors,research,lifescience,medical of mental illness in demented patients.19-21 The activation pattern has been shown to be under cholinergic control: scopolamine is able to attenuate or even abolish

the P300 response in young healthy volunteers.22-24 Figure 4 shows the postdosing evolution and statistical comparison of the effect, of the cholinergic antagonist scopolamine (0.5 mg, subcutaneous [SC], top). As can be seen, Inhibitors,research,lifescience,medical a significant frontocentral attenuation is present in healthy volunteers (upper right panel). Such effects parallel the deterioration in mnemonic capacities induced by the drug (see below). Veliparib Acetylcholinesterase (AchE) inhibitors, on the contrary, induce Inhibitors,research,lifescience,medical increases in these topographic regions after oral administration. Indeed, oral administration of donepezil, a representative of the class of nootropic compounds,

induces the opposite effects (Figure 4, bottom). This type Inhibitors,research,lifescience,medical of effect, is in full agreement with the existing literature.26,27 Figure 4. Cholinergic control of P300 in young healthy volunteers. Top: Mapping result show the dramatic deterioration under scopolamine (0.5 mg, subcutaneous). Pvalues are issued after multiple nonparametric comparisons (Wilcoxon) between two experimental conditions … The message so far is that the relationship between neuropharmacology of the cholinergic system, which is Amisulpride fairly straightforward, on the one hand, and evoked (cognitive) responses reflecting conscious attention, which fits with the functional brain anatomy of limbic circuitry, on the other, form an ideal basis to study drug interaction in research in the field of psychiatric disorders. Proof of concept The “pseudo-state/trait marker” concept As mentioned previously, the aging brain provides a natural decline in the properties of the cognitive response, such as the P300 waves (Figure 5, top). Comparison of healthy male subjects aged 55 years and older with young subjects aged between 18 and 35 years yields significant attenuation in large parietal and temporal scalp regions.