Palau is a small island nation in Micronesia in which many individuals with schizophrenia have been found in large, multiply affected families. Adolescents in these families have an elevated prevalence of especially diminished P50 inhibition. Adolescents identified by self-report and follow-up interview as displaying prodromal
symptoms also have an elevated prevalence of diminished P50 inhibition.11 Thus, diminished P50 inhibition is present in adolescents at risk for schizophrenia before the onset of psychotic symptoms (Figure 4). Figure 4. Inhibitors,research,lifescience,medical Percentages of P50 ratios in the abnormal range (amplitude of test wave/amplitude of conditioning wave>0.5) is elevated in adolescents with prodromal symptoms of schizophrenia or with first-degree Inhibitors,research,lifescience,medical relatives who have schizophrenia. Data are from … Attempts to measure P50 in selleck compound younger children have shown that normal adult levels of P50 inhibition are present in only about half of preadolescent children. In these younger children, diminished levels of inhibition do not correlate with any obvious psychopathology or familial risk. Rather, the children with diminished P50 inhibition tend to display increased levels of activity that are well within the
normal range for children of their age. P50 inhibition is not solely determined by linkage to CHRNA7. Inhibitors,research,lifescience,medical Adrenergic activity, for example, diminishes inhibitory interneuron response and is correlated with diminished P50 inhibition in normals. While it is not known whether normal children with diminished P50 inhibition have increased adrenergic activity it is known that Inhibitors,research,lifescience,medical children are much better able than adults to tolerate psychotomimetic drugs, such as amphetamine and ketamine, both of which increase catecholaminergic activity. Whether the apparent maturation of P50 inhibition at the end of adolescence and the loss of relative protection against Inhibitors,research,lifescience,medical psychotomimetic effects of drugs and the peak incidence of development of schizophrenia during this transition to adulthood
have a common neurobiological basis is a question that has yet to be addressed. Adrenergic activity itself varies considerably with the state of alertness and stress. Experimental elimination of adrenergic activity by pharmacological means in Drug_discovery animals results in the normalization of the inhibition of auditory responses to repeated stimuli. Similar experiments in normal children would be informative about the neurobiology of P50 inhibition, but exposure of these children to medication is problematic. However, loss of adrenergic activity is one of the physiological concomitants of rapid eye movement (REM) sleep. Therefore, a natural state exists in which P50 inhibition can be measured without the interference of adrenergic activity.