12 For schoolaged children, the REM state would also be achieved after sleep deprivation or by all-night recording, but for newborns, REM is
a frequently achieved state during the day. Therefore, we have recorded P50 inhibition during the first 3 months of life. In initial experiments, infants could indeed be recorded during REM sleep and P50 responses were elicited.13 The degree of inhibition was correlated with gestational age, calculated from conception. This method is used to avoid the confound of premature birth in the calculation of perinatal development. Inhibitors,research,lifescience,medical By the first 3 months of life, most infants have developed near-adult levels of P50 inhibition (Figure 5). Recording of infants at risk for schizophrenia is a logical next step in determining whether or not the neurobiological processes that result in abnormal P50 inhibition in schizophrenia are present as early as the neonatal period. Figure 5. Relationship between age and selected electrophysiological variables. A. P50 T/C ratio generally decreases (ie, sensory gating Inhibitors,research,lifescience,medical improves) with advancing age. B. Electroencephalogram (EEG) spectral power in the θ band (4-8 Hz), associated
with rapid-eye … Other inhibitory dysfunctions associated with schizophrenia are also present during childhood. Persons with schizophrenia have abnormal smooth pursuit eye Inhibitors,research,lifescience,medical movement tracking. The task consists of following a slowly moving target, which the subject must follow with his or her eyes, while eye movement is monitored using infrared reflectometry. Normal persons are able to move their eyes precisely, so that the image of the target always remains in the small foveal region of the retina. Persons with schizophrenia and some of their Inhibitors,research,lifescience,medical relatives have diminished performance of the task. One of the elements of this abnormality is the inability to inhibit saccadic eye movements, so that their eyes jump ahead of the target and then wait for the target to catch up (Figure 6). Functional magnetic resonance
imaging during the task this website reveals increased hemodynamic activity in the hippocampus (Figure 7). 14 This increased activity is consistent with the putative decreased Inhibitors,research,lifescience,medical hippocampal inhibition that has also been proposed as a mechanism for the diminished inhibitory gating of the P50 response.15 Terminal deoxynucleotidyl transferase Figure 6. In schizophrenia, there are several abnormalities in smooth pursuit eye movements. One of these is elevated frequency of anticipatory saccades, the failure to inhibit fast or saccadic eye movements that cause the eyes to jump ahead of the slowly moving … Figure 7. Functional magnetic resonance imaging of 14 schizophrenics and 14 normals performing smooth pursuit eye movements. The images are comparisons between the two groups. The schizophrenics have increased hemodynamic activity in the hippocampus, consistent … About half of children with a parent who has schizophrenia also have abnormal smooth pursuit eye movements with the intrusion of saccades, which can be detected as early as age 6.