Neurophysiological Measures Related to Levels of 5-Hydroxyindoleacetic Acid, Homovanillic Acid and Tryptophan in Cerebrospinal Fluid of Psychiatric Patients

Abstract

In 26 patients with psychiatric disorders, EEG, and visual averaged evoked responses (VAER) were recorded. In the analysis of the EEG, the mean integrated amplitude (MIA), its within patient variance (WPV), and the coefficient of variation CV = √WPV/MIA) × 100 were calculated. Patients were grouped as augmenters or reducers according to their tendency in the VAER recording to augment or to reduce the intensity of incoming signals with increasing stimulus intensity. The content of monoamine metabolites, 5-hydroxyindoleacetic acid, 5-HIAA, and homovanillic acid (HVA), and – for 17 patients -tryptophan, in the cerebrospinal fluid was determined. In the analysis of the results, WPV in the α-band was found to be significantly correlated to HVA (r = 0.45, p < 0.02) and to 5-HIAA (r = 0.34, p < 0.05). In a multiple regression analysis, the correlation between WPV and HVA was found to be the most important. CV was found to be significantly correlated to tryptophan (r = 0.68, p < 0.01). In the analysis of the results of the VAER, reducers were found to have higher levels of 5-HIAA and tryptophan and significantly higher values of HVA. The results are discussed in relation to earlier neurophysiological and biochemical theories about psychiatric patients.

Augmenting/Reducing: an Adaptive Switch Mechanism to Cope with Incoming Signals in Healthy Subjects and Psychiatric Patients

“…Thus, the turnover of serotonin, reflected by the level of its metabolite 5-H1AA in CSF, might indicate levels of activity in the inhibitory processes. Our findings concerning 5-H1AA in CSF and Aug/Red are not so clear-cut as the results concerning HVA, but they point in the same direction (table VI) (20,37).…”

“…As can be seen in figure 11, there is a significant correlation between the different Aug/Red responses and HVA level in CSF. Moreover, table VII shows that the highest amount of HVA is found in the Red groups C and D. This finding would thus suggest a high activity of inhibitory processes in Red (20,37).…”

“…However, differences in the measuring technique make comparison with studies in humans difficult. Gottfries et al (20) reported high levels of homovanillic acid (HVA) and of 5-hydroxyindole acetic acid (5-H1AA) in the cerebrospinal fluid (CSF) in Red (V.AER measures). Buchsbaum et al (10) reported a low monoamine oxidase (MAO) activity (tryptamine substratum) in platelets in V.AER Aug.…”

Effects of the 5-HT2A Agonist Psilocybin on Mismatch Negativity Generation and AX-Continuous Performance Task: Implications for the Neuropharmacology of Cognitive Deficits in Schizophrenia

“…N1 intensity dependence refers to the increase of N1 amplitude with increasing stimulus intensity (Hegerl and Juckel, 1994b). There is considerable Effects of psilocybin on MMN generation and AX-CPT D Umbricht et al evidence that a low serotonergic tone is associated with an increased N1 intensity dependence (Gottfries et al, 1976;Hegerl et al, 1995;Juckel et al, 1999;Perris et al, 1979;Tuchtenhagen et al, 2000;von Knorring and Perris, 1981;Wang et al, 1996), an effect mediated in particular through the 5-HT 1A and 5-HT 2A receptor (Juckel et al, 1997). One would therefore expect a 5-HT 2A agonist to reduce N1 intensity dependence or, with intensity kept constant, to reduce N1 amplitude.…”

Biochemistry of the Augmenting-Reducing Response in Visual Evoked Potentials

“…The series included patients with manic-depressive disorders, reactive-depressive disorders, dementia in old age, other psychotic disorders and neuroses. The series is presented in detail elsewhere (8).…”