- Email: [email protected]
Correlation between the responses of lymphocytes and unpleasant emotional behaviour elicited by hypothalamic stimulation in cats
126
Abstracts 7th IOP Scientific Meeting /International
tween brain activity at birth and later language skills at 3 years of age. This study replicates and extends of one such study through 5 years of age by recording auditory-evoked responses (AERs) from the left and right hemisphere frontal, temporal, and parietal regions of 79 newborn infants to consonant-vowel syllables, Discriminant function analyses correctly classified over 80% of these infants at 5 years of age as belonging to either a low group with language performance measures one standard deviation below the group mean, a mean group, or a high group with language scores one standard deviation above the mean. This approach should greatly facilitate early assessment strategies designed to detect learning disabilities.
Application of chaos theory EEG in epileptic patients
to the analysis
of
M. Molnar a, J.E. Skinner ‘, G. Karmos a, aInstitute for Psychology, Hungarian Academy of Sciences, Budapest, b Totts Gap Medical Research L.&oratories, Hunpaq Bangor; MN, USA The objective of the present study was to calculate the correlation dimension (D2) of the EEG recorded before and during the occurrence of epileptic seizures. D2 is the quantitative measure of the number of independent variables responsible for the generation of the signal on the basis of which it becomes possible to draw inferences as to the complexity of the generator process itself. A new procedure, the point-correlation dimension (PD2i) was used to analyze data of the present experiments, yielding more accurate results than other previously used methods. The new method yields accurate values in relatively short epochs with non-stationary changes. Multichannel intraoperative EEG recordings were performed in patients with epileptic seizures resistant to conservative treatment. In patients with cortical foci the PD2i was shown to vary scatteredly in between low (around 2) and high (around 10) values only closest to the epileptic focus. This finding was typical prior to the development of generalized epileptic seizures. No such widely changing PD2i values were found in loci more distant to the epileptic focus which finding might give a clue to its localization.
Acknowledgements This publication is based on work sponsored by the Hungarian-US Science and Technology Joint Fund in cooperation with the Department of Health and Human Services and the Hungarian Academy of Sciences under project J.F. no. 129/91, and was also supported by OTKA grant T 4637.
Journal of Psychophysiology 18 (1994) 87-159
Dimensional analysis of the mismatch-negativity and the P3 event-related potential components M. Molnara,
J.E. Skinner b, V. CsCpC a, I. Winkler a, G.
Karmos ‘, a Institute for Psychology, Hungarian Acadetny of Sciences, Budapest, Hungary, b Tott’s Gap Medical Research Laboratories, Bangor, USA Although the experimental circumstances in which ERP components like the mismatch-negativity and the P3 wave appear are rather clear, less is known about the physiological processes they represent. The aim of this study was to apply recently developed mathematical tools of chaos theory for the analysis of event-related potentials (ERPs) recorded in paradigms in which the mismatch-negativity (MMN) and the P3 component appeared. A new method, the point-correlation dimension (PD2i) was used for data analysis which is more accurate than other algorithms for the calculation of the correlation dimension with nonstationarities in finite data epochs. ERPs were recorded from Fz, Cz and Pz in 6 subjects. With respect to baseline, the PD2i decreased significantly both during the ERPs in which the MMN and also in which the P3 was present, but the pattern and magnitude of this decrease were different in between these two situations. The pattern of PD2i changes during the occurrence of deviant stimuli eliciting the MMN suggest the presence of a frontal MMN generator. The conspicuous PD2i decrease during the occurrence of the P3 wave may support the “context closure” hypothesis concerning its generator mechanism.
Acknowledgements This work was sponsored by the Hungarian-US Science and Technology Joint Fund under project no. 129/91 and OTKA grant T 4637.
Correlation between the responses of lymphocytes and unpleasant emotional behaviour elicited by hypothalamic stimulation in cats Y. Mori a. J. Ma a, K. Kojima ‘. N. Tashiro a, K. Mizobe ‘, C. Kubo ‘. a Department of Neuropsychiatn; Kyushu University, Fukuoka, Japan, h Psychosonlatic Medicine, Kyushu University, Fukuoka, Japan To investigate the correlation between mental states and immune function, we examined the changes in the mitogen responses of lymphocytes that accompanied hypothalamitally elicited emotional behaviour in cats, Thirty-six cats were used, consisting of seven behavioural groups including a restlessness group (n=7), a defensive attack group (n=6), a defensive retreat group (n=4), a searching/sniffing group (n=4), a no-response group (n=5), a non-stimu-
Abstracts 7th IOP Scientific Meeting /International lated control group (n=5), and a home cage control group (n=5). The cats were stimulated with 60-Hz biphasic sine-wave pulses (129+X3 PA, 10 set on, 5 min off, 60 min/day) for 4 consecutive days. After stimulation, the responses of lymphocytes to phytohemagglutinin (PHA) in the peripheral blood were found to be significantly different between the above-mentioned groups of emotional behaviour (using one-way ANOVA, F6.29=3.37, p=O.O12). The responses indicated an increase in restlessness and attack, but remained unchanged regarding retreat or searching/sniffing, when compared with the no-response and the two control groups. That is, the responses of the lymphocytes change in different ways depending on the kinds of emotional behaviour. On the other hand, plasma cortisol significantly increased after stimulation in regard to behavioural restlessness, attack and also retreat, whereas no increase was observed for searching/sniffing. These results suggest that all unpleasant emotional behaviour (restlessness, attack, retreat) was accompanied by an increase in plasma cortisol, but the responses of the lymphocytes to PHA in the retreat group did not increase, whereas in the other unpleasant behaviour groups they increased. Thus the changes in the response may not be mediated by the hypothalamic-pituitary-adrenal axis alone. Local cortical blood flow, oxygen availability and impedance responses to sensory electrical stimulation Y. E. Moskalenko
a, C. Rovainen ‘. T. Woolsey h, B. Gaidar ‘, V. Semernia a, ’ Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia, b Washington University School of Medicine, St. Louis, MO, USA The objective was to observe changes in cortical neuronal activity by recording of local cerebral circulatory responses from the brain cortex blood vessels and to test the functional linkage of cerebrovascular responses to increased cortical neuronal activity. Dynamic on-line recordings of intensity of local blood flow (ICBF), changes in oxygen availability (PO,) and local electrical impedance were made with arrays of sharpened lOO+tm Pt electrodes in the somatosensory, visual and auditory cortex of rats and chinchillas anaesthetised with urethane (1 g/kg i.p.) and unanaesthetized chinchillas with chronically implanted electrodes. ICBF responses were recorded dynamically by PH, changes, with steady HZ electrochemical generation inside the brain tissue at a distance of 0.4-0.6 mm from the recording electrode. Dynamic PH, changes were calibrated by H, clearance with HZ inhalation at rest and during 60-90 set of 7.5% CO, inhalation. The PH, and PO, were record-
Journal of Psychophysiology 18 (1994) 87-159
127
ed by a polarographic method and pulsatile fluctuations of electrical impedance, using AC 30-50 kHz. Whisker mechanical stimulation (rats), and auditory and visual stimulation (chinchillas) has been used as a functional test for local changes in cortical neuronal activity. It was possible to obtain comparable data in animal experiments and in human subjects using neurosurgical patients with Pt electrodes, implanted into brain tissue by medical indications. It was shown that responses of the recorded parameters to 30-60 set global sensory stimulation of different modalities (all whiskers, flashes of light, clicks) had similar patterns in anaesthetised animals: during the first lo-20 set, ICBF, PO? and pulse fluctuations of electrical impedance were gradually increased with a latency of l-3 set and some stabilisation of ICBF was observed after this, but the POZ decreased at the same time. Values of ICBF increase were in the ranges lo-30% of the initial ICBF level. Maximal vascular responses were observed when some optimal parameters of stimulation were used (for all whiskers: duration of stimulation, 40-60 set; frequency of stimulation, 3 Hz; intervals between stimulation, 120 set). Patterns of response to selective sensory stimulation (single whiskers) was very changeable and depended on the position of the recording electrode to compare with the stimulated whisker. Changes in pattern of vascular responses during consecutive intervals of 80-120 set stimulation were also observed. Spatial resolution of ICBF responses to single-whisker stimulation was 0.2-0.4 mm. For unanaesthetized animals, an increase in ICBF to visual stimulation with a latency of 0.5-l set was more rapid and accompanied by a significant increase in PO,. Local responses to sensory stimulation in human subjects was similar to animals when visual or auditory stimulation was used. However, when the stimulus became significant, the ICBF responses increased sufficiently. The data obtained demonstrate that monitoring ICBF, PO, and pulse fluctuation of local electrical impedance may reflect dynamic changes of psychophysiological processes in the brain cortex during neuronal activation. The linkage between changes in neuronal activity and blood circulatory parameters may involve some rapid mechanism of a neurogenic nature. The royal tombs at Vergina: anatomical to an archaeological problem
solutions
of Bristol, J.H. Musgrave a, E.E. Rice h, a University Medical School, Bristol, UK, b University of Oxford, Oxford, UK In 1978-79 the late Prof. Manolis Andronicos excavated three royal tombs beneath the great tumulus at Vergina. The bones of the occupants have been studied independent-
Abstracts 7th IOP Scientific Meeting /International
tween brain activity at birth and later language skills at 3 years of age. This study replicates and extends of one such study through 5 years of age by recording auditory-evoked responses (AERs) from the left and right hemisphere frontal, temporal, and parietal regions of 79 newborn infants to consonant-vowel syllables, Discriminant function analyses correctly classified over 80% of these infants at 5 years of age as belonging to either a low group with language performance measures one standard deviation below the group mean, a mean group, or a high group with language scores one standard deviation above the mean. This approach should greatly facilitate early assessment strategies designed to detect learning disabilities.
Application of chaos theory EEG in epileptic patients
to the analysis
of
M. Molnar a, J.E. Skinner ‘, G. Karmos a, aInstitute for Psychology, Hungarian Academy of Sciences, Budapest, b Totts Gap Medical Research L.&oratories, Hunpaq Bangor; MN, USA The objective of the present study was to calculate the correlation dimension (D2) of the EEG recorded before and during the occurrence of epileptic seizures. D2 is the quantitative measure of the number of independent variables responsible for the generation of the signal on the basis of which it becomes possible to draw inferences as to the complexity of the generator process itself. A new procedure, the point-correlation dimension (PD2i) was used to analyze data of the present experiments, yielding more accurate results than other previously used methods. The new method yields accurate values in relatively short epochs with non-stationary changes. Multichannel intraoperative EEG recordings were performed in patients with epileptic seizures resistant to conservative treatment. In patients with cortical foci the PD2i was shown to vary scatteredly in between low (around 2) and high (around 10) values only closest to the epileptic focus. This finding was typical prior to the development of generalized epileptic seizures. No such widely changing PD2i values were found in loci more distant to the epileptic focus which finding might give a clue to its localization.
Acknowledgements This publication is based on work sponsored by the Hungarian-US Science and Technology Joint Fund in cooperation with the Department of Health and Human Services and the Hungarian Academy of Sciences under project J.F. no. 129/91, and was also supported by OTKA grant T 4637.
Journal of Psychophysiology 18 (1994) 87-159
Dimensional analysis of the mismatch-negativity and the P3 event-related potential components M. Molnara,
J.E. Skinner b, V. CsCpC a, I. Winkler a, G.
Karmos ‘, a Institute for Psychology, Hungarian Acadetny of Sciences, Budapest, Hungary, b Tott’s Gap Medical Research Laboratories, Bangor, USA Although the experimental circumstances in which ERP components like the mismatch-negativity and the P3 wave appear are rather clear, less is known about the physiological processes they represent. The aim of this study was to apply recently developed mathematical tools of chaos theory for the analysis of event-related potentials (ERPs) recorded in paradigms in which the mismatch-negativity (MMN) and the P3 component appeared. A new method, the point-correlation dimension (PD2i) was used for data analysis which is more accurate than other algorithms for the calculation of the correlation dimension with nonstationarities in finite data epochs. ERPs were recorded from Fz, Cz and Pz in 6 subjects. With respect to baseline, the PD2i decreased significantly both during the ERPs in which the MMN and also in which the P3 was present, but the pattern and magnitude of this decrease were different in between these two situations. The pattern of PD2i changes during the occurrence of deviant stimuli eliciting the MMN suggest the presence of a frontal MMN generator. The conspicuous PD2i decrease during the occurrence of the P3 wave may support the “context closure” hypothesis concerning its generator mechanism.
Acknowledgements This work was sponsored by the Hungarian-US Science and Technology Joint Fund under project no. 129/91 and OTKA grant T 4637.
Correlation between the responses of lymphocytes and unpleasant emotional behaviour elicited by hypothalamic stimulation in cats Y. Mori a. J. Ma a, K. Kojima ‘. N. Tashiro a, K. Mizobe ‘, C. Kubo ‘. a Department of Neuropsychiatn; Kyushu University, Fukuoka, Japan, h Psychosonlatic Medicine, Kyushu University, Fukuoka, Japan To investigate the correlation between mental states and immune function, we examined the changes in the mitogen responses of lymphocytes that accompanied hypothalamitally elicited emotional behaviour in cats, Thirty-six cats were used, consisting of seven behavioural groups including a restlessness group (n=7), a defensive attack group (n=6), a defensive retreat group (n=4), a searching/sniffing group (n=4), a no-response group (n=5), a non-stimu-
Abstracts 7th IOP Scientific Meeting /International lated control group (n=5), and a home cage control group (n=5). The cats were stimulated with 60-Hz biphasic sine-wave pulses (129+X3 PA, 10 set on, 5 min off, 60 min/day) for 4 consecutive days. After stimulation, the responses of lymphocytes to phytohemagglutinin (PHA) in the peripheral blood were found to be significantly different between the above-mentioned groups of emotional behaviour (using one-way ANOVA, F6.29=3.37, p=O.O12). The responses indicated an increase in restlessness and attack, but remained unchanged regarding retreat or searching/sniffing, when compared with the no-response and the two control groups. That is, the responses of the lymphocytes change in different ways depending on the kinds of emotional behaviour. On the other hand, plasma cortisol significantly increased after stimulation in regard to behavioural restlessness, attack and also retreat, whereas no increase was observed for searching/sniffing. These results suggest that all unpleasant emotional behaviour (restlessness, attack, retreat) was accompanied by an increase in plasma cortisol, but the responses of the lymphocytes to PHA in the retreat group did not increase, whereas in the other unpleasant behaviour groups they increased. Thus the changes in the response may not be mediated by the hypothalamic-pituitary-adrenal axis alone. Local cortical blood flow, oxygen availability and impedance responses to sensory electrical stimulation Y. E. Moskalenko
a, C. Rovainen ‘. T. Woolsey h, B. Gaidar ‘, V. Semernia a, ’ Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia, b Washington University School of Medicine, St. Louis, MO, USA The objective was to observe changes in cortical neuronal activity by recording of local cerebral circulatory responses from the brain cortex blood vessels and to test the functional linkage of cerebrovascular responses to increased cortical neuronal activity. Dynamic on-line recordings of intensity of local blood flow (ICBF), changes in oxygen availability (PO,) and local electrical impedance were made with arrays of sharpened lOO+tm Pt electrodes in the somatosensory, visual and auditory cortex of rats and chinchillas anaesthetised with urethane (1 g/kg i.p.) and unanaesthetized chinchillas with chronically implanted electrodes. ICBF responses were recorded dynamically by PH, changes, with steady HZ electrochemical generation inside the brain tissue at a distance of 0.4-0.6 mm from the recording electrode. Dynamic PH, changes were calibrated by H, clearance with HZ inhalation at rest and during 60-90 set of 7.5% CO, inhalation. The PH, and PO, were record-
Journal of Psychophysiology 18 (1994) 87-159
127
ed by a polarographic method and pulsatile fluctuations of electrical impedance, using AC 30-50 kHz. Whisker mechanical stimulation (rats), and auditory and visual stimulation (chinchillas) has been used as a functional test for local changes in cortical neuronal activity. It was possible to obtain comparable data in animal experiments and in human subjects using neurosurgical patients with Pt electrodes, implanted into brain tissue by medical indications. It was shown that responses of the recorded parameters to 30-60 set global sensory stimulation of different modalities (all whiskers, flashes of light, clicks) had similar patterns in anaesthetised animals: during the first lo-20 set, ICBF, PO? and pulse fluctuations of electrical impedance were gradually increased with a latency of l-3 set and some stabilisation of ICBF was observed after this, but the POZ decreased at the same time. Values of ICBF increase were in the ranges lo-30% of the initial ICBF level. Maximal vascular responses were observed when some optimal parameters of stimulation were used (for all whiskers: duration of stimulation, 40-60 set; frequency of stimulation, 3 Hz; intervals between stimulation, 120 set). Patterns of response to selective sensory stimulation (single whiskers) was very changeable and depended on the position of the recording electrode to compare with the stimulated whisker. Changes in pattern of vascular responses during consecutive intervals of 80-120 set stimulation were also observed. Spatial resolution of ICBF responses to single-whisker stimulation was 0.2-0.4 mm. For unanaesthetized animals, an increase in ICBF to visual stimulation with a latency of 0.5-l set was more rapid and accompanied by a significant increase in PO,. Local responses to sensory stimulation in human subjects was similar to animals when visual or auditory stimulation was used. However, when the stimulus became significant, the ICBF responses increased sufficiently. The data obtained demonstrate that monitoring ICBF, PO, and pulse fluctuation of local electrical impedance may reflect dynamic changes of psychophysiological processes in the brain cortex during neuronal activation. The linkage between changes in neuronal activity and blood circulatory parameters may involve some rapid mechanism of a neurogenic nature. The royal tombs at Vergina: anatomical to an archaeological problem
solutions
of Bristol, J.H. Musgrave a, E.E. Rice h, a University Medical School, Bristol, UK, b University of Oxford, Oxford, UK In 1978-79 the late Prof. Manolis Andronicos excavated three royal tombs beneath the great tumulus at Vergina. The bones of the occupants have been studied independent-