The acute effects of diazepam and sodium valproate on the human SEP (Somatosensory Evoked Potential) and EEG

The acute effects of diazepam (DZP) and sodium valproate (VPA) on somatosensory evoked potential (SEP) were studied with 16 healthy male subjects (26~43 y. o.). In the two experimental sessions on different days, DZP (0.1 mg/kg) or VP A (5 mg/kg) was orally administered for each subjects. EEGs containing SEPs evoked by electric stimuli once every 5 sec were derived from the two derivations (monopolar : C3'→A1+2, bipolar : C3'→F3') and recorded into magnetic tape, before and 30, 60, and 90 min after the administration of these drugs. Reproducing the tape, SEPs with 1024 msec of analysis time were obtained by averaging 100 responses, and EEGs were subjected to the frequency analysis. Consecutive changes of group mean SEP were studied. Individual SEPs were subjected to the component analysis, and to the statistical assessment together with EEG. The following results were obtained. 1. After the administration of DZP, amplitudes of middle and long latency compenent significantly decreased and continued from early stage. The latencies were significantly increased and recovered for the middle latency component (P3~N4), while decreased for those of long latency component (N5~) later. After administration of DZP, in EEG, the power % were significantly increased for not only drug induced β but also δ and θ, and they had significant positive correlation with the latencies of middle latency component. These results suggest that DZP has the transient inhibitory effect to brainstem reticular formation, thalamus and hypothalamus, and continuous inhibitory effect to cerebral gray matter from early stage, and might facilitate transmission in cerebral white matter through GABA neuron system. 2. After the administration of VPA, the latencies did not significantly change for latencies of middle latency component, but increased for these of long latency component (P6~). Amplitudes of middle and long latency components decreased significantly. In EEG, the power % were significantly increased for α1 and decreased for β2. These results suggest that VPA has no or weak effect to brainstem reticular formation, thalamus and hypothalamus, while it has the inhibitory effect to cerebral gray matter through GABA neuron system

The acute effects of mianserin hydrochloride and sodium valproate on the human AEP (Auditory Evoked Potential) and EEG

The acute effects of mianserin hydrochloride (MSR) and sodium valproate (VPA) were studied by auditory evoked potential (AEP), with 16 healthy male subjects (26~43 y. o.). In the two experimental session on different days, MSR (0.3 mg/kg) or VPA (5 mg/ kg) were orally administered for each subjects. EEGs containing AEPs evoked by click stimuli once every 5 sec were derived from the two derivations (3 ch : Cz→A1+2, 6 ch : Cz →T 5 ) and recorded into magnetic tape. Reproducing the tape, AEPs with 1024 msec of analysis time were obtained by averaging 100 responses, and EEGs were subjected to the frequency analysis. In the experimental session, EEG containing AEPs were recorded befored and 60, 120, and 180 min after the administration of MSR, and before and 30, 60, and 90 min after VPA. Consecutive changes of group mean AEP were studied. Individual AEPs were subjected to the component analysis, and to the statistical assessment together with EEG. The followig results were obtained. 1. After the administration of MSR, P2 and P3 latenies of the middle latency components and those of long latency components (P6~) of AEP significantly increased. All of significant changes were decrease for the peak-to-peak amplitudes of the AEP components. These inhibitory effects of MSR on AEP were attributed to the antihistaminergic effect of MSR. Moreover, significant positive correlation was found between δ and θ power % of EEG and P2 and P3 latencies, significant negative correlation between α2 and β2 power % of EEG and P2 latency, and between α2 power % of EEG and P3 latency. These results indicate that not only P2 but also P3 reflect the activities of the reticular formation and thalamocortical systems. 2. After the administration of VPA, latencies of long latency components (P6~) significantly increased, but those of middle latency components (Pl~P3) did not significantly change. These results were attributed to the inhibitory effects of VPA on the cerebral cortex through GABA neuron system. 3. From these results, it was considered that MSR has more inhibitory effect on the reticular formation and thalamocortical systems, and VPA has main inhibitory effect on the cerebral cortex

The acute effects of mianserin hydrochloride and sodium valproate on the human VEP (Visual Evoked Potential) and EEG

The acute effects of mianserin hydrochloride (MSR) and sodium valproate (VPA) were studied by visual evoked potential (VEP), with 16 healthy male subjects (26~43 y. o.). In the two experimental session on different days, MSR (0.3 mg/kg) or VPA (5 mg/kg) were orally administered for each subjects. EEGs containing VEPs evoked by flash stimuli once every 5 sec were derived from the two derivations (2ch : 01→A1+2, 5ch : 01→Cz) and recorded into magnetic tape. Reproducing the tape, VEPs with 1024 msec of analysis time were obtained by averaging 100 responses, and EEGs were subjected to the frequency ayalysis. In the experimental session, EEG containing VEPs were recorded before and 60, 120, and 180 min after the administration of MSR, and before and 30, 60, and 90 min after VPA. Consecutive change of group mean VEP were studied. Individual VEPs were subjected to the component analysis, and to the statistical assessment together with EEG. The following results were obtained. 1. After the administration of MSR, P3 and N3 latencies of the short latency components of VEP significantly increased. And most of those of long latency components (N6~) significantly increased. The peak-to-peak amplitude P3-N3 and N3-P4 significantly decreased. In EEG, the power % of δ, θ and β2 frequency band increased, and that of α2 decreased. Significant positive correlation was found between δ and θ power % of EEG and latencies and amplitudes of VEP, and significant negative correlation was found between α2 and β2 power % and latencies and amplitudes. These findings indicate the inhibitory effect of MSR mainly on the lateral geniculate body and the optic radiation in the visual system. 2. After the administration of VPA, latencies of the long latency components (P7~) of VEP sigificantly increased, but those of short latency components did not change significantly. The peak-to-peak amplitudes inconsistently decreased mainly in the short latency components. In EEG, the power % of θ frequency band increased and that of β2 decreased. Significant positive correlation was found between δ and θ power % of EEG and latencies of VEP mainly in the long latency components (P7~), and significant negative correlation was found between δ and θ power % of EEG and amplitudes of VEP mainly in the long latency components (P6~). These findings indicate the inhibitory effect of VPA mainly on the cerebral cortex through GABA neuron system

The acute effects of antidepressants on the human AEP (Auditory Evoked Potential) and EEG

The acute effect of clomipramine hydrochloride (CMI) was studied by auditory evoked potential (AEP) and compared with those of mianserin hydrochloride (MSR), with each 12 and 16 healthy male subjects, respectively. In the two experimental session on different days, CMI (0.5mg/kg) or MSR (0.3mg/kg) were orally administered for each subjects. EEGs containing AEPs evoked by click stimuli once every 5 sec were derived from the two derivations ( 3ch : Cz→A1+2 , 6ch : Cz→T5) and recorded into magnetic tape. Reproducing the tape, AEPs before and 120 min after the administration of these drugs, with 1024 msec of analysis time were obtained by averaging 100 responses, and EEGs were subjected to the frequency analysis. The changes of the waveform of group mean AEP were studied. Individual AEPs were subjected to the component analysis, and to the statistical assessment together with EEG. The following, statistically significant results were obtained. 1. After the administration of CMI, only P8 and N8 latencies of long latency components significantly increased (P<0.05), while the peak-to-peak amplitudes of middle latency components significantly increased (P<0.01, P<0.05). In EEG, the α1 power% significantly increased (P<0.01). In conclusion, stimulatory effect of CMI besides inhibitory effect was verified by AEP. 2. After the administration of MSR, P2 and P3 latencies of the middle latency components and those of long latency components (P7~) significantly increased (P<0.01, P<0 05). All of significant changes were decrease for the peak-to-peak amplitudes (P<0.01, P<0.05). In EEG, the power% were significantly increased for δ and θ, but significantly decreased for α2 and β2 (P<0.01, P<0.05). In conclusion, sedative effect of MSR was verified by AEP

The acute effects of antidepressants on the human VEP and EEG

The acute effects of clomipramine hydrochloride (CMI), tricyclic antidepressant, were studied and compared with those of mianserin hydrochloride (MSR), tetracyclic antidepressant, by visual evoked potential (VEP), with each 16 and 12 healthy male subjects, respectively. In the two experimental session on different days, CMI (0.5mg/kg) or MSR (0.3mg/kg) were orally administered for each subject. EEGs containing VEPs evoked by flash stimuli once every 5sec were derived from the two derivations (2ch : O1→ A1 + 2, 5ch : O1→Cz) and recorded into magnetic tape. Reproducing the tape, VEPs before and 120min after the administration of each drug, with 1024msec of analysis time, were obtained by averaging 100 responses, and EEGs were subjected to the frequency analysis. The changes of the waveform of group mean VEP were studied and compared between these drugs. Individual VEPs were subjected to the component analysis, and to the statistical assessment together with EEG. The following, statistically significant, results were obtained. 1. After the administration of CMI, both latencies and peak-to-peak amplitudes of VEP did not significantly change. In EEG, the power% of α1 frequency band increased. These findings indicate that few effect of CMI on the visual system. 2. After the administration of MSR, latencies of short latency components (P3 and N3) significantly increased and peak-to-peak amplitudes of short latency components (P3-N3 and N3-P4) significantly decreased in VEP. In EEG, the power% of δ and θ frequency band increased, and that of α2 and β2 decreased. These findings indicate the inhibitory effect of MSR mainly on the lateral geniculate body and the optic radiation in the visual system. 3. From these results, it was considered that CMI has less effect on depression with anxiety or irritability than MSR

The acute effects of antidepressant on the human SEP (Somatosensory Evoked Potential) and EEG

The acute effects of clomipramine hydrochloride (CMI) and mianserin hydrochloride (MSR) on somatosensory evoked potential (SEP) were studied with each 12 and 16 healthy male subjects, respectively. In the two experimental sessions, CMI (0.5mg/kg) or MSR (0.3mg/ kg) was orally administered for each subject. EEGs containing SEPs evoked by electric stimuli, once every 5 sec, were derived from the two derivations (monopolar : C3'→A1+2, bipolar : C3'→F3'), and recorded into magnetic tape. Reproducing the tape, SEPs before and 120 min after the administration of these drugs, with 1024 msec of analysis time, were obtained by averaging 100 responses, and EEGs were subjected to the frequency analysis. The changes of the waveform of group mean SEP were studied. Individual SEPs were subjected to the component analysis, and to the statistical assessment together with EEG. The following, statistically significant (P<0.01, P<0.05), results were obtained. 1. After the administration of CMI, the latencies were significantly decreased for the early middle latency component (P2 and N2), and significantly increased for the long latency component (monopolar : P6~, bipolar : P7~). While those of late middle latency component (P4~P5) did not change significantly. The amplitudes of middle latency component (P3 and P4) increased significantly. In EEG, the power % were significantly increased for α1. In conclusion, stimulatory properties of CMI was verified by SEP. 2. After the administration of MSR, the latencies were significantly increased for the almost all middle and long latency component. The amplitudes of middle and long latency components (N4, P5 and P6) decreased significantly. In EEG, the power % were significantly increased for δ and θ, and significantly decreased for α2 and β2. In conclusion, sedative properties of MSR was verified by SEP