Howard L. Cohen

The effects of ethanol on EEG activity in males at risk for alcoholism

The present investigation examined the effects of placebo (P), low dose (LD) and high dose (HD) ethanol on EEG activity in two groups of males. One group consisted of individuals at high risk for the development of alcoholism (HR, N = 21) while the other consisted of matched, low risk (LR, N = 21) controls. Only one condition (P, LD or HD) was presented each day and condition order was randomized. For each subject, both blood alcohol level(s) (BAL) measured via breathalyzer and EEG activity, using the entire 10/20 international system, were recorded prior to and at intervals of 35, 70, 105 and 140 min after P, LD or HD administration. The Fast Fourier Transform (FFT) was used to calculate power spectral densities (PSD). Measures of relative area under the power spectral curve were obtained for each of the following frequency bands: slow alpha (SA, 7.5-10 Hz), fast alpha (FA, 10.5-13.0 Hz), slow beta (SB, 13.5-19.5 Hz) and fast beta (FB, 20-26 Hz) at electrodes: F3, F4, C3, C4, P3, P4, O1 and O2. The results of repeated measures MANOVA conducted on the normalized values of relative areas revealed that at each electrode examined, ethanol elicited significant changes only in SA activity. Risk group differences in SA activity were observed only at electrodes F3, F4 and P4. These differences were the consequence of differential ethanol effects rather than differences in baseline SA levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Neuroelectric correlates of response production and inhibition in individuals at risk to develop alcoholism

P300 recordings were made from males at high risk (HR) for alcoholism and low-risk (LR) controls, participating in a visual go/no go reaction time paradigm. The go (button press) and no go (inhibit response) stimuli were large and small forms of the same letters. The LR group had significantly larger go than no go P300 amplitudes in the central, parietal, and temporal regions; the HR group manifested no response differences in any region. In the LR group compared to the HR group, both go and no go response amplitudes were larger over the entire head; no group differences in latencies were observed in any region. Surface energy magnitudes paralleled P300 amplitudes and were also larger in the LR group during both go and no go trials. Our findings indicate that HR individuals manifest widespread P300 amplitude deficits while performing a simple information-processing paradigm. These deficits, which may reflect genetic influences, preceded the onset of alcoholism and may function as a phenotypic marker for its development.

Visual P300: An interlaboratory consistency study

The P300 component of the event-related potential is reduced in both abstinent alcoholics and in males at high risk for developing alcoholism. Here, 96 males (mean = 22.1 years) who were part of an interlaboratory (n = 6) consistency study in the national COGA (Collaborative Study on the Genetics of Alcoholism) Project were subjects in a visual target selection paradigm. Each of the participating laboratories used the same experimental design, hardware and software. Each subject received a randomized series of target, nontarget and novel visual stimuli, and upon detecting the target stimulus, was required to make a button press as quickly as possible. Statistical analyses indicated that there were no significant differences in P300 amplitude and latency at the Pz electrode under any of the aforementioned conditions across laboratories. Thus, the interlaboratory consistency of the visual P300 indicates that it may be of utility in a national collaborative study on the genetics of alcoholism.

Ethanol-induced alterations in electroencephalographic activity in adult males.

The present investigation examined the effects of placebo (P), low-dose (LD), and high-dose (HD) ethanol on dectroencephalographic (EEG) activity in 21 healthy, adult Males ([Xmacr ] = 22.7 years). Only one condition (P, LD, or HD) was presented per day and the condition oder was randomized. For each subject, blood-alcohol levels measured via breathalyzer and EEG activity, using the entire 10/20 International System, were recorded both prior to and at intervals of 35, 70, 105, and 140 minutes after P, LD, or HD administration. The Fast Fourier Transform was used to calculate power spectral densities for each EEG recording. Measures of the relative areas unter the power spectral curve were made for each of the following frequency bands: slow alpha (7.5 to 10 Hz); fast alpha (10.5 to 13.0 Hz); slow beta (13.5 to 19.5 Hz); and fast beta (20 to 26 Hz) at electrodes F3, F4, C3, C4, P3, P4, O1, and O2. Repeated-measures multivariate analysis of variance performed on normalized relative area values revealed that ethanol had significant effects on EEG activity at anterior sites: frontal (F3, F4) and central (C3, C4) that presented as increased activity in the slow alpha frequency band. These results suggest a differential responsivity of both cortical region and EEG frequency band to the effects of ethanol ingestion.

Age-related changes in power spectra of efferent phrenic activity in the piglet

Power spectral analysis of phrenic nerve discharge in neonatal swine revealed the presence of both high-frequency oscillations (HFO) (95-150 Hz) and medium-frequency oscillations (MFO) (15-35 Hz). The HFO was shown to be age-related; the MFO was not. The data indicated that at least one manifestation of maturation of the respiratory rhythm generator is the increase with age of the frequency of the HFO.

Autonomic Nervous System Regulation of Heart Rate in the Perinatal Period

In all vertebrates more advanced than elasmobranch, cardiac muscle is innervated by the autonomic nervous system [15]. There are two major divisions of the autonomic nervous system: the parasympathetic originating in the third, seventh, ninth, and tenth cranial nerves, and the sacral spinal cord region; and the sympathetic system, originating in the thoracolumbar regions of the spinal cord. For both subdivisions of the autonomic nervous system, the cells of origin within the central nervous system project to ganglia located peripherally. The cells of these ganglia send their axons to the various effector organs throughout the body. The transmitter for all preganglionic neurons is acetylcoholine (ACh), while the post ganglionic neurons of the parasympathetic nervous system are also cholinergic. With few exceptions, post-ganglionic neurons of the sympathetic nervous system are adrenergic, utilizing norepinephrine (NE) as their neurotransmitter. In all vertebrates the heart is innervated by a parasympathetic inhibitory system, and a sympathetic excitatory system.

Temporal recovery of auditory evoked potentials in individuals at risk for alcoholism

The present investigation examined auditory evoked potential (AEP) recovery functions in both high-risk (HR, N = 23, mean = 22.3) and low-risk (LR, N = 27, mean = 23.0) males. A series of binaural auditory stimuli, with randomly interposed interstimulus intervals (ISIs) of 0.5, 1.0, and 10.0 s, were used to elicit the N1 and P2 components of the AEP. Scalp potentials were recorded from the 19 electrodes comprising the 10/20 International System. For purposes of statistical analysis, five electrode groups were created: frontal (F), central (C), parietal (P), occipital (O), and temporal (T). The results of within-group MANOVA demonstrated that in both LR and HR individuals, increases in the ISI produced significant N1 and P2 amplitude increases without significant latency differences. These amplitude increases occurred primarily in the F and C regions. However, the results of between-group MANOVA indicated that there were no differences in the recovery functions of the two risk groups. Our results indicate that in both LR and HR individuals, recovery functions are responsive to changes in increasing ISI. However, they did not effectively discriminate between risk groups. It is speculated that risk group differences may be apparent with the use of an ethanol challenge.

Power spectral analysis of the baroreflex in neonatal swine.

The baroreflex was observed in neonatal swine as young as 4 h of age. Bolus injections of Na nitroprusside (NP) and phenylephrine (PE), induced changes in blood pressure and elicited changes in both heart rate and in cervical sympathetic and splanchnic discharge; changes in sympathetic discharge were reflected in altered power spectral magnitude. Measures of heart rate showed that the magnitude of the PE-induced decreases was positively correlated with increasing postnatal age. The results indicate that the baroreflex, as indicated by changes in sympathetic discharge and heart rate, is present in early neonatal swine.