Philip A. Berger

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The hypotheses of relative cholinergic underactivity in Huntington's disease, tardive dyskinesia, mania, and schizophrenia were pharmacologically investigated, using physostigmine and choline chloride. Intravenous physostigmine improved the involuntary movements of all of four patients with tardive dyskinesia and three of six patients with Huntington's(More)
The authors investigated platelet monoamine (MAO) activity in 40 chronic schizophrenic patients, 55 normal control subjects, and 16 hospitalized control subjects. The mean platelet MAO activity for the chronic schizophrenic patients was significantly lower than the mean in either control group. There were no significant differences between the mean platelet(More)
Because both long-term adrenoceptor agonist administration and antidepressant treatment in animals down-regulate CNS beta-adrenoceptors and attenuate brain adenylate cyclase activity, beta-adrenoceptor agonists may also possess antidepressant properties. We compared the effects of the centrally acting beta-adrenoceptor agonist clenbuterol (5, 10 and 35(More)
Event-related potentials in two auditory target detection paradigms and two auditory paradigms without overt tasks were studied in 22 schizophrenic, 21 depressed, and 28 matched control subjects meeting Research Diagnostic Criteria. In the target detection paradigms, schizophrenics showed a pattern of reduced N120 amplitude and shorter P200 latency to(More)
Fifteen schizophrenics and 15 age-matched controls performed a reaction time (RT) task. A Bernoulli sequence of 85 dB SPL, 50 msec, 800 c/sec (P = 0.85) and 1200 c/sec (P = 0.15) tones was presented with an interstimulus interval of 1 sec. Subjects were instructed to press a button quickly upon hearing the 1200 c/sec tone. If a subject failed to respond(More)
In an effort to find electrophysiologic correlates of dopaminergic disease in man, we measured oscillatory potentials of the electroretinogram in normal and unmedicated schizophrenic subjects, and in rabbits given D1 agonist or antagonist drugs. We found highly reproducible oscillatory potentials in twelve male schizophrenics that were indistinguishable(More)
Previous work has suggested that normal subjects are able to recognize and correct their own errors of movement without using exteroceptive signals. This ability may be impaired in schizophrenia. Twelve normal subjects, 12 alcoholics, and 14 schizophrenics performed a step-function tracking task designed to prevent the use of exteroceptive signals in(More)
The probenecid-induced accumulation of the acidic metabolites of dopamine and serotonin is widely used to estimate the CNS turnover of these amines in human subjects. The theoretical basis of the probenecid test is discussed, including the assumptions on which the test is based, and the limitations of the procedure. Suggestions are offered on appropriate(More)
Increased serotonergic activity in animals has been associated with a variety of stereotyped motor behaviors. In addition, serotonin facilitates brainstem, reticular, and spinal motor neuronal activity implicated in the expression of these behaviors. This report presents positive correlations between both peripheral (platelet serotonin levels) and central(More)