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Biomedical subjects

J C Gillin

Publications and source records attributed to J C Gillin.

At least 271 records · Page 15Linked to original sources

Serendipity in biological psychiatry--a myth?

It is often stated that major biological treatments in psychiatry were discovered by accident or serendipity. Tracing the history of the concept of serendipity, we find that serendipity has been subjected to greatly divergent interpretations. According to the current usage, it is a discovery in which chance was a necessary and/or sufficient condition. With this definition, none of the discoveries of major biological treatments in psychiatry can be labeled serendipitous. The necessary factors common to these discoveries were creative minds that were variably influenced by the zeitgeist and that were persistent in their search for answers. Another important prerequisite was the availability of crucial basic knowledge of many related sciences. We conclude that chance cannot substitute for long-term research and that the latter is the most likely way to lead to valuable discoveries.

History, 18th Century↗

Comparison of behavioral effects of systemic L-DOPA and intracranial dopamine in mesolimbic forebrain of nonhuman primates.

The systemic administration of L-DOPA and carbidopa to six rhesus and four squirrel monkeys produced an initial period of depressed activity followed by increased locomotion, hypervigilance, involuntary oral-facial movements and a gnawing syndrome. The squirrel monkey exhibited a depressed phase, locomotor stimulation, searching behavior, stereotypic grooming and gnawing syndrome. Most of these activities were prevented by pretreatment with 0.1 mg/kg haloperidol. Bilateral injection of 100 microgram dopamine into the mesolimbic forebrain of four squirrel monkeys also produced an initial depression followed by hyperactivity similar to that produced by L-DOPA, but without gnawing. A stereotyped submissive or juvenile posturing occurred in three animals. These DA-induced activities were blocked by 0.1 mg/kg haloperidol. Similar injection of 100 microgram L-norepinephrine produced a profound depression followed by moderate activity coupled with loss of extensor muscle strength in the legs. Bilateral injection of 300 microgram dopamine into the nucleus accumbens of a rhesus monkey produced stereotypic pacing. These data confirm in primates the importance of dopaminergic mechanisms of the mesolimbic forebrain in locomotor activity and behavior.

Animals↗

Scopolamine-induced muscarinic supersensitivity in normal man: changes in sleep.

Scopolamine (6 microgram/kg) was administered on 3 consecutive mornings to normal human subjects. Sleep recordings obtained at night (when the central anticholinergic effect of the morning scopolamine was no longer present) indicated a significant reduction in latency to REM-sleep onset on the nights following the second and third injections. This effect is opposite to the direct pharmacological action of nighttime administration of scopolamine (i.e., prolongation of REM latency). In addition, total sleep time and sleep efficiency were reduced, and sleep latency was increased. Furthermore, scopolamine pretreatment on 2 consecutive mornings also potentiated the REM-inducing effect of arecoline, a central muscarinic agonist. These data are consistent with the development of cholinergic supersensitivity following cholinergic blockade.

Adult↗

Muscarinic supersensitivity: a possible model for the sleep disturbance of primary depression?

The sleep changes induced in normal volunteers following the administration of scopolamine on 3 consecutive mornings resemble many of the abnormalities observed in the sleep of patients with primary depression: increased sleep latency and reduced rapid eye movement (REM) latency, total sleep time, and sleep efficiency. Furthermore, in a multivariate discriminant analysis--previously shown to distinguish the sleep records of depresed patients from those of normal controls and insomniac patients--the records from baseline nights were selected as normal and those after scopolamine as predominately depressed. Those observations suggest to us that muscarinic supersensitivity in normals may function as a pharmacological model for the sleep disturbances of depression.

Depression↗

Anticonvulsant properties of betaine.

It has been shown previously that convulsions induced by homocysteine are blocked by betaine. In the present study, betaine was found to block the induction of convulsions by electroconvulsive shock and by pentylenetetrazol at least at effectively as it blocked convulsions induced by homocysteine. Thus, betaine has a general anticonvulsant action, the reason for which is unknown.

Animals↗

REM architecture changes in bipolar and unipolar depression.

The authors compared total night sleep measures and REM sleep architecture values for normal control subjects (N = 36), unipolar depressed patients (N = 36), and bipolar depressed patients (N = 22). The unipolar and bipolar patients had significantly greater fragmentation of REM periods than control subjects, and bipolar patients showed greater fragmentation of REM periods than unipolar patients. In both the unipolar and bipolar samples, the duration of successive REM periods was related to the total number of REM periods during sleep.

Bipolar Disorder↗

Phenylethylamine in rhesus monkeys: interactions with alpha-methyl-para-tyrosine and l-dopa.

Rhesus monkeys, pretreated with alpha-methyl-para-tryosine (AMPT) and subsequently injected with phenylethylamine (PEA), did not demonstrate the characteristic amphetamine-like PEA effects. However, when AMPT pretreatment was followed with l-dopa and then PEA injection, PEA effects were restored. These results are compatible with a dopamine theory of schizophrenia.

Animals↗

Clinical effects of L-5-hydroxytryptophan administration in chronic schizophrenic patients.

L-5-Hydroxytryptophan (L-5HTP) and the peripheral decarboxylase inhibitor carbidopa were administered to chronic schizophrenic patients in three separate experiments using a double-blind placebo-controlled crossover design. The three experiments were: (i) L-5HTP administration to 15 patients who had been withdrawn from all neuroleptic medication; (ii) L-5HTP administration to seven patients maintained on haloperidol; (iii) L-5HTP administration to nine patients maintained on chlorpromazine. Although the groups were diagnostically homogeneous, individual responses were highly variable. Considering each group as a whole, the only significant changes in rated psychosis consisted of an increase in the first group consequent to coming off neuroleptic medication and an increase in psychosis scores associated with adding L-5HTP to chlorpromazine. Neuroleptics apparently sensitize the central nervous system to the effects of L-5HTP loading. Acute exacerbations of psychosis induced by L-5HTP can be reversed by neuroleptics. Our experience does not give encouragement to the hypothesis that schizophrenic illnesses arise consequent to a deficit of serotonergic function that can be treated by giving a serotonin precursor in pharmacological quantities.

5-Hydroxytryptophan↗

The relationship between changes in REM sleep and clinical improvement in depressed patients treated with amitriptyline.

EEG sleep recordings were obtained on consecutive nights from six hospitalized depressed patients before, during, and after treatment with amitriptyline for a total of 370 nights of data, about 85% of all nights of the study. Amitriptyline significantly reduced time spent in rapid eye movement (REM) sleep and prolonged the REM latency throughout the treatment period. Three patients who improved during treatment showed a REM rebound when amitriptyline was discontinued, whereas three patients who did not improve showed no REM rebound.

Aged↗

Human serial learning: enhancement with arecholine and choline impairment with scopolamine.

Arecholine (4 milligrams), a cholinergic agonist, and choline (10 grams), a precursor of acetylcholine, significantly enhanced serial learning in normal human subjects. The subjects received methscopolamine prior to both arecholine and placebo injections. Conversely, scopolamine (0.5 milligram), a cholinergic antagonist, impaired learning and this impairment was reversed by arecholine and choline and the impairment after scopolamine were inversely proportional to the subject's performance on placebo; that is, "poor" performers were more vulnerable to both the enhancing effect of cholinergic agonist and precursor and the impairment after cholinergic antagonist than "good" performers.

Acetylcholine↗

Physostigmine alters onset but not duration of REM sleep in man.

Physostigmine (1.0mg) or placebo were administered intravenously over 1-h period to seven male normal volunteers beginning 35 min after sleep onset. The results indicate that physostigmine induced the onset of REM sleep but did not significantly alter the duration of individual REM sleep periods. Physostigmine significantly shortened the REM latency and the duration of the second nonREM period. After inducing the onset of the first REM period(s); physostigmine also appeared to advance succeeding REM-nonREM sleep cycles relative to sleep onset even when the duration of each cycle was unaffected.

Adult↗

Tolerance to the increased locomotor activity produced by L-5-hydroxytryptophan following peripheral decarboxylase inhibition in mice.

The development of tolerance to hyperactivity produced by L-5-hydroxytryptophan (5-HTP) was studied in mice pretreated with the peripheral decarboxylase inhibitor MK-486. The results of Experiment I indicated that partial tolerance developed to 5-HTP given twice daily (i.p.) at a dose of 400 mg/kg, but not at a dose of 800 mg/kg. Sustained hyperactivity at the greater dose (800 mg/kg) apparently resulted from the induction of seizures and stereotypy rather than increased locomotor activity. When 5-HTP (400 mg/kg) or saline was administered three times daily (Experiments II and III), the locomotor activity of saline control groups did not differ significantly from chronic 5-HTP-treated groups, but both differed significantly from that of acute 5-HTP-treated animals. Cessation of treatments resulted in a recovery of 5-HTP-induced hyperactivity for experimental animals when later retested. These findings suggest that mice develop tolerance to the effects of 5-HTP on locomotor activity and agree with the hypothesis that behavior change is more closely correlated with the rate of change in concentration of neurotransmitters than the absolute concentrations.

5-Hydroxytryptophan↗