Skip to main content

Marijuana and Health (1982) / Chapter Skim
Currently Skimming:

EFFECTS OF MARIJUANA ON THE BRAIN
Pages 80-93

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.


From page 80...
... Effects of marijuana on brain electrical activity and on brain chemistry have been measured, but their significance for brain function is not known because of our limited knowledge of brain-behavior relations. Marijuana causes temporary intoxication and results in changes in brain physiology and chemistry similar to those caused by other intoxicating drugs.
From page 81...
... The monkeys received either chronic exposure to marijuana smoke or chronic injections of A-9-THC. Changes reported to have occurred in the brains included alteration in synaptic*
From page 82...
... have failed to produce measurable changes even though marked behavioral effects were observed. The EEG effect most frequently reported in recent studies has been an increased abundance of alpha waves associated with a slight slowing (about 0.25 Hz)
From page 83...
... If one selects only chronic marijuana users who are in good health, one may be eliminating systematically those who have been adversely affected by use of the drug and who might have shown EEG changes. On the other hand, if one includes in such studies marijuana users who suffer from various illnesses or behavioral disturbances, one might find abnormalities of the EEG that result from these conditions rather than from the marijuana.
From page 84...
... This study demonstrates differences in marijuana effects on EPS according to dose, duration of administration, and task complexity. Acute Effects in Sleep EEG Drugs often produce marked effects on the BEG during sleep, but producing little or no change in the waking EEG.
From page 85...
... . The Costa Rican study concluded there was a lack of evidence of major disturbances of EEG sleep patterns in user subjects studied in situ (Karacan et al., l976)
From page 86...
... Behavioral withdrawal effects were noted, but EEG changes during withdrawal were minimal and there was no evidence of EEG changes persisting beyond the period of A-9-THC ingestion. Two studies that monitored EEG recording from deep brain sites after chronic administration of high doses of marijuana found changes in EEGs from deep brain sites that were not observed in surface areas after drug withdrawal (Fehr et al., l976; Heath, l976; Heath et al., l979)
From page 87...
... However, as described further in Chapter 7, the bulk of the animal literature and some data from human studies suggest that the more prominent effect of marijuana derivatives, especially cannabinol and cannabidiol, is to decrease rather than increase seizure susceptibility (see Karler and Turkanis, l981, for review)
From page 88...
... , have led to the conclusion that A-9-THC acts to inhibit acetylcholine nerve cell networks. The exact nature of this action is not known, but it may be related to the memory deficits produced (Domino, l98l)
From page 89...
... Electron micrographic studies of monkey brains indicating morphologic changes are methodologically flawed and cannot be used as evidence for an effect of marijuana on brain cell morphology. Clear effects on brain electrical activity in human beings and in animals have been found after drug exposure.
From page 90...
... Co, B.T., Goodwin, D.N., Gado, M., et al. Absence of cerebral atrophy in chronic cannabis users.
From page 91...
... Fink, M Effects of acute and chronic inhalation of hashish, marijuana, and delta-9-tetrahydrocannabinol on brain electrical activity in man: Evidence for tissue tolerance.
From page 92...
... Cerebral and cerebellar neurochemical changes and behavioral manifestations in rats chronically exposed to marijuana smoke. Toxicol.
From page 93...
... Crude marihuana extract: EEG and behavioral effects of chronic oral administration in rhesus monkeys. Psychopharmacologia 37:225-233, l974.


This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More information on Chapter Skim is available.