Effects of cannabis sativa on ultrastructure of the synapse in monkey brain

Harper, Jon W.; Heath, Robert G.; Myers, Walter Dean

doi:10.1002/jnr.490030202

Cited by 36 publications

(8 citation statements)

References 25 publications

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“…Animal studies have demonstrated cellular changes associated with chronic cannabis exposure, especially in prefrontal, hippocampal, and cerebellar regions among mice (Childers & Breivogel, 1998;Ghozland et al, 2002;Misner & Sullivan, 1999), rats (Carta et al, 1998;Chan et al, 1998;Landfield et al, 1988;Romero et al, 1995;Rubino et al, 1997), and primates (Harper et al, 1977;Heath et al, 1980). Morphometric studies conducted among adult marijuana users have yielded conflicting results.…”

Section: Introductionmentioning

confidence: 99%

Neuropsychological functioning in adolescent marijuana users: Subtle deficits detectable after a month of abstinence

Medina

Hanson

Schweinsburg

et al. 2007

J. Inter. Neuropsych. Soc.

258

259

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In adults, studies examining the long-lasting cognitive effects of marijuana use demonstrate subtle deficits in attention, executive function, and memory. Because neuromaturation continues through adolescence, these results cannot necessarily generalize to adolescent marijuana users. The goal of this study was to examine neuropsychological functioning in abstinent marijuana using and demographically similar control adolescents. Data were collected from 65 adolescent marijuana users (n 5 31, 26% females) and controls (n 5 34, 26% females) 16-18 years of age. Extensive exclusionary criteria included independent psychiatric, medical, and neurologic disorders. Neuropsychological assessments were conducted after . 23 days of monitored abstinence. After controlling for lifetime alcohol use and depressive symptoms, adolescent marijuana users demonstrated slower psychomotor speed ( p , .05), and poorer complex attention ( p , .04), story memory ( p , .04), and planning and sequencing ability ( p , .001) compared with controls. Post hoc analysis revealed that the number of lifetime marijuana use episodes was associated with poorer cognitive function, even after controlling for lifetime alcohol use. The general pattern of results suggested that, even after a month of monitored abstinence, adolescent marijuana users demonstrate subtle neuropsychological deficits compared with nonusers. It is possible that frequent marijuana use during adolescence may negatively influence neuromaturation and cognitive development. (JINS, 2007, 13, 807-820.)

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Section: Introductionmentioning

confidence: 99%

Neuropsychological functioning in adolescent marijuana users: Subtle deficits detectable after a month of abstinence

Medina

Hanson

Schweinsburg

et al. 2007

J. Inter. Neuropsych. Soc.

258

259

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“…Chronic administration of THC to rats and primates has been shown to result in dose-dependent neurotoxic changes in brain regions that are rich in cannabinoid receptors. Specifi cally, THC-induced neurotoxic eff ects are prominent within the hippocampus (Heath et al ., 1980 ;Scallet et al ., 1987 ;Landfi eld et al ., 1988 ;Chan et al ., 1998 ;Lawston et al ., 2000 ), amygdala (Heath et al ., 1980 ), septum (Harper et al ., 1977 ;Myers and Heath., 1979 ) and cerebral cortex (Harper et al ., 1977 ;Downer et al ., 2001 ). Th ese neurotoxic eff ects include shrinkage of neural cell nuclei and bodies (Heath et al ., 1980 ;Scallet et al ., 1987 ) and reductions in pyramidal cell density (Lawston et al ., 2000 ), dendritic length (Landfi eld et al ., 1988 ) and number of synapses (Heath et al ., 1980 ).…”

Section: Evidence From Animal Studiesmentioning

confidence: 99%

Does cannabis cause lasting brain damage?

Solowij¹,

Yücel²,

Lorenzetti³

et al. 2011

Marijuana and Madness

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“…(Katona et al, 1999;Domenici et al, 2006). Some previous investigations are pointing toward the enlargement of the synaptic cleft in the septal region under the influence of THC (Harper et al, 1977), although prolonged exposure to WIN55,212-2, (THC agonist) but not THC, desensitized the protective effect. Treating cells that had undergone postsynaptic density protein loss with WIN55,212-2 reversed the loss and enabled recovery of a full complement of synapses (Kim et al, 2008).…”

Section: (Received 4 Th July 2012)mentioning

confidence: 94%

“…These synapses are characterized by a thickened postsynaptic cytoplasmic opacity bordering the region of synaptic contact and by a population of spherical vesicles. Only those fine structures with clear pre-and postsynaptic membranes were included, so as to ensure exact cross-sectional measurement of the cleft (Harper et al, 1977). We used 120 representative figures (60 from the experimental and 60 from the control groups).…”

Section: Perfusion Procedures and Tissue Preparationmentioning

confidence: 99%

See 1 more Smart Citation

Effects of tetra hydro cannabinol to the dendritc tree and synapses of the accumbens nucleus of wistar rats

Dimitrijević¹,

Aksić²,

Aleksić³

et al. 2013

ACTA VET-BEOGRAD

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Cannabis is one of the most widely used intoxicants; almost half of all 18 year olds in the USA and in most European countries admit to having tried it at least once, and ~10% of that age group are regular users. Δ9-Tetrahydrocannabinol (THC), the principal psychoactive ingredient in marijuana, produces euphoria and relaxation and impairs motor coordination, time sense, and short term memory. In the hippocampus, CBs inhibit GABA release from a subset of interneurons and inhibit glutamate release from principal neurons. Cannabinoids are reported to produce both rapid and long-term changes in synaptic transmission. Our study was carried out on ten male rats out of which brains of six of them were used as the representative sample for electron microscope analysis, while 4 were used for light microspcopy performed by Golgi method. Three were exposed to THC and 3 were controls. Axodendric synapses in the core and shell of the accumbens nucleus (AN) were studied under electron microscope. The results have shown widening of the synaptic cleft in the shell of AN. This result is a leading point to our further investigations which are going to involve a behavioral component, and different aspects of morphological studies. [Projekat Ministarstva nauke Republike Srbije, br. III 41020

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Effects of cannabis sativa on ultrastructure of the synapse in monkey brain

Cited by 36 publications

References 25 publications

Neuropsychological functioning in adolescent marijuana users: Subtle deficits detectable after a month of abstinence

Neuropsychological functioning in adolescent marijuana users: Subtle deficits detectable after a month of abstinence

Does cannabis cause lasting brain damage?

Effects of tetra hydro cannabinol to the dendritc tree and synapses of the accumbens nucleus of wistar rats

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