Cannabis physiology

Several physiological roles of endocannabinoids have been identified, including memoiy, cognition, movement, and pain perception (Stella et al. 1997). Elucidation of the endocannabinoid systems is essential to the understanding of the effects of cannabis. There are both similarities and some pointed differences between the effects of exogenous and endogenous cannabinoids. 

Cannabis has been used by humans for thousands of years for both psychoactive and non psychoactive purposes. It has long been known and remains in popular use for recreational purposes. Through the study of cannabis, we have discovered new chemical systems in the brain and body, and are just beginning to appreciate their functions. To be certain, cannabis is not an innocuous substance. Its chemical constituents potently act on the nervous system and other physiological systems. Several neurochemical systems in the brain are affected, with consequences in systems governing cognitive, motor, and emotional function. 

An annotated bibliography (3045 references 1964—1974) of marihuana has been published " and the pharmacology of marihuana, " the analysis and biochemical aspects " of Cannabis, and the chemistry of cannabinoids have been reviewed. The analysis of THC and metabolites in physiological fluids has been discussed. ... 

The physiologically active component of cannabis is A -S -rrans-tetrahydrocannabinol, but cannabinol, into which the other less stable cannabinoids change as the plant ages, is inactive. Recent advances in cannabinoids have been reviewed (B-73MI22402) and a survey of the whole area of cannabinoids has been published (76CRV75). 

Emotional distress—including anxiety, depressed mood, and irritability—is a pervasive feature of cannabis withdrawal in human subjects (Budney et al., 2003, 2004 Vandrey et al., 2005, 2008). Likewise, pharmacologically induced cannabi-noid withdrawal in rats is associated with marked anxiety-related behavioral and physiological responses, as well as with activation of CRF-mediated transmission in the limbic system (Rodriguez de Fonseca et al., 1997). 

The significance of transfer of cannabinoids into human breast milk depends on whether it occurs at levels sufficient to elicit physiological or behavioral effects in a nursing infant. Comprehensive development studies of the infants of mothers using cannabis during pregnancy and/or lactation are required. Such studies are now in progress. (14). 

Cannabinoid compounds are components which can be isolated from Cannabis spp. Due to its physiological activity trans-delta-9-tetrahydrocannabinol (A9-THC) is of substantial significance. This compound is also referred to as 6a,7,8,10a-tetradydro-6,6,9-trimethyl-3-pentyl-6H-dibenzo[b,d]pyran-l-ol. 

A9-Tfetrahydrocannabinol (A9-THC), the psychoactive constituent of Cannabis binds to a specific G-protein coupled receptor in the brain. Although the cannabinoid receptor in the rat and in the human has been cloned, its physiological function is unknown. The well established behavioral effects of THC and the abundance and anatomical localization of the receptor in the brain suggest a role for the receptor in the control of movement, memory, emotions and pain modulation, amongst other activities. 

But despite the frequency of such "poisonings", physicians frequently noted, "an overdose has never produced death in man or the lower animals. Not one authentic case is on record in which Cannabis or any of its preparations destroyed life... Cannabis does not seem capable of causing death by chemical or physiological action."... 

Hamilton, H. C. The pharacopoeial requirements for Cannabis sativa. Journal of the American Pharaceutical Association. 1912, 1, 200-203. Hamilton, H. C. Lescohier, A. W., Perkins, R. A. The physiological activity of Cannabis sativa. Journal of the American Pharaceutical Association, 1913, 2, 22-30. 

In contrast, animal research is devoid of many of the above critiques and results are thus not confounded by, for example, polydrug use, low sample sizes, pretreatment differences, etc. Consequently, the main focus of this chapter rests on such animal models and the effects of acute and chronic cannabis administration on learning, memory, and related brain physiology. 

Levine JE (2000) The hypothalamus as a major integrative center. In Conn PM, Freeman ME (eds) Neuroendocrinology in physiology and medicine. Humana Press, Totowa, p 75 Lozano 1 (2001) The therapeutic use of Cannabis sativa (L.) in Arabic medicine. J Cannabis... 

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