Molecular Genetics and Psychopharmacology

In recent years the psychopharmacologist has paid increasing attention to the examination of brain proteins with which psychotropic drugs react, and also the molecular mechanisms that control the synthesis and cellular function of these proteins. For this reason, any understanding of psychopharmacology requires some knowledge of the basic techniques of molecular genetics. 

The role of DNA in storing and transferring genetic material is dependent on the properties of the four bases. These bases are complementary in that guanine is always associated with cytosine, and adenosine with thymine. Watson and Crick, some 40 years ago, showed that the stability of DNA is due to the double helix structure of the molecule that protects it from major perturbations. Information is ultimately transferred by separating these strands which then act as templates for the synthesis of new nucleic acid molecules. 

There are two ways in which DNA molecules may act as templates. Firstly, DNA is used as a template for replicating additional copies during cell division. This occurs by free deoxyribonucleotides binding to the complementary bases of the exposed DNA strand and then being linked by the enzyme DNA polymerase to form a new DNA double helix. Secondly, small sections of the DNA molecule are used as a template for the synthesis of messenger ribonucleotides (mRNAs) which are responsible 

Fundamentals of Psychopharmacology. Third Edition. By Brian E. Leonard 2003 John Wiley Sons, Ltd. ISBN 0 471 52178 7 

The human genome contains approximately 100000 genes which are distributed with a total DNA sequence of 3 billion nucleotides. The DNA of the human genome is divided into 24 exceptionally large molecules each of which is a constituent of a particular chromosome, of which 22 are autosomes and two are sex chromosomes (X and Y chromosomes). 

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Buckland PR and McGuffin P (2000). Molecular genetics of schizophrenia. In MA Reveley and JFW Deakin (eds), The Psychopharmacology of Schizophrenia (pp. 71-88). Edward Arnold, London. 

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