NEUROBIOLOGY OF PYRIDOXINE

Pyridoxal 5'-phosphate (PLP) is the major coenzymatic form of pyridoxine. There are over one hundred known pyridoxal 5'-phosphate-dependent reactions, most of which are involved in the metabolism of various amino acids . Pyridoxamine 5'-phosphate can function in aminotransf erase reactions by the cyclic regeneration of the two active phosphate forms. Pyridoxal 5'-phosphate-dependent reactions studied in the nervous system are involved in the catabolism of various amino acids. The putative neurotransmitters , dopamine, norepinephrine , serotonin , histamine , aminobutyric acid and taurine , as well as the sphingoiipids and poly amines are synthesized by PLP-dependent enzymes. Of these enzymes, three ( glutamic acid decarboxylase , 5-hydroxytryptophan decarboxylase and crnithine decarboxylase) seem to have crucial roles (Fig. '). The clinical effects of pyridoxine deficiency can be explained on the basis of the known decreases in the activities of these enzymes

Neurotransmitters Functional Balance in Neurodegenerative Disease Management:recent Advances

The recent developments in neurobiology have rendered new prominence and potential to study about the structure and function of brain and related disorders. Human behaviour is the net result of neural control of the communication between brain cells. Neurotransmitters are chemicals that are used to relay, amplify and modulate electrical signals between neurons and/or another cell. It mediates rapid intercellular communication through the nervous system by interacting with cell surface receptors. These receptors often trigger second messenger signaling pathways that regulate the activity of ion channels. The functional balance of different neurotransmitters such as Acetylcholine (Ach), Dopamine (DA), Serotonin (5-HT), Norepinephrine (NE), Epinephrine (EPI), Glutamate and Gamma amino butyric acid (GABA) regulates the growth, division and other vital functions of a normal cell / organism (Sudha, 1998). Any change in neurotransmitters' functional balance will result in the failure of cell function and may lead to the occurrence of diseases. Abnormalities in the production or functioning of neurotransmitters have been implicated in a number of neurological disorders like Schizophrenia, Alzheimer's, Epilepsy, Depression and Parkinson's disease. Changes in central and peripheral neuronal signaling system is also noted in diabetes, cancer, cell proliferation, alcoholism and aging. Elucidation of neurotransmitters receptor interaction pathways and gene expression regulation by second messengers and transcriptional factors in health and disease conditions can lead to new small molecules for development of therapeutic agents to improve neurological disease conditions. Increased awareness of the global effects of neurological disorders should help health care planners and the neurological community set appropriate priorities in research, prevention, and management of these diseases.