THE THERAPEUTIC AND PATHOLOGIC BASES OF NEUROLOGIC DISORDERS REST ON CNS TRANSMISTERS:-

Azikiwe C. C. A., Enye J. C., Ifezulike C. C. and Anowi C. F.

ABSTRACT

Therapeutic connotes treatment or management of a disease or disorder while pathologic connotes causative and, or processes of a disease or disorder. Central nervous system (CNS) transmitters are biologic molecules, neuronal or extraneuronal that are involved in the transmission or modulation of signals from one neuron to the other or from neuron to an effecter cell or tissue in order to effect an action in the brain. The action could be excitatory or inhibitory. CNS transmitters can broadly be sub-classified into three based on their site of production and actions in the brain. These are Neurotransmitters that are produced in the neuron, stored in the vesicles, destroyed in the neuron and could act as fast or slow transmitters. Examples of which include glutamate, aspartate, gamma amino butyric acid(GABA), dopamine, acetylcholine, serotonin, histamine, adrenaline and noradrenalin. Neuromodulators that may be produced in the neuron, may be destroyed in the neuron and act predominantly as slow transmitters. A single Neuromodulator may speed up the action of a slow Neurotransmitter, modify the action of a fast Neurotransmitter or combine with another modulator to effect a brain action. Examples of which include purines, pyrimindes, prostaglandins, nitric oxide, hydrogen sulphide and some second messengers. Neurotrophic factors that are neither produced nor destroyed in the neurons and are essentially involved in neuronal gene remodeling. Strictly, speaking they are not CNS transmitters but, are essential in transmission. They include substance-P, enkaphalins, endorphins and the host varieties of growth factors cum derived growth factors. Diseases or disorders like seizures/convulsions, Parkinsonism, Alzheimer’s, Depressions, Mania, Anxiety, Hypertensions, schizophrenia, autism, huntington’s disease, tardive dyskinesia, myasthenia gravis, among others are mediated by one CNS transmitter or the other. Theories in CNS like Mono Amine theory of Affective disorders and Dopamine theory of Schizophrenia implies the classical antidepressants and classical antipsychotics obeying these theories respectively in their mechanisms of actions. Benzodiazepines, relieve anxiety via their actions on GABA. Anxiety is also relieved by buspirone, gepirone and ipsapirone via their effects on serotonine (precisely 5HT1A). Alpha 2 methyldopa, Resapine, Clonidine, Prazocine etc bring down high blood pressure via their actions on adrenaline/noradrenaline. Levodopa, Carbidopa, Entacapone, Tolcapone, Selegelline etc bring relieve in Parkinsonism via actions on dopamine. Conclusions: From afore going and several other numerous instances, one can clearly conclude that CNS transmitters play very crucial roles in mediation of neurological diseases and also form the bedrock in the drug management of these disorders. A clear understanding of CNS transmission is thus sine qua nom to a good management of neurological diseases/disorders.

Keywords: Neurological diseases/disorders, CNS transmitters, Alzheimer and food additives, Pathogenesis, Drugs treatment of CNS disorders.