INTRODUCTION TO CNS AND ITS NEUROTRANSMITTERS

DR.RAHUL

Non specific CNS stimulants

Act by blocking inhibitory neurotransmission Direct excitation EXAMPLES:

Cocaine Alcohol Caffeines Methylxanthines

Levels of CNS Depression

Calming Drowsiness (sedation) Conscious sedation Sleep (hypnosis) Unconsciousness Surgical anesthesia Coma Respiratory collapse Cardiovascular collapse

Death

Topics covered under CNS

Sedative Hypnotics Preanaesthetic

Medications General Anesthesia Opioid analgesics

Anti-parkinsonian agents Antiepileptics Psychopharmacology :

Antipsychotics Antidepressants Anti maniac

EXCITATORY

INHIBITORY

GLUTAMATE RECEPTORS

GABAergic SYNAPSE

GABA

glutamate

glucose

Cl-

GAD

Dopamine SystemDopamine System

Dopamine System

There are four major pathways for the dopaminergic system in the brain:

I. The Nigro-Stiatal Pathway.

II. The Mesolimbic Pathway.

III. The Mesocortical Pathway.

IV. The Tuberoinfundibular Pathway.

Catecholamines

Tyrosine Tyrosine hydroxylase

L-Dopa Dopa decarboxylase

Dopamine (DA) Dopamine hydroxylase

Norepinephrine (NE)(Noradrenaline)

Phenylethanolamine-

-N-methyltransferase

Epinephrine (EPI)(Adrenaline)

Dopamine Synapse

DA

L-DOPA

Tyrosine

Tyrosine

Dopamine System

DOPAMINE RECEPTORS

There are at least five subtypes of receptors:

Receptor

D1

D2

D3

D4

D5

Dopamine Reuptake System

Serotonetgic transmissionSerotonetgic transmission

Neurotransmitter

Substance produced in the neuron (synthesized), contained and secreted by that neuron to transmit information to postsynaptic target.