co transmission

neuronal cotransmission

1. Cotransmission The transmitter is stored in the same neuron but indistinct synaptic vesicles or locations. HARI V Research Scholar Sri venkateswara college of pharmacy

2. O ne neurone- One transmission On stimulation most peripheral and Central neurone have been shown to release more than one active substance. In the ANS besides the primary transmitter, Acetylcholine and nor adrenaline , neurone have been found to to elaborate Purines( ATP, adenosine), peptides( vasoactive Intestinal peptide or VIP, Neuropeptide -Y or NPY , Substance P, enkaphalins, somatostatin etc.), Nitric oxide and prostaglandin as cotransmitters.

3. In most autonomic cholinergic neurones VIP is is associated with acetylcholine, while ATP is associated with both acetylcholine and not adrenaline The transmitter at some parasympathetic sides is nitric oxide and these are called nitregic nerve Neuropeptide Y which causes long lasting vasoconstriction the co transmitter may also serve as an alternative transmitter in its own right exert a trophic influence on the same synoptic structures. Non adrenergic, noncholinergic or NANC Transmission has been demonstrated in the autonomic innervation of the gut, Vas deference, urinary tract, salivary glands and c ertain blood vessels. where nerve stimulation is able to evoke Limited responses even in the presence of total adrenergic and cholinergic blocked

4. Parasympathetic neurons The time course of of the primary transmitter and Cotransmitter is usually different. Vasoactive intestinal peptide of parasympathetic neurones produces a slow and long lasting response, while another on nitric oxide intermediate time course of action between VIP and acetylcholine (fast)

5. Sympathetic neurones The cotransmitter NPY is slower acting and ATP faster acting than noradrenaline